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path: root/fs/proc/proc_sysctl.c
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2019-07-18proc/sysctl: add shared variables for range checkMatteo Croce
In the sysctl code the proc_dointvec_minmax() function is often used to validate the user supplied value between an allowed range. This function uses the extra1 and extra2 members from struct ctl_table as minimum and maximum allowed value. On sysctl handler declaration, in every source file there are some readonly variables containing just an integer which address is assigned to the extra1 and extra2 members, so the sysctl range is enforced. The special values 0, 1 and INT_MAX are very often used as range boundary, leading duplication of variables like zero=0, one=1, int_max=INT_MAX in different source files: $ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l 248 Add a const int array containing the most commonly used values, some macros to refer more easily to the correct array member, and use them instead of creating a local one for every object file. This is the bloat-o-meter output comparing the old and new binary compiled with the default Fedora config: # scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164) Data old new delta sysctl_vals - 12 +12 __kstrtab_sysctl_vals - 12 +12 max 14 10 -4 int_max 16 - -16 one 68 - -68 zero 128 28 -100 Total: Before=20583249, After=20583085, chg -0.00% [mcroce@redhat.com: tipc: remove two unused variables] Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com [akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c] [arnd@arndb.de: proc/sysctl: make firmware loader table conditional] Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de [akpm@linux-foundation.org: fix fs/eventpoll.c] Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com Signed-off-by: Matteo Croce <mcroce@redhat.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Aaron Tomlin <atomlin@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-16fs/proc/proc_sysctl.c: fix the default values of i_uid/i_gid on /proc/sys ↵Radoslaw Burny
inodes. Normally, the inode's i_uid/i_gid are translated relative to s_user_ns, but this is not a correct behavior for proc. Since sysctl permission check in test_perm is done against GLOBAL_ROOT_[UG]ID, it makes more sense to use these values in u_[ug]id of proc inodes. In other words: although uid/gid in the inode is not read during test_perm, the inode logically belongs to the root of the namespace. I have confirmed this with Eric Biederman at LPC and in this thread: https://lore.kernel.org/lkml/87k1kzjdff.fsf@xmission.com Consequences ============ Since the i_[ug]id values of proc nodes are not used for permissions checks, this change usually makes no functional difference. However, it causes an issue in a setup where: * a namespace container is created without root user in container - hence the i_[ug]id of proc nodes are set to INVALID_[UG]ID * container creator tries to configure it by writing /proc/sys files, e.g. writing /proc/sys/kernel/shmmax to configure shared memory limit Kernel does not allow to open an inode for writing if its i_[ug]id are invalid, making it impossible to write shmmax and thus - configure the container. Using a container with no root mapping is apparently rare, but we do use this configuration at Google. Also, we use a generic tool to configure the container limits, and the inability to write any of them causes a failure. History ======= The invalid uids/gids in inodes first appeared due to 81754357770e (fs: Update i_[ug]id_(read|write) to translate relative to s_user_ns). However, AFAIK, this did not immediately cause any issues. The inability to write to these "invalid" inodes was only caused by a later commit 0bd23d09b874 (vfs: Don't modify inodes with a uid or gid unknown to the vfs). Tested: Used a repro program that creates a user namespace without any mapping and stat'ed /proc/$PID/root/proc/sys/kernel/shmmax from outside. Before the change, it shows the overflow uid, with the change it's 0. The overflow uid indicates that the uid in the inode is not correct and thus it is not possible to open the file for writing. Link: http://lkml.kernel.org/r/20190708115130.250149-1-rburny@google.com Fixes: 0bd23d09b874 ("vfs: Don't modify inodes with a uid or gid unknown to the vfs") Signed-off-by: Radoslaw Burny <rburny@google.com> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Seth Forshee <seth.forshee@canonical.com> Cc: John Sperbeck <jsperbeck@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: <stable@vger.kernel.org> [4.8+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Three trivial overlapping conflicts. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-26fs/proc/proc_sysctl.c: Fix a NULL pointer dereferenceYueHaibing
Syzkaller report this: sysctl could not get directory: /net//bridge -12 kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN PTI CPU: 1 PID: 7027 Comm: syz-executor.0 Tainted: G C 5.1.0-rc3+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 RIP: 0010:__write_once_size include/linux/compiler.h:220 [inline] RIP: 0010:__rb_change_child include/linux/rbtree_augmented.h:144 [inline] RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:186 [inline] RIP: 0010:rb_erase+0x5f4/0x19f0 lib/rbtree.c:459 Code: 00 0f 85 60 13 00 00 48 89 1a 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 89 f2 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 75 0c 00 00 4d 85 ed 4c 89 2e 74 ce 4c 89 ea 48 RSP: 0018:ffff8881bb507778 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: ffff8881f224b5b8 RCX: ffffffff818f3f6a RDX: 000000000000000a RSI: 0000000000000050 RDI: ffff8881f224b568 RBP: 0000000000000000 R08: ffffed10376a0ef4 R09: ffffed10376a0ef4 R10: 0000000000000001 R11: ffffed10376a0ef4 R12: ffff8881f224b558 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f3e7ce13700(0000) GS:ffff8881f7300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd60fbe9398 CR3: 00000001cb55c001 CR4: 00000000007606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: erase_entry fs/proc/proc_sysctl.c:178 [inline] erase_header+0xe3/0x160 fs/proc/proc_sysctl.c:207 start_unregistering fs/proc/proc_sysctl.c:331 [inline] drop_sysctl_table+0x558/0x880 fs/proc/proc_sysctl.c:1631 get_subdir fs/proc/proc_sysctl.c:1022 [inline] __register_sysctl_table+0xd65/0x1090 fs/proc/proc_sysctl.c:1335 br_netfilter_init+0x68/0x1000 [br_netfilter] do_one_initcall+0xbc/0x47d init/main.c:901 do_init_module+0x1b5/0x547 kernel/module.c:3456 load_module+0x6405/0x8c10 kernel/module.c:3804 __do_sys_finit_module+0x162/0x190 kernel/module.c:3898 do_syscall_64+0x9f/0x450 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Modules linked in: br_netfilter(+) backlight comedi(C) hid_sensor_hub max3100 ti_ads8688 udc_core fddi snd_mona leds_gpio rc_streamzap mtd pata_netcell nf_log_common rc_winfast udp_tunnel snd_usbmidi_lib snd_usb_toneport snd_usb_line6 snd_rawmidi snd_seq_device snd_hwdep videobuf2_v4l2 videobuf2_common videodev media videobuf2_vmalloc videobuf2_memops rc_gadmei_rm008z 8250_of smm665 hid_tmff hid_saitek hwmon_vid rc_ati_tv_wonder_hd_600 rc_core pata_pdc202xx_old dn_rtmsg as3722 ad714x_i2c ad714x snd_soc_cs4265 hid_kensington panel_ilitek_ili9322 drm drm_panel_orientation_quirks ipack cdc_phonet usbcore phonet hid_jabra hid extcon_arizona can_dev industrialio_triggered_buffer kfifo_buf industrialio adm1031 i2c_mux_ltc4306 i2c_mux ipmi_msghandler mlxsw_core snd_soc_cs35l34 snd_soc_core snd_pcm_dmaengine snd_pcm snd_timer ac97_bus snd_compress snd soundcore gpio_da9055 uio ecdh_generic mdio_thunder of_mdio fixed_phy libphy mdio_cavium iptable_security iptable_raw iptable_mangle iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter bpfilter ip6_vti ip_vti ip_gre ipip sit tunnel4 ip_tunnel hsr veth netdevsim vxcan batman_adv cfg80211 rfkill chnl_net caif nlmon dummy team bonding vcan bridge stp llc ip6_gre gre ip6_tunnel tunnel6 tun joydev mousedev ppdev tpm kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel ide_pci_generic piix aes_x86_64 crypto_simd cryptd ide_core glue_helper input_leds psmouse intel_agp intel_gtt serio_raw ata_generic i2c_piix4 agpgart pata_acpi parport_pc parport floppy rtc_cmos sch_fq_codel ip_tables x_tables sha1_ssse3 sha1_generic ipv6 [last unloaded: br_netfilter] Dumping ftrace buffer: (ftrace buffer empty) ---[ end trace 68741688d5fbfe85 ]--- commit 23da9588037e ("fs/proc/proc_sysctl.c: fix NULL pointer dereference in put_links") forgot to handle start_unregistering() case, while header->parent is NULL, it calls erase_header() and as seen in the above syzkaller call trace, accessing &header->parent->root will trigger a NULL pointer dereference. As that commit explained, there is also no need to call start_unregistering() if header->parent is NULL. Link: http://lkml.kernel.org/r/20190409153622.28112-1-yuehaibing@huawei.com Fixes: 23da9588037e ("fs/proc/proc_sysctl.c: fix NULL pointer dereference in put_links") Fixes: 0e47c99d7fe25 ("sysctl: Replace root_list with links between sysctl_table_sets") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reported-by: Hulk Robot <hulkci@huawei.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-12bpf: Add file_pos field to bpf_sysctl ctxAndrey Ignatov
Add file_pos field to bpf_sysctl context to read and write sysctl file position at which sysctl is being accessed (read or written). The field can be used to e.g. override whole sysctl value on write to sysctl even when sys_write is called by user space with file_pos > 0. Or BPF program may reject such accesses. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-12bpf: Introduce bpf_sysctl_{get,set}_new_value helpersAndrey Ignatov
Add helpers to work with new value being written to sysctl by user space. bpf_sysctl_get_new_value() copies value being written to sysctl into provided buffer. bpf_sysctl_set_new_value() overrides new value being written by user space with a one from provided buffer. Buffer should contain string representation of the value, similar to what can be seen in /proc/sys/. Both helpers can be used only on sysctl write. File position matters and can be managed by an interface that will be introduced separately. E.g. if user space calls sys_write to a file in /proc/sys/ at file position = X, where X > 0, then the value set by bpf_sysctl_set_new_value() will be written starting from X. If program wants to override whole value with specified buffer, file position has to be set to zero. Documentation for the new helpers is provided in bpf.h UAPI. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-12bpf: Sysctl hookAndrey Ignatov
Containerized applications may run as root and it may create problems for whole host. Specifically such applications may change a sysctl and affect applications in other containers. Furthermore in existing infrastructure it may not be possible to just completely disable writing to sysctl, instead such a process should be gradual with ability to log what sysctl are being changed by a container, investigate, limit the set of writable sysctl to currently used ones (so that new ones can not be changed) and eventually reduce this set to zero. The patch introduces new program type BPF_PROG_TYPE_CGROUP_SYSCTL and attach type BPF_CGROUP_SYSCTL to solve these problems on cgroup basis. New program type has access to following minimal context: struct bpf_sysctl { __u32 write; }; Where @write indicates whether sysctl is being read (= 0) or written (= 1). Helpers to access sysctl name and value will be introduced separately. BPF_CGROUP_SYSCTL attach point is added to sysctl code right before passing control to ctl_table->proc_handler so that BPF program can either allow or deny access to sysctl. Suggested-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-03-29fs/proc/proc_sysctl.c: fix NULL pointer dereference in put_linksYueHaibing
Syzkaller reports: kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN PTI CPU: 1 PID: 5373 Comm: syz-executor.0 Not tainted 5.0.0-rc8+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 RIP: 0010:put_links+0x101/0x440 fs/proc/proc_sysctl.c:1599 Code: 00 0f 85 3a 03 00 00 48 8b 43 38 48 89 44 24 20 48 83 c0 38 48 89 c2 48 89 44 24 28 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 fe 02 00 00 48 8b 74 24 20 48 c7 c7 60 2a 9d 91 RSP: 0018:ffff8881d828f238 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8881e01b1140 RCX: ffffffff8ee98267 RDX: 0000000000000007 RSI: ffffc90001479000 RDI: ffff8881e01b1178 RBP: dffffc0000000000 R08: ffffed103ee27259 R09: ffffed103ee27259 R10: 0000000000000001 R11: ffffed103ee27258 R12: fffffffffffffff4 R13: 0000000000000006 R14: ffff8881f59838c0 R15: dffffc0000000000 FS: 00007f072254f700(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff8b286668 CR3: 00000001f0542002 CR4: 00000000007606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: drop_sysctl_table+0x152/0x9f0 fs/proc/proc_sysctl.c:1629 get_subdir fs/proc/proc_sysctl.c:1022 [inline] __register_sysctl_table+0xd65/0x1090 fs/proc/proc_sysctl.c:1335 br_netfilter_init+0xbc/0x1000 [br_netfilter] do_one_initcall+0xfa/0x5ca init/main.c:887 do_init_module+0x204/0x5f6 kernel/module.c:3460 load_module+0x66b2/0x8570 kernel/module.c:3808 __do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x462e99 Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f072254ec58 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000462e99 RDX: 0000000000000000 RSI: 0000000020000280 RDI: 0000000000000003 RBP: 00007f072254ec70 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f072254f6bc R13: 00000000004bcefa R14: 00000000006f6fb0 R15: 0000000000000004 Modules linked in: br_netfilter(+) dvb_usb_dibusb_mc_common dib3000mc dibx000_common dvb_usb_dibusb_common dvb_usb_dw2102 dvb_usb classmate_laptop palmas_regulator cn videobuf2_v4l2 v4l2_common snd_soc_bd28623 mptbase snd_usb_usx2y snd_usbmidi_lib snd_rawmidi wmi libnvdimm lockd sunrpc grace rc_kworld_pc150u rc_core rtc_da9063 sha1_ssse3 i2c_cros_ec_tunnel adxl34x_spi adxl34x nfnetlink lib80211 i5500_temp dvb_as102 dvb_core videobuf2_common videodev media videobuf2_vmalloc videobuf2_memops udc_core lnbp22 leds_lp3952 hid_roccat_ryos s1d13xxxfb mtd vport_geneve openvswitch nf_conncount nf_nat_ipv6 nsh geneve udp_tunnel ip6_udp_tunnel snd_soc_mt6351 sis_agp phylink snd_soc_adau1761_spi snd_soc_adau1761 snd_soc_adau17x1 snd_soc_core snd_pcm_dmaengine ac97_bus snd_compress snd_soc_adau_utils snd_soc_sigmadsp_regmap snd_soc_sigmadsp raid_class hid_roccat_konepure hid_roccat_common hid_roccat c2port_duramar2150 core mdio_bcm_unimac iptable_security iptable_raw iptable_mangle iptable_nat nf_nat_ipv4 nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter bpfilter ip6_vti ip_vti ip_gre ipip sit tunnel4 ip_tunnel hsr veth netdevsim devlink vxcan batman_adv cfg80211 rfkill chnl_net caif nlmon dummy team bonding vcan bridge stp llc ip6_gre gre ip6_tunnel tunnel6 tun crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel joydev mousedev ide_pci_generic piix aesni_intel aes_x86_64 ide_core crypto_simd atkbd cryptd glue_helper serio_raw ata_generic pata_acpi i2c_piix4 floppy sch_fq_codel ip_tables x_tables ipv6 [last unloaded: lm73] Dumping ftrace buffer: (ftrace buffer empty) ---[ end trace 770020de38961fd0 ]--- A new dir entry can be created in get_subdir and its 'header->parent' is set to NULL. Only after insert_header success, it will be set to 'dir', otherwise 'header->parent' is set to NULL and drop_sysctl_table is called. However in err handling path of get_subdir, drop_sysctl_table also be called on 'new->header' regardless its value of parent pointer. Then put_links is called, which triggers NULL-ptr deref when access member of header->parent. In fact we have multiple error paths which call drop_sysctl_table() there, upon failure on insert_links() we also call drop_sysctl_table().And even in the successful case on __register_sysctl_table() we still always call drop_sysctl_table().This patch fix it. Link: http://lkml.kernel.org/r/20190314085527.13244-1-yuehaibing@huawei.com Fixes: 0e47c99d7fe25 ("sysctl: Replace root_list with links between sysctl_table_sets") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reported-by: Hulk Robot <hulkci@huawei.com> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: <stable@vger.kernel.org> [3.4+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-13proc/sysctl: don't return ENOMEM on lookup when a table is unregisteringIvan Delalande
proc_sys_lookup can fail with ENOMEM instead of ENOENT when the corresponding sysctl table is being unregistered. In our case we see this upon opening /proc/sys/net/*/conf files while network interfaces are being deleted, which confuses our configuration daemon. The problem was successfully reproduced and this fix tested on v4.9.122 and v4.20-rc6. v2: return ERR_PTRs in all cases when proc_sys_make_inode fails instead of mixing them with NULL. Thanks Al Viro for the feedback. Fixes: ace0c791e6c3 ("proc/sysctl: Don't grab i_lock under sysctl_lock.") Cc: stable@vger.kernel.org Signed-off-by: Ivan Delalande <colona@arista.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-06-12treewide: kzalloc() -> kcalloc()Kees Cook
The kzalloc() function has a 2-factor argument form, kcalloc(). This patch replaces cases of: kzalloc(a * b, gfp) with: kcalloc(a * b, gfp) as well as handling cases of: kzalloc(a * b * c, gfp) with: kzalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kzalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kzalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kzalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kzalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kzalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(char) * COUNT + COUNT , ...) | kzalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kzalloc + kcalloc ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kzalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kzalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kzalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kzalloc(C1 * C2 * C3, ...) | kzalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kzalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kzalloc(sizeof(THING) * C2, ...) | kzalloc(sizeof(TYPE) * C2, ...) | kzalloc(C1 * C2 * C3, ...) | kzalloc(C1 * C2, ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - (E1) * E2 + E1, E2 , ...) | - kzalloc + kcalloc ( - (E1) * (E2) + E1, E2 , ...) | - kzalloc + kcalloc ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-05-26switch the rest of procfs lookups to d_splice_alias()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-04-11fs/proc/proc_sysctl.c: fix typo in sysctl_check_table_array()Waiman Long
Patch series "ipc: Clamp *mni to the real IPCMNI limit", v3. The sysctl parameters msgmni, shmmni and semmni have an inherent limit of IPC_MNI (32k). However, users may not be aware of that because they can write a value much higher than that without getting any error or notification. Reading the parameters back will show the newly written values which are not real. Enforcing the limit by failing sysctl parameter write, however, can break existing user applications. To address this delemma, a new flags field is introduced into the ctl_table. The value CTL_FLAGS_CLAMP_RANGE can be added to any ctl_table entries to enable a looser range clamping without returning any error. For example, .flags = CTL_FLAGS_CLAMP_RANGE, This flags value are now used for the range checking of shmmni, msgmni and semmni without breaking existing applications. If any out of range value is written to those sysctl parameters, the following warning will be printed instead. Kernel parameter "shmmni" was set out of range [0, 32768], clamped to 32768. Reading the values back will show 32768 instead of some fake values. This patch (of 6): Fix a typo. Link: http://lkml.kernel.org/r/1519926220-7453-2-git-send-email-longman@redhat.com Signed-off-by: Waiman Long <longman@redhat.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Luis R. Rodriguez <mcgrof@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Matthew Wilcox <willy@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11fs/proc/proc_sysctl.c: remove redundant link check in proc_sys_link_fill_cache()Danilo Krummrich
proc_sys_link_fill_cache() does not need to check whether we're called for a link - it's already done by scan(). Link: http://lkml.kernel.org/r/20180228013506.4915-2-danilokrummrich@dk-develop.de Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "Luis R . Rodriguez" <mcgrof@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11fs/proc/proc_sysctl.c: fix potential page fault while unregistering sysctl tableDanilo Krummrich
proc_sys_link_fill_cache() does not take currently unregistering sysctl tables into account, which might result into a page fault in sysctl_follow_link() - add a check to fix it. This bug has been present since v3.4. Link: http://lkml.kernel.org/r/20180228013506.4915-1-danilokrummrich@dk-develop.de Fixes: 0e47c99d7fe25 ("sysctl: Replace root_list with links between sysctl_table_sets") Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: "Luis R . Rodriguez" <mcgrof@kernel.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds
This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-27fs: annotate ->poll() instancesAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-13Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge yet more updates from Andrew Morton: - various misc things - kexec updates - sysctl core updates - scripts/gdb udpates - checkpoint-restart updates - ipc updates - kernel/watchdog updates - Kees's "rough equivalent to the glibc _FORTIFY_SOURCE=1 feature" - "stackprotector: ascii armor the stack canary" - more MM bits - checkpatch updates * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (96 commits) writeback: rework wb_[dec|inc]_stat family of functions ARM: samsung: usb-ohci: move inline before return type video: fbdev: omap: move inline before return type video: fbdev: intelfb: move inline before return type USB: serial: safe_serial: move __inline__ before return type drivers: tty: serial: move inline before return type drivers: s390: move static and inline before return type x86/efi: move asmlinkage before return type sh: move inline before return type MIPS: SMP: move asmlinkage before return type m68k: coldfire: move inline before return type ia64: sn: pci: move inline before type ia64: move inline before return type FRV: tlbflush: move asmlinkage before return type CRIS: gpio: move inline before return type ARM: HP Jornada 7XX: move inline before return type ARM: KVM: move asmlinkage before type checkpatch: improve the STORAGE_CLASS test mm, migration: do not trigger OOM killer when migrating memory drm/i915: use __GFP_RETRY_MAYFAIL ...
2017-07-12sysctl: add unsigned int range supportLuis R. Rodriguez
To keep parity with regular int interfaces provide the an unsigned int proc_douintvec_minmax() which allows you to specify a range of allowed valid numbers. Adding proc_douintvec_minmax_sysadmin() is easy but we can wait for an actual user for that. Link: http://lkml.kernel.org/r/20170519033554.18592-6-mcgrof@kernel.org Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Kees Cook <keescook@chromium.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12sysctl: simplify unsigned int supportLuis R. Rodriguez
Commit e7d316a02f68 ("sysctl: handle error writing UINT_MAX to u32 fields") added proc_douintvec() to start help adding support for unsigned int, this however was only half the work needed. Two fixes have come in since then for the following issues: o Printing the values shows a negative value, this happens since do_proc_dointvec() and this uses proc_put_long() This was fixed by commit 5380e5644afbba9 ("sysctl: don't print negative flag for proc_douintvec"). o We can easily wrap around the int values: UINT_MAX is 4294967295, if we echo in 4294967295 + 1 we end up with 0, using 4294967295 + 2 we end up with 1. o We echo negative values in and they are accepted This was fixed by commit 425fffd886ba ("sysctl: report EINVAL if value is larger than UINT_MAX for proc_douintvec"). It still also failed to be added to sysctl_check_table()... instead of adding it with the current implementation just provide a proper and simplified unsigned int support without any array unsigned int support with no negative support at all. Historically sysctl proc helpers have supported arrays, due to the complexity this adds though we've taken a step back to evaluate array users to determine if its worth upkeeping for unsigned int. An evaluation using Coccinelle has been done to perform a grammatical search to ask ourselves: o How many sysctl proc_dointvec() (int) users exist which likely should be moved over to proc_douintvec() (unsigned int) ? Answer: about 8 - Of these how many are array users ? Answer: Probably only 1 o How many sysctl array users exist ? Answer: about 12 This last question gives us an idea just how popular arrays: they are not. Array support should probably just be kept for strings. The identified uint ports are: drivers/infiniband/core/ucma.c - max_backlog drivers/infiniband/core/iwcm.c - default_backlog net/core/sysctl_net_core.c - rps_sock_flow_sysctl() net/netfilter/nf_conntrack_timestamp.c - nf_conntrack_timestamp -- bool net/netfilter/nf_conntrack_acct.c nf_conntrack_acct -- bool net/netfilter/nf_conntrack_ecache.c - nf_conntrack_events -- bool net/netfilter/nf_conntrack_helper.c - nf_conntrack_helper -- bool net/phonet/sysctl.c proc_local_port_range() The only possible array users is proc_local_port_range() but it does not seem worth it to add array support just for this given the range support works just as well. Unsigned int support should be desirable more for when you *need* more than INT_MAX or using int min/max support then does not suffice for your ranges. If you forget and by mistake happen to register an unsigned int proc entry with an array, the driver will fail and you will get something as follows: sysctl table check failed: debug/test_sysctl//uint_0002 array now allowed CPU: 2 PID: 1342 Comm: modprobe Tainted: G W E <etc> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS <etc> Call Trace: dump_stack+0x63/0x81 __register_sysctl_table+0x350/0x650 ? kmem_cache_alloc_trace+0x107/0x240 __register_sysctl_paths+0x1b3/0x1e0 ? 0xffffffffc005f000 register_sysctl_table+0x1f/0x30 test_sysctl_init+0x10/0x1000 [test_sysctl] do_one_initcall+0x52/0x1a0 ? kmem_cache_alloc_trace+0x107/0x240 do_init_module+0x5f/0x200 load_module+0x1867/0x1bd0 ? __symbol_put+0x60/0x60 SYSC_finit_module+0xdf/0x110 SyS_finit_module+0xe/0x10 entry_SYSCALL_64_fastpath+0x1e/0xad RIP: 0033:0x7f042b22d119 <etc> Fixes: e7d316a02f68 ("sysctl: handle error writing UINT_MAX to u32 fields") Link: http://lkml.kernel.org/r/20170519033554.18592-5-mcgrof@kernel.org Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Suggested-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> Cc: Liping Zhang <zlpnobody@gmail.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Kees Cook <keescook@chromium.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12sysctl: fix lax sysctl_check_table() sanity checkLuis R. Rodriguez
Patch series "sysctl: few fixes", v5. I've been working on making kmod more deterministic, and as I did that I couldn't help but notice a few issues with sysctl. My end goal was just to fix unsigned int support, which back then was completely broken. Liping Zhang has sent up small atomic fixes, however it still missed yet one more fix and Alexey Dobriyan had also suggested to just drop array support given its complexity. I have inspected array support using Coccinelle and indeed its not that popular, so if in fact we can avoid it for new interfaces, I agree its best. I did develop a sysctl stress driver but will hold that off for another series. This patch (of 5): Commit 7c60c48f58a7 ("sysctl: Improve the sysctl sanity checks") improved sanity checks considerbly, however the enhancements on sysctl_check_table() meant adding a functional change so that only the last table entry's sanity error is propagated. It also changed the way errors were propagated so that each new check reset the err value, this means only last sanity check computed is used for an error. This has been in the kernel since v3.4 days. Fix this by carrying on errors from previous checks and iterations as we traverse the table and ensuring we keep any error from previous checks. We keep iterating on the table even if an error is found so we can complain for all errors found in one shot. This works as -EINVAL is always returned on error anyway, and the check for error is any non-zero value. Fixes: 7c60c48f58a7 ("sysctl: Improve the sysctl sanity checks") Link: http://lkml.kernel.org/r/20170519033554.18592-2-mcgrof@kernel.org Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-11proc: Fix proc_sys_prune_dcache to hold a sb referenceEric W. Biederman
Andrei Vagin writes: FYI: This bug has been reproduced on 4.11.7 > BUG: Dentry ffff895a3dd01240{i=4e7c09a,n=lo} still in use (1) [unmount of proc proc] > ------------[ cut here ]------------ > WARNING: CPU: 1 PID: 13588 at fs/dcache.c:1445 umount_check+0x6e/0x80 > CPU: 1 PID: 13588 Comm: kworker/1:1 Not tainted 4.11.7-200.fc25.x86_64 #1 > Hardware name: CompuLab sbc-flt1/fitlet, BIOS SBCFLT_0.08.04 06/27/2015 > Workqueue: events proc_cleanup_work > Call Trace: > dump_stack+0x63/0x86 > __warn+0xcb/0xf0 > warn_slowpath_null+0x1d/0x20 > umount_check+0x6e/0x80 > d_walk+0xc6/0x270 > ? dentry_free+0x80/0x80 > do_one_tree+0x26/0x40 > shrink_dcache_for_umount+0x2d/0x90 > generic_shutdown_super+0x1f/0xf0 > kill_anon_super+0x12/0x20 > proc_kill_sb+0x40/0x50 > deactivate_locked_super+0x43/0x70 > deactivate_super+0x5a/0x60 > cleanup_mnt+0x3f/0x90 > mntput_no_expire+0x13b/0x190 > kern_unmount+0x3e/0x50 > pid_ns_release_proc+0x15/0x20 > proc_cleanup_work+0x15/0x20 > process_one_work+0x197/0x450 > worker_thread+0x4e/0x4a0 > kthread+0x109/0x140 > ? process_one_work+0x450/0x450 > ? kthread_park+0x90/0x90 > ret_from_fork+0x2c/0x40 > ---[ end trace e1c109611e5d0b41 ]--- > VFS: Busy inodes after unmount of proc. Self-destruct in 5 seconds. Have a nice day... > BUG: unable to handle kernel NULL pointer dereference at (null) > IP: _raw_spin_lock+0xc/0x30 > PGD 0 Fix this by taking a reference to the super block in proc_sys_prune_dcache. The superblock reference is the core of the fix however the sysctl_inodes list is converted to a hlist so that hlist_del_init_rcu may be used. This allows proc_sys_prune_dache to remove inodes the sysctl_inodes list, while not causing problems for proc_sys_evict_inode when if it later choses to remove the inode from the sysctl_inodes list. Removing inodes from the sysctl_inodes list allows proc_sys_prune_dcache to have a progress guarantee, while still being able to drop all locks. The fact that head->unregistering is set in start_unregistering ensures that no more inodes will be added to the the sysctl_inodes list. Previously the code did a dance where it delayed calling iput until the next entry in the list was being considered to ensure the inode remained on the sysctl_inodes list until the next entry was walked to. The structure of the loop in this patch does not need that so is much easier to understand and maintain. Cc: stable@vger.kernel.org Reported-by: Andrei Vagin <avagin@gmail.com> Tested-by: Andrei Vagin <avagin@openvz.org> Fixes: ace0c791e6c3 ("proc/sysctl: Don't grab i_lock under sysctl_lock.") Fixes: d6cffbbe9a7e ("proc/sysctl: prune stale dentries during unregistering") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-05-05Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "This is a set of small fixes that were mostly stumbled over during more significant development. This proc fix and the fix to posix-timers are the most significant of the lot. There is a lot of good development going on but unfortunately it didn't quite make the merge window" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc: Fix unbalanced hard link numbers signal: Make kill_proc_info static rlimit: Properly call security_task_setrlimit signal: Remove unused definition of sig_user_definied ia64: Remove unused IA64_TASK_SIGHAND_OFFSET and IA64_SIGHAND_SIGLOCK_OFFSET ipc: Remove unused declaration of recompute_msgmni posix-timers: Correct sanity check in posix_cpu_nsleep sysctl: Remove dead register_sysctl_root
2017-04-16sysctl: Remove dead register_sysctl_rootEric W. Biederman
The function no longer does anything. The is only a single caller of register_sysctl_root when semantically there should be two. Remove this function so that if someone decides this functionality is needed again it will be obvious all of the callers of setup_sysctl_set need to be audited and modified appropriately. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-04-07sysctl: add sanity check for proc_douintvecLiping Zhang
Commit e7d316a02f68 ("sysctl: handle error writing UINT_MAX to u32 fields") introduced the proc_douintvec helper function, but it forgot to add the related sanity check when doing register_sysctl_table. So add it now. Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-03Merge branch 'rebased-statx' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs 'statx()' update from Al Viro. This adds the new extended stat() interface that internally subsumes our previous stat interfaces, and allows user mode to specify in more detail what kind of information it wants. It also allows for some explicit synchronization information to be passed to the filesystem, which can be relevant for network filesystems: is the cached value ok, or do you need open/close consistency, or what? From David Howells. Andreas Dilger points out that the first version of the extended statx interface was posted June 29, 2010: https://www.spinics.net/lists/linux-fsdevel/msg33831.html * 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: statx: Add a system call to make enhanced file info available
2017-03-02statx: Add a system call to make enhanced file info availableDavid Howells
Add a system call to make extended file information available, including file creation and some attribute flags where available through the underlying filesystem. The getattr inode operation is altered to take two additional arguments: a u32 request_mask and an unsigned int flags that indicate the synchronisation mode. This change is propagated to the vfs_getattr*() function. Functions like vfs_stat() are now inline wrappers around new functions vfs_statx() and vfs_statx_fd() to reduce stack usage. ======== OVERVIEW ======== The idea was initially proposed as a set of xattrs that could be retrieved with getxattr(), but the general preference proved to be for a new syscall with an extended stat structure. A number of requests were gathered for features to be included. The following have been included: (1) Make the fields a consistent size on all arches and make them large. (2) Spare space, request flags and information flags are provided for future expansion. (3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an __s64). (4) Creation time: The SMB protocol carries the creation time, which could be exported by Samba, which will in turn help CIFS make use of FS-Cache as that can be used for coherency data (stx_btime). This is also specified in NFSv4 as a recommended attribute and could be exported by NFSD [Steve French]. (5) Lightweight stat: Ask for just those details of interest, and allow a netfs (such as NFS) to approximate anything not of interest, possibly without going to the server [Trond Myklebust, Ulrich Drepper, Andreas Dilger] (AT_STATX_DONT_SYNC). (6) Heavyweight stat: Force a netfs to go to the server, even if it thinks its cached attributes are up to date [Trond Myklebust] (AT_STATX_FORCE_SYNC). And the following have been left out for future extension: (7) Data version number: Could be used by userspace NFS servers [Aneesh Kumar]. Can also be used to modify fill_post_wcc() in NFSD which retrieves i_version directly, but has just called vfs_getattr(). It could get it from the kstat struct if it used vfs_xgetattr() instead. (There's disagreement on the exact semantics of a single field, since not all filesystems do this the same way). (8) BSD stat compatibility: Including more fields from the BSD stat such as creation time (st_btime) and inode generation number (st_gen) [Jeremy Allison, Bernd Schubert]. (9) Inode generation number: Useful for FUSE and userspace NFS servers [Bernd Schubert]. (This was asked for but later deemed unnecessary with the open-by-handle capability available and caused disagreement as to whether it's a security hole or not). (10) Extra coherency data may be useful in making backups [Andreas Dilger]. (No particular data were offered, but things like last backup timestamp, the data version number and the DOS archive bit would come into this category). (11) Allow the filesystem to indicate what it can/cannot provide: A filesystem can now say it doesn't support a standard stat feature if that isn't available, so if, for instance, inode numbers or UIDs don't exist or are fabricated locally... (This requires a separate system call - I have an fsinfo() call idea for this). (12) Store a 16-byte volume ID in the superblock that can be returned in struct xstat [Steve French]. (Deferred to fsinfo). (13) Include granularity fields in the time data to indicate the granularity of each of the times (NFSv4 time_delta) [Steve French]. (Deferred to fsinfo). (14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags. Note that the Linux IOC flags are a mess and filesystems such as Ext4 define flags that aren't in linux/fs.h, so translation in the kernel may be a necessity (or, possibly, we provide the filesystem type too). (Some attributes are made available in stx_attributes, but the general feeling was that the IOC flags were to ext[234]-specific and shouldn't be exposed through statx this way). (15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer, Michael Kerrisk]. (Deferred, probably to fsinfo. Finding out if there's an ACL or seclabal might require extra filesystem operations). (16) Femtosecond-resolution timestamps [Dave Chinner]. (A __reserved field has been left in the statx_timestamp struct for this - if there proves to be a need). (17) A set multiple attributes syscall to go with this. =============== NEW SYSTEM CALL =============== The new system call is: int ret = statx(int dfd, const char *filename, unsigned int flags, unsigned int mask, struct statx *buffer); The dfd, filename and flags parameters indicate the file to query, in a similar way to fstatat(). There is no equivalent of lstat() as that can be emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is also no equivalent of fstat() as that can be emulated by passing a NULL filename to statx() with the fd of interest in dfd. Whether or not statx() synchronises the attributes with the backing store can be controlled by OR'ing a value into the flags argument (this typically only affects network filesystems): (1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this respect. (2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise its attributes with the server - which might require data writeback to occur to get the timestamps correct. (3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a network filesystem. The resulting values should be considered approximate. mask is a bitmask indicating the fields in struct statx that are of interest to the caller. The user should set this to STATX_BASIC_STATS to get the basic set returned by stat(). It should be noted that asking for more information may entail extra I/O operations. buffer points to the destination for the data. This must be 256 bytes in size. ====================== MAIN ATTRIBUTES RECORD ====================== The following structures are defined in which to return the main attribute set: struct statx_timestamp { __s64 tv_sec; __s32 tv_nsec; __s32 __reserved; }; struct statx { __u32 stx_mask; __u32 stx_blksize; __u64 stx_attributes; __u32 stx_nlink; __u32 stx_uid; __u32 stx_gid; __u16 stx_mode; __u16 __spare0[1]; __u64 stx_ino; __u64 stx_size; __u64 stx_blocks; __u64 __spare1[1]; struct statx_timestamp stx_atime; struct statx_timestamp stx_btime; struct statx_timestamp stx_ctime; struct statx_timestamp stx_mtime; __u32 stx_rdev_major; __u32 stx_rdev_minor; __u32 stx_dev_major; __u32 stx_dev_minor; __u64 __spare2[14]; }; The defined bits in request_mask and stx_mask are: STATX_TYPE Want/got stx_mode & S_IFMT STATX_MODE Want/got stx_mode & ~S_IFMT STATX_NLINK Want/got stx_nlink STATX_UID Want/got stx_uid STATX_GID Want/got stx_gid STATX_ATIME Want/got stx_atime{,_ns} STATX_MTIME Want/got stx_mtime{,_ns} STATX_CTIME Want/got stx_ctime{,_ns} STATX_INO Want/got stx_ino STATX_SIZE Want/got stx_size STATX_BLOCKS Want/got stx_blocks STATX_BASIC_STATS [The stuff in the normal stat struct] STATX_BTIME Want/got stx_btime{,_ns} STATX_ALL [All currently available stuff] stx_btime is the file creation time, stx_mask is a bitmask indicating the data provided and __spares*[] are where as-yet undefined fields can be placed. Time fields are structures with separate seconds and nanoseconds fields plus a reserved field in case we want to add even finer resolution. Note that times will be negative if before 1970; in such a case, the nanosecond fields will also be negative if not zero. The bits defined in the stx_attributes field convey information about a file, how it is accessed, where it is and what it does. The following attributes map to FS_*_FL flags and are the same numerical value: STATX_ATTR_COMPRESSED File is compressed by the fs STATX_ATTR_IMMUTABLE File is marked immutable STATX_ATTR_APPEND File is append-only STATX_ATTR_NODUMP File is not to be dumped STATX_ATTR_ENCRYPTED File requires key to decrypt in fs Within the kernel, the supported flags are listed by: KSTAT_ATTR_FS_IOC_FLAGS [Are any other IOC flags of sufficient general interest to be exposed through this interface?] New flags include: STATX_ATTR_AUTOMOUNT Object is an automount trigger These are for the use of GUI tools that might want to mark files specially, depending on what they are. Fields in struct statx come in a number of classes: (0) stx_dev_*, stx_blksize. These are local system information and are always available. (1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino, stx_size, stx_blocks. These will be returned whether the caller asks for them or not. The corresponding bits in stx_mask will be set to indicate whether they actually have valid values. If the caller didn't ask for them, then they may be approximated. For example, NFS won't waste any time updating them from the server, unless as a byproduct of updating something requested. If the values don't actually exist for the underlying object (such as UID or GID on a DOS file), then the bit won't be set in the stx_mask, even if the caller asked for the value. In such a case, the returned value will be a fabrication. Note that there are instances where the type might not be valid, for instance Windows reparse points. (2) stx_rdev_*. This will be set only if stx_mode indicates we're looking at a blockdev or a chardev, otherwise will be 0. (3) stx_btime. Similar to (1), except this will be set to 0 if it doesn't exist. ======= TESTING ======= The following test program can be used to test the statx system call: samples/statx/test-statx.c Just compile and run, passing it paths to the files you want to examine. The file is built automatically if CONFIG_SAMPLES is enabled. Here's some example output. Firstly, an NFS directory that crosses to another FSID. Note that the AUTOMOUNT attribute is set because transiting this directory will cause d_automount to be invoked by the VFS. [root@andromeda ~]# /tmp/test-statx -A /warthog/data statx(/warthog/data) = 0 results=7ff Size: 4096 Blocks: 8 IO Block: 1048576 directory Device: 00:26 Inode: 1703937 Links: 125 Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041 Access: 2016-11-24 09:02:12.219699527+0000 Modify: 2016-11-17 10:44:36.225653653+0000 Change: 2016-11-17 10:44:36.225653653+0000 Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------) Secondly, the result of automounting on that directory. [root@andromeda ~]# /tmp/test-statx /warthog/data statx(/warthog/data) = 0 results=7ff Size: 4096 Blocks: 8 IO Block: 1048576 directory Device: 00:27 Inode: 2 Links: 125 Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041 Access: 2016-11-24 09:02:12.219699527+0000 Modify: 2016-11-17 10:44:36.225653653+0000 Change: 2016-11-17 10:44:36.225653653+0000 Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-02sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h>Ingo Molnar
Add #include <linux/cred.h> dependencies to all .c files rely on sched.h doing that for them. Note that even if the count where we need to add extra headers seems high, it's still a net win, because <linux/sched.h> is included in over 2,200 files ... Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-22proc/sysctl: Don't grab i_lock under sysctl_lock.Eric W. Biederman
Konstantin Khlebnikov <khlebnikov@yandex-team.ru> writes: > This patch has locking problem. I've got lockdep splat under LTP. > > [ 6633.115456] ====================================================== > [ 6633.115502] [ INFO: possible circular locking dependency detected ] > [ 6633.115553] 4.9.10-debug+ #9 Tainted: G L > [ 6633.115584] ------------------------------------------------------- > [ 6633.115627] ksm02/284980 is trying to acquire lock: > [ 6633.115659] (&sb->s_type->i_lock_key#4){+.+...}, at: [<ffffffff816bc1ce>] igrab+0x1e/0x80 > [ 6633.115834] but task is already holding lock: > [ 6633.115882] (sysctl_lock){+.+...}, at: [<ffffffff817e379b>] unregister_sysctl_table+0x6b/0x110 > [ 6633.116026] which lock already depends on the new lock. > [ 6633.116026] > [ 6633.116080] > [ 6633.116080] the existing dependency chain (in reverse order) is: > [ 6633.116117] > -> #2 (sysctl_lock){+.+...}: > -> #1 (&(&dentry->d_lockref.lock)->rlock){+.+...}: > -> #0 (&sb->s_type->i_lock_key#4){+.+...}: > > d_lock nests inside i_lock > sysctl_lock nests inside d_lock in d_compare > > This patch adds i_lock nesting inside sysctl_lock. Al Viro <viro@ZenIV.linux.org.uk> replied: > Once ->unregistering is set, you can drop sysctl_lock just fine. So I'd > try something like this - use rcu_read_lock() in proc_sys_prune_dcache(), > drop sysctl_lock() before it and regain after. Make sure that no inodes > are added to the list ones ->unregistering has been set and use RCU list > primitives for modifying the inode list, with sysctl_lock still used to > serialize its modifications. > > Freeing struct inode is RCU-delayed (see proc_destroy_inode()), so doing > igrab() is safe there. Since we don't drop inode reference until after we'd > passed beyond it in the list, list_for_each_entry_rcu() should be fine. I agree with Al Viro's analsysis of the situtation. Fixes: d6cffbbe9a7e ("proc/sysctl: prune stale dentries during unregistering") Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Tested-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Suggested-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-02-13proc/sysctl: prune stale dentries during unregisteringKonstantin Khlebnikov
Currently unregistering sysctl table does not prune its dentries. Stale dentries could slowdown sysctl operations significantly. For example, command: # for i in {1..100000} ; do unshare -n -- sysctl -a &> /dev/null ; done creates a millions of stale denties around sysctls of loopback interface: # sysctl fs.dentry-state fs.dentry-state = 25812579 24724135 45 0 0 0 All of them have matching names thus lookup have to scan though whole hash chain and call d_compare (proc_sys_compare) which checks them under system-wide spinlock (sysctl_lock). # time sysctl -a > /dev/null real 1m12.806s user 0m0.016s sys 1m12.400s Currently only memory reclaimer could remove this garbage. But without significant memory pressure this never happens. This patch collects sysctl inodes into list on sysctl table header and prunes all their dentries once that table unregisters. Konstantin Khlebnikov <khlebnikov@yandex-team.ru> writes: > On 10.02.2017 10:47, Al Viro wrote: >> how about >> the matching stats *after* that patch? > > dcache size doesn't grow endlessly, so stats are fine > > # sysctl fs.dentry-state > fs.dentry-state = 92712 58376 45 0 0 0 > > # time sysctl -a &>/dev/null > > real 0m0.013s > user 0m0.004s > sys 0m0.008s Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2017-01-10sysctl: Drop reference added by grab_header in proc_sys_readdirZhou Chengming
Fixes CVE-2016-9191, proc_sys_readdir doesn't drop reference added by grab_header when return from !dir_emit_dots path. It can cause any path called unregister_sysctl_table will wait forever. The calltrace of CVE-2016-9191: [ 5535.960522] Call Trace: [ 5535.963265] [<ffffffff817cdaaf>] schedule+0x3f/0xa0 [ 5535.968817] [<ffffffff817d33fb>] schedule_timeout+0x3db/0x6f0 [ 5535.975346] [<ffffffff817cf055>] ? wait_for_completion+0x45/0x130 [ 5535.982256] [<ffffffff817cf0d3>] wait_for_completion+0xc3/0x130 [ 5535.988972] [<ffffffff810d1fd0>] ? wake_up_q+0x80/0x80 [ 5535.994804] [<ffffffff8130de64>] drop_sysctl_table+0xc4/0xe0 [ 5536.001227] [<ffffffff8130de17>] drop_sysctl_table+0x77/0xe0 [ 5536.007648] [<ffffffff8130decd>] unregister_sysctl_table+0x4d/0xa0 [ 5536.014654] [<ffffffff8130deff>] unregister_sysctl_table+0x7f/0xa0 [ 5536.021657] [<ffffffff810f57f5>] unregister_sched_domain_sysctl+0x15/0x40 [ 5536.029344] [<ffffffff810d7704>] partition_sched_domains+0x44/0x450 [ 5536.036447] [<ffffffff817d0761>] ? __mutex_unlock_slowpath+0x111/0x1f0 [ 5536.043844] [<ffffffff81167684>] rebuild_sched_domains_locked+0x64/0xb0 [ 5536.051336] [<ffffffff8116789d>] update_flag+0x11d/0x210 [ 5536.057373] [<ffffffff817cf61f>] ? mutex_lock_nested+0x2df/0x450 [ 5536.064186] [<ffffffff81167acb>] ? cpuset_css_offline+0x1b/0x60 [ 5536.070899] [<ffffffff810fce3d>] ? trace_hardirqs_on+0xd/0x10 [ 5536.077420] [<ffffffff817cf61f>] ? mutex_lock_nested+0x2df/0x450 [ 5536.084234] [<ffffffff8115a9f5>] ? css_killed_work_fn+0x25/0x220 [ 5536.091049] [<ffffffff81167ae5>] cpuset_css_offline+0x35/0x60 [ 5536.097571] [<ffffffff8115aa2c>] css_killed_work_fn+0x5c/0x220 [ 5536.104207] [<ffffffff810bc83f>] process_one_work+0x1df/0x710 [ 5536.110736] [<ffffffff810bc7c0>] ? process_one_work+0x160/0x710 [ 5536.117461] [<ffffffff810bce9b>] worker_thread+0x12b/0x4a0 [ 5536.123697] [<ffffffff810bcd70>] ? process_one_work+0x710/0x710 [ 5536.130426] [<ffffffff810c3f7e>] kthread+0xfe/0x120 [ 5536.135991] [<ffffffff817d4baf>] ret_from_fork+0x1f/0x40 [ 5536.142041] [<ffffffff810c3e80>] ? kthread_create_on_node+0x230/0x230 One cgroup maintainer mentioned that "cgroup is trying to offline a cpuset css, which takes place under cgroup_mutex. The offlining ends up trying to drain active usages of a sysctl table which apprently is not happening." The real reason is that proc_sys_readdir doesn't drop reference added by grab_header when return from !dir_emit_dots path. So this cpuset offline path will wait here forever. See here for details: http://www.openwall.com/lists/oss-security/2016/11/04/13 Fixes: f0c3b5093add ("[readdir] convert procfs") Cc: stable@vger.kernel.org Reported-by: CAI Qian <caiqian@redhat.com> Tested-by: Yang Shukui <yangshukui@huawei.com> Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com> Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2016-10-10Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: ">rename2() work from Miklos + current_time() from Deepa" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Replace current_fs_time() with current_time() fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps fs: Replace CURRENT_TIME with current_time() for inode timestamps fs: proc: Delete inode time initializations in proc_alloc_inode() vfs: Add current_time() api vfs: add note about i_op->rename changes to porting fs: rename "rename2" i_op to "rename" vfs: remove unused i_op->rename fs: make remaining filesystems use .rename2 libfs: support RENAME_NOREPLACE in simple_rename() fs: support RENAME_NOREPLACE for local filesystems ncpfs: fix unused variable warning
2016-10-10Merge branch 'work.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "Assorted misc bits and pieces. There are several single-topic branches left after this (rename2 series from Miklos, current_time series from Deepa Dinamani, xattr series from Andreas, uaccess stuff from from me) and I'd prefer to send those separately" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits) proc: switch auxv to use of __mem_open() hpfs: support FIEMAP cifs: get rid of unused arguments of CIFSSMBWrite() posix_acl: uapi header split posix_acl: xattr representation cleanups fs/aio.c: eliminate redundant loads in put_aio_ring_file fs/internal.h: add const to ns_dentry_operations declaration compat: remove compat_printk() fs/buffer.c: make __getblk_slow() static proc: unsigned file descriptors fs/file: more unsigned file descriptors fs: compat: remove redundant check of nr_segs cachefiles: Fix attempt to read i_blocks after deleting file [ver #2] cifs: don't use memcpy() to copy struct iov_iter get rid of separate multipage fault-in primitives fs: Avoid premature clearing of capabilities fs: Give dentry to inode_change_ok() instead of inode fuse: Propagate dentry down to inode_change_ok() ceph: Propagate dentry down to inode_change_ok() xfs: Propagate dentry down to inode_change_ok() ...
2016-10-06Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "This set of changes is a number of smaller things that have been overlooked in other development cycles focused on more fundamental change. The devpts changes are small things that were a distraction until we managed to kill off DEVPTS_MULTPLE_INSTANCES. There is an trivial regression fix to autofs for the unprivileged mount changes that went in last cycle. A pair of ioctls has been added by Andrey Vagin making it is possible to discover the relationships between namespaces when referring to them through file descriptors. The big user visible change is starting to add simple resource limits to catch programs that misbehave. With namespaces in general and user namespaces in particular allowing users to use more kinds of resources, it has become important to have something to limit errant programs. Because the purpose of these limits is to catch errant programs the code needs to be inexpensive to use as it always on, and the default limits need to be high enough that well behaved programs on well behaved systems don't encounter them. To this end, after some review I have implemented per user per user namespace limits, and use them to limit the number of namespaces. The limits being per user mean that one user can not exhause the limits of another user. The limits being per user namespace allow contexts where the limit is 0 and security conscious folks can remove from their threat anlysis the code used to manage namespaces (as they have historically done as it root only). At the same time the limits being per user namespace allow other parts of the system to use namespaces. Namespaces are increasingly being used in application sand boxing scenarios so an all or nothing disable for the entire system for the security conscious folks makes increasing use of these sandboxes impossible. There is also added a limit on the maximum number of mounts present in a single mount namespace. It is nontrivial to guess what a reasonable system wide limit on the number of mount structure in the kernel would be, especially as it various based on how a system is using containers. A limit on the number of mounts in a mount namespace however is much easier to understand and set. In most cases in practice only about 1000 mounts are used. Given that some autofs scenarious have the potential to be 30,000 to 50,000 mounts I have set the default limit for the number of mounts at 100,000 which is well above every known set of users but low enough that the mount hash tables don't degrade unreaonsably. These limits are a start. I expect this estabilishes a pattern that other limits for resources that namespaces use will follow. There has been interest in making inotify event limits per user per user namespace as well as interest expressed in making details about what is going on in the kernel more visible" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (28 commits) autofs: Fix automounts by using current_real_cred()->uid mnt: Add a per mount namespace limit on the number of mounts netns: move {inc,dec}_net_namespaces into #ifdef nsfs: Simplify __ns_get_path tools/testing: add a test to check nsfs ioctl-s nsfs: add ioctl to get a parent namespace nsfs: add ioctl to get an owning user namespace for ns file descriptor kernel: add a helper to get an owning user namespace for a namespace devpts: Change the owner of /dev/pts/ptmx to the mounter of /dev/pts devpts: Remove sync_filesystems devpts: Make devpts_kill_sb safe if fsi is NULL devpts: Simplify devpts_mount by using mount_nodev devpts: Move the creation of /dev/pts/ptmx into fill_super devpts: Move parse_mount_options into fill_super userns: When the per user per user namespace limit is reached return ENOSPC userns; Document per user per user namespace limits. mntns: Add a limit on the number of mount namespaces. netns: Add a limit on the number of net namespaces cgroupns: Add a limit on the number of cgroup namespaces ipcns: Add a limit on the number of ipc namespaces ...
2016-09-27fs: Replace CURRENT_TIME with current_time() for inode timestampsDeepa Dinamani
CURRENT_TIME macro is not appropriate for filesystems as it doesn't use the right granularity for filesystem timestamps. Use current_time() instead. CURRENT_TIME is also not y2038 safe. This is also in preparation for the patch that transitions vfs timestamps to use 64 bit time and hence make them y2038 safe. As part of the effort current_time() will be extended to do range checks. Hence, it is necessary for all file system timestamps to use current_time(). Also, current_time() will be transitioned along with vfs to be y2038 safe. Note that whenever a single call to current_time() is used to change timestamps in different inodes, it is because they share the same time granularity. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Felipe Balbi <balbi@kernel.org> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: David Sterba <dsterba@suse.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-22fs: Give dentry to inode_change_ok() instead of inodeJan Kara
inode_change_ok() will be resposible for clearing capabilities and IMA extended attributes and as such will need dentry. Give it as an argument to inode_change_ok() instead of an inode. Also rename inode_change_ok() to setattr_prepare() to better relect that it does also some modifications in addition to checks. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2016-08-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Minor overlapping changes for both merge conflicts. Resolution work done by Stephen Rothwell was used as a reference. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-14net: make net namespace sysctls belong to container's ownerDmitry Torokhov
If net namespace is attached to a user namespace let's make container's root owner of sysctls affecting said network namespace instead of global root. This also allows us to clean up net_ctl_permissions() because we do not need to fudge permissions anymore for the container's owner since it now owns the objects in question. Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-08sysctl: Stop implicitly passing current into sysctl_table_root.lookupEric W. Biederman
Passing nsproxy into sysctl_table_root.lookup was a premature optimization in attempt to avoid depending on current. The directory /proc/self/sys has not appeared and if and when it does this code will need to be reviewed closely and reworked anyway. So remove the premature optimization. Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-08-07Merge branch 'for-linus-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: "Assorted cleanups and fixes. In the "trivial API change" department - ->d_compare() losing 'parent' argument" * 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: cachefiles: Fix race between inactivating and culling a cache object 9p: use clone_fid() 9p: fix braino introduced in "9p: new helper - v9fs_parent_fid()" vfs: make dentry_needs_remove_privs() internal vfs: remove file_needs_remove_privs() vfs: fix deadlock in file_remove_privs() on overlayfs get rid of 'parent' argument of ->d_compare() cifs, msdos, vfat, hfs+: don't bother with parent in ->d_compare() affs ->d_compare(): don't bother with ->d_inode fold _d_rehash() and __d_rehash() together fold dentry_rcuwalk_invalidate() into its only remaining caller
2016-08-06Merge branch 'work.const-qstr' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull qstr constification updates from Al Viro: "Fairly self-contained bunch - surprising lot of places passes struct qstr * as an argument when const struct qstr * would suffice; it complicates analysis for no good reason. I'd prefer to feed that separately from the assorted fixes (those are in #for-linus and with somewhat trickier topology)" * 'work.const-qstr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: qstr: constify instances in adfs qstr: constify instances in lustre qstr: constify instances in f2fs qstr: constify instances in ext2 qstr: constify instances in vfat qstr: constify instances in procfs qstr: constify instances in fuse qstr constify instances in fs/dcache.c qstr: constify instances in nfs qstr: constify instances in ocfs2 qstr: constify instances in autofs4 qstr: constify instances in hfs qstr: constify instances in hfsplus qstr: constify instances in logfs qstr: constify dentry_init_security
2016-07-31get rid of 'parent' argument of ->d_compare()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-30qstr: constify instances in procfsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-10vfs: make the string hashes salt the hashLinus Torvalds
We always mixed in the parent pointer into the dentry name hash, but we did it late at lookup time. It turns out that we can simplify that lookup-time action by salting the hash with the parent pointer early instead of late. A few other users of our string hashes also wanted to mix in their own pointers into the hash, and those are updated to use the same mechanism. Hash users that don't have any particular initial salt can just use the NULL pointer as a no-salt. Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: George Spelvin <linux@sciencehorizons.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-02switch all procfs directories ->iterate_shared()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02proc_sys_fill_cache(): switch to d_alloc_parallel()Al Viro
make it usable with directory locked shared Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-09-29fs: Drop unlikely before IS_ERR(_OR_NULL)Viresh Kumar
IS_ERR(_OR_NULL) already contain an 'unlikely' compiler flag and there is no need to do that again from its callers. Drop it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Jeff Layton <jlayton@poochiereds.net> Reviewed-by: David Howells <dhowells@redhat.com> Reviewed-by: Steve French <smfrench@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-07-01sysctl: Allow creating permanently empty directories that serve as mountpoints.Eric W. Biederman
Add a magic sysctl table sysctl_mount_point that when used to create a directory forces that directory to be permanently empty. Update the code to use make_empty_dir_inode when accessing permanently empty directories. Update the code to not allow adding to permanently empty directories. Update /proc/sys/fs/binfmt_misc to be a permanently empty directory. Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-04-15VFS: normal filesystems (and lustre): d_inode() annotationsDavid Howells
that's the bulk of filesystem drivers dealing with inodes of their own Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-08sysctl: remove typedef ctl_tableJoe Perches
Remove the final user, and the typedef itself. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>