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2020-05-27Merge commit a4ae32c71fe9 ("exec: Always set cap_ambient in cap_bprm_set_creds")Eric W. Biederman
This is a bug fix and one of two places where I have found that the result of calling security_bprm_repopulate_creds more than once on different bprm->files depends on all of the bprm->files not just the file bprm->file. I intend to fix both of those cases and then modify the code to only call security_bprm_repopulate_creds on the final bprm file. So merge this change in so I hopefully reduce conflicts for others and I make it possible to build on top of this change. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-05-27Merge branch 'for-5.7-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: - Reverted stricter synchronization for cgroup recursive stats which was prepping it for event counter usage which never got merged. The change was causing performation regressions in some cases. - Restore bpf-based device-cgroup operation even when cgroup1 device cgroup is disabled. - An out-param init fix. * 'for-5.7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: device_cgroup: Cleanup cgroup eBPF device filter code xattr: fix uninitialized out-param Revert "cgroup: Add memory barriers to plug cgroup_rstat_updated() race window"
2020-05-27Merge branch 'exec-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull execve fix from Eric Biederman: "While working on my exec cleanups I found a bug in exec that winds up miscomputing the ambient credentials during exec. Andy appears to have to been confused as to why credentials are computed for both the script and the interpreter From the original patch description: [3] Linux very confusingly processes both the script and the interpreter if applicable, for reasons that elude me. The results from thinking about a script's file capabilities and/or setuid bits are mostly discarded. The only value in struct cred that gets changed in cap_bprm_set_creds that I could find that might persist between the script and the interpreter was cap_ambient. Which is fixed with this trivial change" * 'exec-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: exec: Always set cap_ambient in cap_bprm_set_creds
2020-05-26exec: Always set cap_ambient in cap_bprm_set_credsEric W. Biederman
An invariant of cap_bprm_set_creds is that every field in the new cred structure that cap_bprm_set_creds might set, needs to be set every time to ensure the fields does not get a stale value. The field cap_ambient is not set every time cap_bprm_set_creds is called, which means that if there is a suid or sgid script with an interpreter that has neither the suid nor the sgid bits set the interpreter should be able to accept ambient credentials. Unfortuantely because cap_ambient is not reset to it's original value the interpreter can not accept ambient credentials. Given that the ambient capability set is expected to be controlled by the caller, I don't think this is particularly serious. But it is definitely worth fixing so the code works correctly. I have tested to verify my reading of the code is correct and the interpreter of a sgid can receive ambient capabilities with this change and cannot receive ambient capabilities without this change. Cc: stable@vger.kernel.org Cc: Andy Lutomirski <luto@kernel.org> Fixes: 58319057b784 ("capabilities: ambient capabilities") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-05-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
The MSCC bug fix in 'net' had to be slightly adjusted because the register accesses are done slightly differently in net-next. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds
Pull networking fixes from David Miller: 1) Fix RCU warnings in ipv6 multicast router code, from Madhuparna Bhowmik. 2) Nexthop attributes aren't being checked properly because of mis-initialized iterator, from David Ahern. 3) Revert iop_idents_reserve() change as it caused performance regressions and was just working around what is really a UBSAN bug in the compiler. From Yuqi Jin. 4) Read MAC address properly from ROM in bmac driver (double iteration proceeds past end of address array), from Jeremy Kerr. 5) Add Microsoft Surface device IDs to r8152, from Marc Payne. 6) Prevent reference to freed SKB in __netif_receive_skb_core(), from Boris Sukholitko. 7) Fix ACK discard behavior in rxrpc, from David Howells. 8) Preserve flow hash across packet scrubbing in wireguard, from Jason A. Donenfeld. 9) Cap option length properly for SO_BINDTODEVICE in AX25, from Eric Dumazet. 10) Fix encryption error checking in kTLS code, from Vadim Fedorenko. 11) Missing BPF prog ref release in flow dissector, from Jakub Sitnicki. 12) dst_cache must be used with BH disabled in tipc, from Eric Dumazet. 13) Fix use after free in mlxsw driver, from Jiri Pirko. 14) Order kTLS key destruction properly in mlx5 driver, from Tariq Toukan. 15) Check devm_platform_ioremap_resource() return value properly in several drivers, from Tiezhu Yang. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (71 commits) net: smsc911x: Fix runtime PM imbalance on error net/mlx4_core: fix a memory leak bug. net: ethernet: ti: cpsw: fix ASSERT_RTNL() warning during suspend net: phy: mscc: fix initialization of the MACsec protocol mode net: stmmac: don't attach interface until resume finishes net: Fix return value about devm_platform_ioremap_resource() net/mlx5: Fix error flow in case of function_setup failure net/mlx5e: CT: Correctly get flow rule net/mlx5e: Update netdev txq on completions during closure net/mlx5: Annotate mutex destroy for root ns net/mlx5: Don't maintain a case of del_sw_func being null net/mlx5: Fix cleaning unmanaged flow tables net/mlx5: Fix memory leak in mlx5_events_init net/mlx5e: Fix inner tirs handling net/mlx5e: kTLS, Destroy key object after destroying the TIS net/mlx5e: Fix allowed tc redirect merged eswitch offload cases net/mlx5: Avoid processing commands before cmdif is ready net/mlx5: Fix a race when moving command interface to events mode net/mlx5: Add command entry handling completion rxrpc: Fix a memory leak in rxkad_verify_response() ...
2020-05-22ima: verify mprotect change is consistent with mmap policyMimi Zohar
Files can be mmap'ed read/write and later changed to execute to circumvent IMA's mmap appraise policy rules. Due to locking issues (mmap semaphore would be taken prior to i_mutex), files can not be measured or appraised at this point. Eliminate this integrity gap, by denying the mprotect PROT_EXECUTE change, if an mmap appraise policy rule exists. On mprotect change success, return 0. On failure, return -EACESS. Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-05-21apparmor: Fix use-after-free in aa_audit_rule_initNavid Emamdoost
In the implementation of aa_audit_rule_init(), when aa_label_parse() fails the allocated memory for rule is released using aa_audit_rule_free(). But after this release, the return statement tries to access the label field of the rule which results in use-after-free. Before releasing the rule, copy errNo and return it after release. Fixes: 52e8c38001d8 ("apparmor: Fix memory leak of rule on error exit path") Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-05-21apparmor: Fix aa_label refcnt leak in policy_updateXiyu Yang
policy_update() invokes begin_current_label_crit_section(), which returns a reference of the updated aa_label object to "label" with increased refcount. When policy_update() returns, "label" becomes invalid, so the refcount should be decreased to keep refcount balanced. The reference counting issue happens in one exception handling path of policy_update(). When aa_may_manage_policy() returns not NULL, the refcnt increased by begin_current_label_crit_section() is not decreased, causing a refcnt leak. Fix this issue by jumping to "end_section" label when aa_may_manage_policy() returns not NULL. Fixes: 5ac8c355ae00 ("apparmor: allow introspecting the loaded policy pre internal transform") Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-05-21apparmor: fix potential label refcnt leak in aa_change_profileXiyu Yang
aa_change_profile() invokes aa_get_current_label(), which returns a reference of the current task's label. According to the comment of aa_get_current_label(), the returned reference must be put with aa_put_label(). However, when the original object pointed by "label" becomes unreachable because aa_change_profile() returns or a new object is assigned to "label", reference count increased by aa_get_current_label() is not decreased, causing a refcnt leak. Fix this by calling aa_put_label() before aa_change_profile() return and dropping unnecessary aa_get_current_label(). Fixes: 9fcf78cca198 ("apparmor: update domain transitions that are subsets of confinement at nnp") Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-05-21exec: Convert security_bprm_set_creds into security_bprm_repopulate_credsEric W. Biederman
Rename bprm->cap_elevated to bprm->active_secureexec and initialize it in prepare_binprm instead of in cap_bprm_set_creds. Initializing bprm->active_secureexec in prepare_binprm allows multiple implementations of security_bprm_repopulate_creds to play nicely with each other. Rename security_bprm_set_creds to security_bprm_reopulate_creds to emphasize that this path recomputes part of bprm->cred. This recomputation avoids the time of check vs time of use problems that are inherent in unix #! interpreters. In short two renames and a move in the location of initializing bprm->active_secureexec. Link: https://lkml.kernel.org/r/87o8qkzrxp.fsf_-_@x220.int.ebiederm.org Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-05-20security: Fix hook iteration for secid_to_secctxKP Singh
secid_to_secctx is not stackable, and since the BPF LSM registers this hook by default, the call_int_hook logic is not suitable which "bails-on-fail" and casues issues when other LSMs register this hook and eventually breaks Audit. In order to fix this, directly iterate over the security hooks instead of using call_int_hook as suggested in: https: //lore.kernel.org/bpf/9d0eb6c6-803a-ff3a-5603-9ad6d9edfc00@schaufler-ca.com/#t Fixes: 98e828a0650f ("security: Refactor declaration of LSM hooks") Fixes: 625236ba3832 ("security: Fix the default value of secid_to_secctx hook") Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: James Morris <jamorris@linux.microsoft.com> Link: https://lore.kernel.org/bpf/20200520125616.193765-1-kpsingh@chromium.org
2020-05-20exec: Factor security_bprm_creds_for_exec out of security_bprm_set_credsEric W. Biederman
Today security_bprm_set_creds has several implementations: apparmor_bprm_set_creds, cap_bprm_set_creds, selinux_bprm_set_creds, smack_bprm_set_creds, and tomoyo_bprm_set_creds. Except for cap_bprm_set_creds they all test bprm->called_set_creds and return immediately if it is true. The function cap_bprm_set_creds ignores bprm->calld_sed_creds entirely. Create a new LSM hook security_bprm_creds_for_exec that is called just before prepare_binprm in __do_execve_file, resulting in a LSM hook that is called exactly once for the entire of exec. Modify the bits of security_bprm_set_creds that only want to be called once per exec into security_bprm_creds_for_exec, leaving only cap_bprm_set_creds behind. Remove bprm->called_set_creds all of it's former users have been moved to security_bprm_creds_for_exec. Add or upate comments a appropriate to bring them up to date and to reflect this change. Link: https://lkml.kernel.org/r/87v9kszrzh.fsf_-_@x220.int.ebiederm.org Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> # For the LSM and Smack bits Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-05-19smack: Implement the watch_key and post_notification hooksDavid Howells
Implement the watch_key security hook in Smack to make sure that a key grants the caller Read permission in order to set a watch on a key. Also implement the post_notification security hook to make sure that the notification source is granted Write permission by the watch queue. For the moment, the watch_devices security hook is left unimplemented as it's not obvious what the object should be since the queue is global and didn't previously exist. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com>
2020-05-19selinux: Implement the watch_key security hookDavid Howells
Implement the watch_key security hook to make sure that a key grants the caller View permission in order to set a watch on a key. For the moment, the watch_devices security hook is left unimplemented as it's not obvious what the object should be since the queue is global and didn't previously exist. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Reviewed-by: James Morris <jamorris@linux.microsoft.com>
2020-05-19keys: Make the KEY_NEED_* perms an enum rather than a maskDavid Howells
Since the meaning of combining the KEY_NEED_* constants is undefined, make it so that you can't do that by turning them into an enum. The enum is also given some extra values to represent special circumstances, such as: (1) The '0' value is reserved and causes a warning to trap the parameter being unset. (2) The key is to be unlinked and we require no permissions on it, only the keyring, (this replaces the KEY_LOOKUP_FOR_UNLINK flag). (3) An override due to CAP_SYS_ADMIN. (4) An override due to an instantiation token being present. (5) The permissions check is being deferred to later key_permission() calls. The extra values give the opportunity for LSMs to audit these situations. [Note: This really needs overhauling so that lookup_user_key() tells key_task_permission() and the LSM what operation is being done and leaves it to those functions to decide how to map that onto the available permits. However, I don't really want to make these change in the middle of the notifications patchset.] Signed-off-by: David Howells <dhowells@redhat.com> cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> cc: Paul Moore <paul@paul-moore.com> cc: Stephen Smalley <stephen.smalley.work@gmail.com> cc: Casey Schaufler <casey@schaufler-ca.com> cc: keyrings@vger.kernel.org cc: selinux@vger.kernel.org
2020-05-19watch_queue: Add a key/keyring notification facilityDavid Howells
Add a key/keyring change notification facility whereby notifications about changes in key and keyring content and attributes can be received. Firstly, an event queue needs to be created: pipe2(fds, O_NOTIFICATION_PIPE); ioctl(fds[1], IOC_WATCH_QUEUE_SET_SIZE, 256); then a notification can be set up to report notifications via that queue: struct watch_notification_filter filter = { .nr_filters = 1, .filters = { [0] = { .type = WATCH_TYPE_KEY_NOTIFY, .subtype_filter[0] = UINT_MAX, }, }, }; ioctl(fds[1], IOC_WATCH_QUEUE_SET_FILTER, &filter); keyctl_watch_key(KEY_SPEC_SESSION_KEYRING, fds[1], 0x01); After that, records will be placed into the queue when events occur in which keys are changed in some way. Records are of the following format: struct key_notification { struct watch_notification watch; __u32 key_id; __u32 aux; } *n; Where: n->watch.type will be WATCH_TYPE_KEY_NOTIFY. n->watch.subtype will indicate the type of event, such as NOTIFY_KEY_REVOKED. n->watch.info & WATCH_INFO_LENGTH will indicate the length of the record. n->watch.info & WATCH_INFO_ID will be the second argument to keyctl_watch_key(), shifted. n->key will be the ID of the affected key. n->aux will hold subtype-dependent information, such as the key being linked into the keyring specified by n->key in the case of NOTIFY_KEY_LINKED. Note that it is permissible for event records to be of variable length - or, at least, the length may be dependent on the subtype. Note also that the queue can be shared between multiple notifications of various types. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: James Morris <jamorris@linux.microsoft.com>
2020-05-19security: Add hooks to rule on setting a watchDavid Howells
Add security hooks that will allow an LSM to rule on whether or not a watch may be set. More than one hook is required as the watches watch different types of object. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jamorris@linux.microsoft.com> cc: Casey Schaufler <casey@schaufler-ca.com> cc: Stephen Smalley <sds@tycho.nsa.gov> cc: linux-security-module@vger.kernel.org
2020-05-19security: Add a hook for the point of notification insertionDavid Howells
Add a security hook that allows an LSM to rule on whether a notification message is allowed to be inserted into a particular watch queue. The hook is given the following information: (1) The credentials of the triggerer (which may be init_cred for a system notification, eg. a hardware error). (2) The credentials of the whoever set the watch. (3) The notification message. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jamorris@linux.microsoft.com> cc: Casey Schaufler <casey@schaufler-ca.com> cc: Stephen Smalley <sds@tycho.nsa.gov> cc: linux-security-module@vger.kernel.org
2020-05-19proc: proc_pid_ns takes super_block as an argumentAlexey Gladkov
syzbot found that touch /proc/testfile causes NULL pointer dereference at tomoyo_get_local_path() because inode of the dentry is NULL. Before c59f415a7cb6, Tomoyo received pid_ns from proc's s_fs_info directly. Since proc_pid_ns() can only work with inode, using it in the tomoyo_get_local_path() was wrong. To avoid creating more functions for getting proc_ns, change the argument type of the proc_pid_ns() function. Then, Tomoyo can use the existing super_block to get pid_ns. Link: https://lkml.kernel.org/r/0000000000002f0c7505a5b0e04c@google.com Link: https://lkml.kernel.org/r/20200518180738.2939611-1-gladkov.alexey@gmail.com Reported-by: syzbot+c1af344512918c61362c@syzkaller.appspotmail.com Fixes: c59f415a7cb6 ("Use proc_pid_ns() to get pid_namespace from the proc superblock") Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-05-18Merge branch 'fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity Pull integrity fixes from Mimi Zohar: "A couple of miscellaneous bug fixes for the integrity subsystem: IMA: - Properly modify the open flags in order to calculate the file hash. - On systems requiring the IMA policy to be signed, the policy is loaded differently. Don't differentiate between "enforce" and either "log" or "fix" modes how the policy is loaded. EVM: - Two patches to fix an EVM race condition, normally the result of attempting to load an unsupported hash algorithm. - Use the lockless RCU version for walking an append only list" * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: evm: Fix a small race in init_desc() evm: Fix RCU list related warnings ima: Fix return value of ima_write_policy() evm: Check also if *tfm is an error pointer in init_desc() ima: Set file->f_mode instead of file->f_flags in ima_calc_file_hash()
2020-05-15apparmor: Use true and false for bool variableZou Wei
Fixes coccicheck warnings: security/apparmor/file.c:162:9-10: WARNING: return of 0/1 in function 'is_deleted' with return type bool security/apparmor/file.c:362:9-10: WARNING: return of 0/1 in function 'xindex_is_subset' with return type bool security/apparmor/policy_unpack.c:246:9-10: WARNING: return of 0/1 in function 'unpack_X' with return type bool security/apparmor/policy_unpack.c:292:9-10: WARNING: return of 0/1 in function 'unpack_nameX' with return type bool security/apparmor/policy_unpack.c:646:8-9: WARNING: return of 0/1 in function 'unpack_rlimits' with return type bool security/apparmor/policy_unpack.c:604:8-9: WARNING: return of 0/1 in function 'unpack_secmark' with return type bool security/apparmor/policy_unpack.c:538:8-9: WARNING: return of 0/1 in function 'unpack_trans_table' with return type bool security/apparmor/policy_unpack.c:327:9-10: WARNING: return of 0/1 in function 'unpack_u32' with return type bool security/apparmor/policy_unpack.c:345:9-10: WARNING: return of 0/1 in function 'unpack_u64' with return type bool security/apparmor/policy_unpack.c:309:9-10: WARNING: return of 0/1 in function 'unpack_u8' with return type bool security/apparmor/policy_unpack.c:568:8-9: WARNING: return of 0/1 in function 'unpack_xattrs' with return type bool security/apparmor/policy_unpack.c:1007:10-11: WARNING: return of 0/1 in function 'verify_dfa_xindex' with return type bool security/apparmor/policy_unpack.c:997:9-10: WARNING: return of 0/1 in function 'verify_xindex' with return type bool Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zou Wei <zou_wei@huawei.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-05-15security/apparmor/label.c: Clean code by removing redundant instructionsMateusz Nosek
Previously 'label->proxy->label' value checking and conditional reassigning were done twice in the same function. The second one is redundant and can be removed. Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-05-15apparmor: Replace zero-length array with flexible-arrayGustavo A. R. Silva
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-05-15bpf, capability: Introduce CAP_BPFAlexei Starovoitov
Split BPF operations that are allowed under CAP_SYS_ADMIN into combination of CAP_BPF, CAP_PERFMON, CAP_NET_ADMIN. For backward compatibility include them in CAP_SYS_ADMIN as well. The end result provides simple safety model for applications that use BPF: - to load tracing program types BPF_PROG_TYPE_{KPROBE, TRACEPOINT, PERF_EVENT, RAW_TRACEPOINT, etc} use CAP_BPF and CAP_PERFMON - to load networking program types BPF_PROG_TYPE_{SCHED_CLS, XDP, SK_SKB, etc} use CAP_BPF and CAP_NET_ADMIN There are few exceptions from this rule: - bpf_trace_printk() is allowed in networking programs, but it's using tracing mechanism, hence this helper needs additional CAP_PERFMON if networking program is using this helper. - BPF_F_ZERO_SEED flag for hash/lru map is allowed under CAP_SYS_ADMIN only to discourage production use. - BPF HW offload is allowed under CAP_SYS_ADMIN. - bpf_probe_write_user() is allowed under CAP_SYS_ADMIN only. CAPs are not checked at attach/detach time with two exceptions: - loading BPF_PROG_TYPE_CGROUP_SKB is allowed for unprivileged users, hence CAP_NET_ADMIN is required at attach time. - flow_dissector detach doesn't check prog FD at detach, hence CAP_NET_ADMIN is required at detach time. CAP_SYS_ADMIN is required to iterate BPF objects (progs, maps, links) via get_next_id command and convert them to file descriptor via GET_FD_BY_ID command. This restriction guarantees that mutliple tasks with CAP_BPF are not able to affect each other. That leads to clean isolation of tasks. For example: task A with CAP_BPF and CAP_NET_ADMIN loads and attaches a firewall via bpf_link. task B with the same capabilities cannot detach that firewall unless task A explicitly passed link FD to task B via scm_rights or bpffs. CAP_SYS_ADMIN can still detach/unload everything. Two networking user apps with CAP_SYS_ADMIN and CAP_NET_ADMIN can accidentely mess with each other programs and maps. Two networking user apps with CAP_NET_ADMIN and CAP_BPF cannot affect each other. CAP_NET_ADMIN + CAP_BPF allows networking programs access only packet data. Such networking progs cannot access arbitrary kernel memory or leak pointers. bpftool, bpftrace, bcc tools binaries should NOT be installed with CAP_BPF and CAP_PERFMON, since unpriv users will be able to read kernel secrets. But users with these two permissions will be able to use these tracing tools. CAP_PERFMON is least secure, since it allows kprobes and kernel memory access. CAP_NET_ADMIN can stop network traffic via iproute2. CAP_BPF is the safest from security point of view and harmless on its own. Having CAP_BPF and/or CAP_NET_ADMIN is not enough to write into arbitrary map and if that map is used by firewall-like bpf prog. CAP_BPF allows many bpf prog_load commands in parallel. The verifier may consume large amount of memory and significantly slow down the system. Existing unprivileged BPF operations are not affected. In particular unprivileged users are allowed to load socket_filter and cg_skb program types and to create array, hash, prog_array, map-in-map map types. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200513230355.7858-2-alexei.starovoitov@gmail.com
2020-05-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-05-14 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Merged tag 'perf-for-bpf-2020-05-06' from tip tree that includes CAP_PERFMON. 2) support for narrow loads in bpf_sock_addr progs and additional helpers in cg-skb progs, from Andrey. 3) bpf benchmark runner, from Andrii. 4) arm and riscv JIT optimizations, from Luke. 5) bpf iterator infrastructure, from Yonghong. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-14evm: Fix a small race in init_desc()Dan Carpenter
The IS_ERR_OR_NULL() function has two conditions and if we got really unlucky we could hit a race where "ptr" started as an error pointer and then was set to NULL. Both conditions would be false even though the pointer at the end was NULL. This patch fixes the problem by ensuring that "*tfm" can only be NULL or valid. I have introduced a "tmp_tfm" variable to make that work. I also reversed a condition and pulled the code in one tab. Reported-by: Roberto Sassu <roberto.sassu@huawei.com> Fixes: 53de3b080d5e ("evm: Check also if *tfm is an error pointer in init_desc()") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Roberto Sassu <roberto.sassu@huawei.com> Acked-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-05-14lockdown: Allow unprivileged users to see lockdown statusJeremy Cline
A number of userspace tools, such as systemtap, need a way to see the current lockdown state so they can gracefully deal with the kernel being locked down. The state is already exposed in /sys/kernel/security/lockdown, but is only readable by root. Adjust the permissions so unprivileged users can read the state. Fixes: 000d388ed3bb ("security: Add a static lockdown policy LSM") Cc: Frank Ch. Eigler <fche@redhat.com> Signed-off-by: Jeremy Cline <jcline@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2020-05-12selinux: netlabel: Remove unused inline functionYueHaibing
There's no callers in-tree. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-05-12tomoyo: use true for bool variableZou Wei
Fixes coccicheck warning: security/tomoyo/common.c:1028:2-13: WARNING: Assignment of 0/1 to bool variable Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zou Wei <zou_wei@huawei.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
2020-05-11Smack: Remove unused inline function smk_ad_setfield_u_fs_path_mntYueHaibing
commit a269434d2fb4 ("LSM: separate LSM_AUDIT_DATA_DENTRY from LSM_AUDIT_DATA_PATH") left behind this, remove it. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2020-05-08KEYS: encrypted: use crypto_shash_tfm_digest()Eric Biggers
Instead of manually allocating a 'struct shash_desc' on the stack and calling crypto_shash_digest(), switch to using the new helper function crypto_shash_tfm_digest() which does this for us. Cc: keyrings@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-05-07evm: Fix possible memory leak in evm_calc_hmac_or_hash()Roberto Sassu
Don't immediately return if the signature is portable and security.ima is not present. Just set error so that memory allocated is freed before returning from evm_calc_hmac_or_hash(). Fixes: 50b977481fce9 ("EVM: Add support for portable signature format") Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Cc: stable@vger.kernel.org Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-05-07ima: Set again build_ima_appraise variableKrzysztof Struczynski
After adding the new add_rule() function in commit c52657d93b05 ("ima: refactor ima_init_policy()"), all appraisal flags are added to the temp_ima_appraise variable. Revert to the previous behavior instead of removing build_ima_appraise, to benefit from the protection offered by __ro_after_init. The mentioned commit introduced a bug, as it makes all the flags modifiable, while build_ima_appraise flags can be protected with __ro_after_init. Cc: stable@vger.kernel.org # 5.0.x Fixes: c52657d93b05 ("ima: refactor ima_init_policy()") Co-developed-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-05-07ima: Remove redundant policy rule set in add_rules()Krzysztof Struczynski
Function ima_appraise_flag() returns the flag to be set in temp_ima_appraise depending on the hook identifier passed as an argument. It is not necessary to set the flag again for the POLICY_CHECK hook. Signed-off-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-05-07ima: Fix ima digest hash table key calculationKrzysztof Struczynski
Function hash_long() accepts unsigned long, while currently only one byte is passed from ima_hash_key(), which calculates a key for ima_htable. Given that hashing the digest does not give clear benefits compared to using the digest itself, remove hash_long() and return the modulus calculated on the first two bytes of the digest with the number of slots. Also reduce the depth of the hash table by doubling the number of slots. Cc: stable@vger.kernel.org Fixes: 3323eec921ef ("integrity: IMA as an integrity service provider") Co-developed-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com> Acked-by: David.Laight@aculab.com (big endian system concerns) Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-05-07evm: Fix RCU list related warningsMadhuparna Bhowmik
This patch fixes the following warning and few other instances of traversal of evm_config_xattrnames list: [ 32.848432] ============================= [ 32.848707] WARNING: suspicious RCU usage [ 32.848966] 5.7.0-rc1-00006-ga8d5875ce5f0b #1 Not tainted [ 32.849308] ----------------------------- [ 32.849567] security/integrity/evm/evm_main.c:231 RCU-list traversed in non-reader section!! Since entries are only added to the list and never deleted, use list_for_each_entry_lockless() instead of list_for_each_entry_rcu for traversing the list. Also, add a relevant comment in evm_secfs.c to indicate this fact. Reported-by: kernel test robot <lkp@intel.com> Suggested-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> (RCU viewpoint) Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-05-07ima: Fix return value of ima_write_policy()Roberto Sassu
This patch fixes the return value of ima_write_policy() when a new policy is directly passed to IMA and the current policy requires appraisal of the file containing the policy. Currently, if appraisal is not in ENFORCE mode, ima_write_policy() returns 0 and leads user space applications to an endless loop. Fix this issue by denying the operation regardless of the appraisal mode. Cc: stable@vger.kernel.org # 4.10.x Fixes: 19f8a84713edc ("ima: measure and appraise the IMA policy itself") Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-05-07evm: Check also if *tfm is an error pointer in init_desc()Roberto Sassu
This patch avoids a kernel panic due to accessing an error pointer set by crypto_alloc_shash(). It occurs especially when there are many files that require an unsupported algorithm, as it would increase the likelihood of the following race condition: Task A: *tfm = crypto_alloc_shash() <= error pointer Task B: if (*tfm == NULL) <= *tfm is not NULL, use it Task B: rc = crypto_shash_init(desc) <= panic Task A: *tfm = NULL This patch uses the IS_ERR_OR_NULL macro to determine whether or not a new crypto context must be created. Cc: stable@vger.kernel.org Fixes: d46eb3699502b ("evm: crypto hash replaced by shash") Co-developed-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com> Signed-off-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-05-07ima: Set file->f_mode instead of file->f_flags in ima_calc_file_hash()Roberto Sassu
Commit a408e4a86b36 ("ima: open a new file instance if no read permissions") tries to create a new file descriptor to calculate a file digest if the file has not been opened with O_RDONLY flag. However, if a new file descriptor cannot be obtained, it sets the FMODE_READ flag to file->f_flags instead of file->f_mode. This patch fixes this issue by replacing f_flags with f_mode as it was before that commit. Cc: stable@vger.kernel.org # 4.20.x Fixes: a408e4a86b36 ("ima: open a new file instance if no read permissions") Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-05-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Conflicts were all overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-06Merge tag 'perf-for-bpf-2020-05-06' of ↵Alexei Starovoitov
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into bpf-next CAP_PERFMON for BPF
2020-05-06Smack:- Remove redundant inode_smack cacheCasey Schaufler
The inode_smack cache is no longer used. Remove it. Signed-off-by: Vishal Goel <vishal.goel@samsung.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2020-05-06Smack:- Remove mutex lock "smk_lock" from inode_smackCasey Schaufler
"smk_lock" mutex is used during inode instantiation in smack_d_instantiate()function. It has been used to avoid simultaneous access on same inode security structure. Since smack related initialization is done only once i.e during inode creation. If the inode has already been instantiated then smack_d_instantiate() function just returns without doing anything. So it means mutex lock is required only during inode creation. But since 2 processes can't create same inodes or files simultaneously. Also linking or some other file operation can't be done simultaneously when the file is getting created since file lookup will fail before dentry inode linkup which is done after smack initialization. So no mutex lock is required in inode_smack structure. It will save memory as well as improve some performance. If 40000 inodes are created in system, it will save 1.5 MB on 32-bit systems & 2.8 MB on 64-bit systems. Signed-off-by: Vishal Goel <vishal.goel@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2020-05-06Smack: slab-out-of-bounds in vsscanfCasey Schaufler
Add barrier to soob. Return -EOVERFLOW if the buffer is exceeded. Suggested-by: Hillf Danton <hdanton@sina.com> Reported-by: syzbot+bfdd4a2f07be52351350@syzkaller.appspotmail.com Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2020-05-06smack: remove redundant structure variable from header.Maninder Singh
commit afb1cbe37440 ("LSM: Infrastructure management of the inode security") removed usage of smk_rcu, thus removing it from structure. Signed-off-by: Maninder Singh <maninder1.s@samsung.com> Signed-off-by: Vaneet Narang <v.narang@samsung.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2020-05-06smack: avoid unused 'sip' variable warningArnd Bergmann
The mix of IS_ENABLED() and #ifdef checks has left a combination that causes a warning about an unused variable: security/smack/smack_lsm.c: In function 'smack_socket_connect': security/smack/smack_lsm.c:2838:24: error: unused variable 'sip' [-Werror=unused-variable] 2838 | struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap; Change the code to use C-style checks consistently so the compiler can handle it correctly. Fixes: 87fbfffcc89b ("broken ping to ipv6 linklocal addresses on debian buster") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2020-05-01selinux: do not allocate hashtabs dynamicallyOndrej Mosnacek
It is simpler to allocate them statically in the corresponding structure, avoiding unnecessary kmalloc() calls and pointer dereferencing. Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> [PM: manual merging required in policydb.c] Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-05-01selinux: fix return value on error in policydb_read()Ondrej Mosnacek
The value of rc is still zero from the last assignment when the error path is taken. Fix it by setting it to -ENOMEM before the hashtab_create() call. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: e67b2ec9f617 ("selinux: store role transitions in a hash table") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-05-01selinux: simplify range_write()Ondrej Mosnacek
No need to traverse the hashtab to count its elements, hashtab already tracks it for us. Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>