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2017-10-20bpf: remove mark access for SK_SKB program typesJohn Fastabend
The skb->mark field is a union with reserved_tailroom which is used in the TCP code paths from stream memory allocation. Allowing SK_SKB programs to set this field creates a conflict with future code optimizations, such as "gifting" the skb to the egress path instead of creating a new skb and doing a memcpy. Because we do not have a released version of SK_SKB yet lets just remove it for now. A more appropriate scratch pad to use at the socket layer is dev_scratch, but lets add that in future kernels when needed. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-20bpf: avoid preempt enable/disable in sockmap using tcp_skb_cb regionJohn Fastabend
SK_SKB BPF programs are run from the socket/tcp context but early in the stack before much of the TCP metadata is needed in tcp_skb_cb. So we can use some unused fields to place BPF metadata needed for SK_SKB programs when implementing the redirect function. This allows us to drop the preempt disable logic. It does however require an API change so sk_redirect_map() has been updated to additionally provide ctx_ptr to skb. Note, we do however continue to disable/enable preemption around actual BPF program running to account for map updates. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16dev_ioctl: add missing NETDEV_CHANGE_TX_QUEUE_LEN event notificationXin Long
When changing dev tx_queue_len via netlink or net-sysfs, a NETDEV_CHANGE_TX_QUEUE_LEN event notification will be called. But dev_ioctl missed this event notification, which could cause no userspace notification would be sent. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16tun: call dev_get_valid_name() before register_netdevice()Cong Wang
register_netdevice() could fail early when we have an invalid dev name, in which case ->ndo_uninit() is not called. For tun device, this is a problem because a timer etc. are already initialized and it expects ->ndo_uninit() to clean them up. We could move these initializations into a ->ndo_init() so that register_netdevice() knows better, however this is still complicated due to the logic in tun_detach(). Therefore, I choose to just call dev_get_valid_name() before register_netdevice(), which is quicker and much easier to audit. And for this specific case, it is already enough. Fixes: 96442e42429e ("tuntap: choose the txq based on rxq") Reported-by: Dmitry Alexeev <avekceeb@gmail.com> Cc: Jason Wang <jasowang@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16net: enable interface alias removal via rtnlNicolas Dichtel
IFLA_IFALIAS is defined as NLA_STRING. It means that the minimal length of the attribute is 1 ("\0"). However, to remove an alias, the attribute length must be 0 (see dev_set_alias()). Let's define the type to NLA_BINARY to allow 0-length string, so that the alias can be removed. Example: $ ip l s dummy0 alias foo $ ip l l dev dummy0 5: dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/ether ae:20:30:4f:a7:f3 brd ff:ff:ff:ff:ff:ff alias foo Before the patch: $ ip l s dummy0 alias "" RTNETLINK answers: Numerical result out of range After the patch: $ ip l s dummy0 alias "" $ ip l l dev dummy0 5: dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/ether ae:20:30:4f:a7:f3 brd ff:ff:ff:ff:ff:ff CC: Oliver Hartkopp <oliver@hartkopp.net> CC: Stephen Hemminger <stephen@networkplumber.org> Fixes: 96ca4a2cc145 ("net: remove ifalias on empty given alias") Reported-by: Julien FLoret <julien.floret@6wind.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16rtnetlink: do not set notification for tx_queue_len in do_setlinkXin Long
NETDEV_CHANGE_TX_QUEUE_LEN event process in rtnetlink_event would send a notification for userspace and tx_queue_len's setting in do_setlink would trigger NETDEV_CHANGE_TX_QUEUE_LEN. So it shouldn't set DO_SETLINK_NOTIFY status for this change to send a notification any more. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16rtnetlink: check DO_SETLINK_NOTIFY correctly in do_setlinkXin Long
The check 'status & DO_SETLINK_NOTIFY' in do_setlink doesn't really work after status & DO_SETLINK_MODIFIED, as: DO_SETLINK_MODIFIED 0x1 DO_SETLINK_NOTIFY 0x3 Considering that notifications are suppposed to be sent only when status have the flag DO_SETLINK_NOTIFY, the right check would be: (status & DO_SETLINK_NOTIFY) == DO_SETLINK_NOTIFY This would avoid lots of duplicated notifications when setting some properties of a link. Fixes: ba9989069f4e ("rtnl/do_setlink(): notify when a netdev is modified") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: David Ahern <dsahern@gmail.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16rtnetlink: bring NETDEV_CHANGEUPPER event process back in rtnetlink_eventXin Long
libteam needs this event notification in userspace when dev's master dev has been changed. After this, the redundant notifications issue would be fixed in the later patch 'rtnetlink: check DO_SETLINK_NOTIFY correctly in do_setlink'. Fixes: b6b36eb23a46 ("rtnetlink: Do not generate notifications for NETDEV_CHANGEUPPER event") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16rtnetlink: bring NETDEV_POST_TYPE_CHANGE event process back in rtnetlink_eventXin Long
As I said in patch 'rtnetlink: bring NETDEV_CHANGEMTU event process back in rtnetlink_event', removing NETDEV_POST_TYPE_CHANGE event was not the right fix for the redundant notifications issue. So bring this event process back to rtnetlink_event and the old redundant notifications issue would be fixed in the later patch 'rtnetlink: check DO_SETLINK_NOTIFY correctly in do_setlink'. Fixes: aef091ae58aa ("rtnetlink: Do not generate notifications for POST_TYPE_CHANGE event") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16rtnetlink: bring NETDEV_CHANGE_TX_QUEUE_LEN event process back in ↵Xin Long
rtnetlink_event The same fix for changing mtu in the patch 'rtnetlink: bring NETDEV_CHANGEMTU event process back in rtnetlink_event' is needed for changing tx_queue_len. Note that the redundant notifications issue for tx_queue_len will be fixed in the later patch 'rtnetlink: do not send notification for tx_queue_len in do_setlink'. Fixes: 27b3b551d8a7 ("rtnetlink: Do not generate notifications for NETDEV_CHANGE_TX_QUEUE_LEN event") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16rtnetlink: bring NETDEV_CHANGEMTU event process back in rtnetlink_eventXin Long
Commit 085e1a65f04f ("rtnetlink: Do not generate notifications for MTU events") tried to fix the redundant notifications issue when ip link set mtu by removing NETDEV_CHANGEMTU event process in rtnetlink_event. But it also resulted in no notification generated when dev's mtu is changed via other methods, like: 'ifconfig eth1 mtu 1400' or 'echo 1400 > /sys/class/net/eth1/mtu' It would cause users not to be notified by this change. This patch is to fix it by bringing NETDEV_CHANGEMTU event back into rtnetlink_event, and the redundant notifications issue will be fixed in the later patch 'rtnetlink: check DO_SETLINK_NOTIFY correctly in do_setlink'. Fixes: 085e1a65f04f ("rtnetlink: Do not generate notifications for MTU events") Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-14net: fix typo in skbuff.cWenhua Shi
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-10net: call cgroup_sk_alloc() earlier in sk_clone_lock()Eric Dumazet
If for some reason, the newly allocated child need to be freed, we will call cgroup_put() (via sk_free_unlock_clone()) while the corresponding cgroup_get() was not yet done, and we will free memory too soon. Fixes: d979a39d7242 ("cgroup: duplicate cgroup reference when cloning sockets") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-10Revert "net: defer call to cgroup_sk_alloc()"Eric Dumazet
This reverts commit fbb1fb4ad415cb31ce944f65a5ca700aaf73a227. This was not the proper fix, lets cleanly revert it, so that following patch can be carried to stable versions. sock_cgroup_ptr() callers do not expect a NULL return value. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-09net: defer call to cgroup_sk_alloc()Eric Dumazet
sk_clone_lock() might run while TCP/DCCP listener already vanished. In order to prevent use after free, it is better to defer cgroup_sk_alloc() to the point we know both parent and child exist, and from process context. Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-09net: memcontrol: defer call to mem_cgroup_sk_alloc()Eric Dumazet
Instead of calling mem_cgroup_sk_alloc() from BH context, it is better to call it from inet_csk_accept() in process context. Not only this removes code in mem_cgroup_sk_alloc(), but it also fixes a bug since listener might have been dismantled and css_get() might cause a use-after-free. Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-03net: rtnetlink: fix info leak in RTM_GETSTATS callNikolay Aleksandrov
When RTM_GETSTATS was added the fields of its header struct were not all initialized when returning the result thus leaking 4 bytes of information to user-space per rtnl_fill_statsinfo call, so initialize them now. Thanks to Alexander Potapenko for the detailed report and bisection. Reported-by: Alexander Potapenko <glider@google.com> Fixes: 10c9ead9f3c6 ("rtnetlink: add new RTM_GETSTATS message to dump link stats") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-02socket, bpf: fix possible use after freeEric Dumazet
Starting from linux-4.4, 3WHS no longer takes the listener lock. Since this time, we might hit a use-after-free in sk_filter_charge(), if the filter we got in the memcpy() of the listener content just happened to be replaced by a thread changing listener BPF filter. To fix this, we need to make sure the filter refcount is not already zero before incrementing it again. Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets") Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-28net: Set sk_prot_creator when cloning sockets to the right protoChristoph Paasch
sk->sk_prot and sk->sk_prot_creator can differ when the app uses IPV6_ADDRFORM (transforming an IPv6-socket to an IPv4-one). Which is why sk_prot_creator is there to make sure that sk_prot_free() does the kmem_cache_free() on the right kmem_cache slab. Now, if such a socket gets transformed back to a listening socket (using connect() with AF_UNSPEC) we will allocate an IPv4 tcp_sock through sk_clone_lock() when a new connection comes in. But sk_prot_creator will still point to the IPv6 kmem_cache (as everything got copied in sk_clone_lock()). When freeing, we will thus put this memory back into the IPv6 kmem_cache although it was allocated in the IPv4 cache. I have seen memory corruption happening because of this. With slub-debugging and MEMCG_KMEM enabled this gives the warning "cache_from_obj: Wrong slab cache. TCPv6 but object is from TCP" A C-program to trigger this: void main(void) { int fd = socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP); int new_fd, newest_fd, client_fd; struct sockaddr_in6 bind_addr; struct sockaddr_in bind_addr4, client_addr1, client_addr2; struct sockaddr unsp; int val; memset(&bind_addr, 0, sizeof(bind_addr)); bind_addr.sin6_family = AF_INET6; bind_addr.sin6_port = ntohs(42424); memset(&client_addr1, 0, sizeof(client_addr1)); client_addr1.sin_family = AF_INET; client_addr1.sin_port = ntohs(42424); client_addr1.sin_addr.s_addr = inet_addr("127.0.0.1"); memset(&client_addr2, 0, sizeof(client_addr2)); client_addr2.sin_family = AF_INET; client_addr2.sin_port = ntohs(42421); client_addr2.sin_addr.s_addr = inet_addr("127.0.0.1"); memset(&unsp, 0, sizeof(unsp)); unsp.sa_family = AF_UNSPEC; bind(fd, (struct sockaddr *)&bind_addr, sizeof(bind_addr)); listen(fd, 5); client_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); connect(client_fd, (struct sockaddr *)&client_addr1, sizeof(client_addr1)); new_fd = accept(fd, NULL, NULL); close(fd); val = AF_INET; setsockopt(new_fd, SOL_IPV6, IPV6_ADDRFORM, &val, sizeof(val)); connect(new_fd, &unsp, sizeof(unsp)); memset(&bind_addr4, 0, sizeof(bind_addr4)); bind_addr4.sin_family = AF_INET; bind_addr4.sin_port = ntohs(42421); bind(new_fd, (struct sockaddr *)&bind_addr4, sizeof(bind_addr4)); listen(new_fd, 5); client_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); connect(client_fd, (struct sockaddr *)&client_addr2, sizeof(client_addr2)); newest_fd = accept(new_fd, NULL, NULL); close(new_fd); close(client_fd); close(new_fd); } As far as I can see, this bug has been there since the beginning of the git-days. Signed-off-by: Christoph Paasch <cpaasch@apple.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-22net: orphan frags on stand-alone ptype in dev_queue_xmit_nitWillem de Bruijn
Zerocopy skbs frags are copied when the skb is looped to a local sock. Commit 1080e512d44d ("net: orphan frags on receive") introduced calls to skb_orphan_frags to deliver_skb and __netif_receive_skb for this. With msg_zerocopy, these skbs can also exist in the tx path and thus loop from dev_queue_xmit_nit. This already calls deliver_skb in its loop. But it does not orphan before a separate pt_prev->func(). Add the missing skb_orphan_frags_rx. Changes v1->v2: handle skb_orphan_frags_rx failure Fixes: 1f8b977ab32d ("sock: enable MSG_ZEROCOPY") Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-21net: ethtool: Add back transceiver typeFlorian Fainelli
Commit 3f1ac7a700d0 ("net: ethtool: add new ETHTOOL_xLINKSETTINGS API") deprecated the ethtool_cmd::transceiver field, which was fine in premise, except that the PHY library was actually using it to report the type of transceiver: internal or external. Use the first word of the reserved field to put this __u8 transceiver field back in. It is made read-only, and we don't expect the ETHTOOL_xLINKSETTINGS API to be doing anything with this anyway, so this is mostly for the legacy path where we do: ethtool_get_settings() -> dev->ethtool_ops->get_link_ksettings() -> convert_link_ksettings_to_legacy_settings() to have no information loss compared to the legacy get_settings API. Fixes: 3f1ac7a700d0 ("net: ethtool: add new ETHTOOL_xLINKSETTINGS API") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-20net: change skb->mac_header when Generic XDP calls adjust_headEdward Cree
Since XDP's view of the packet includes the MAC header, moving the start- of-packet with bpf_xdp_adjust_head needs to also update the offset of the MAC header (which is relative to skb->head, not to the skb->data that was changed). Without this, tcpdump sees packets starting from the old MAC header rather than the new one, at least in my tests on the loopback device. Fixes: b5cdae3291f7 ("net: Generic XDP") Signed-off-by: Edward Cree <ecree@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-19bpf: fix ri->map_owner pointer on bpf_prog_reallocDaniel Borkmann
Commit 109980b894e9 ("bpf: don't select potentially stale ri->map from buggy xdp progs") passed the pointer to the prog itself to be loaded into r4 prior on bpf_redirect_map() helper call, so that we can store the owner into ri->map_owner out of the helper. Issue with that is that the actual address of the prog is still subject to change when subsequent rewrites occur that require slow path in bpf_prog_realloc() to alloc more memory, e.g. from patching inlining helper functions or constant blinding. Thus, we really need to take prog->aux as the address we're holding, which also works with prog clones as they share the same aux object. Instead of then fetching aux->prog during runtime, which could potentially incur cache misses due to false sharing, we are going to just use aux for comparison on the map owner. This will also keep the patchlet of the same size, and later check in xdp_map_invalid() only accesses read-only aux pointer from the prog, it's also in the same cacheline already from prior access when calling bpf_func. Fixes: 109980b894e9 ("bpf: don't select potentially stale ri->map from buggy xdp progs") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-13net_sched: gen_estimator: fix scaling error in bytes/packets samplesEric Dumazet
Denys reported wrong rate estimations with HTB classes. It appears the bug was added in linux-4.10, since my tests where using intervals of one second only. HTB using 4 sec default rate estimators, reported rates were 4x higher. We need to properly scale the bytes/packets samples before integrating them in EWMA. Tested: echo 1 >/sys/module/sch_htb/parameters/htb_rate_est Setup HTB with one class with a rate/cail of 5Gbit Generate traffic on this class tc -s -d cl sh dev eth0 classid 7002:11 class htb 7002:11 parent 7002:1 prio 5 quantum 200000 rate 5Gbit ceil 5Gbit linklayer ethernet burst 80000b/1 mpu 0b cburst 80000b/1 mpu 0b level 0 rate_handle 1 Sent 1488215421648 bytes 982969243 pkt (dropped 0, overlimits 0 requeues 0) rate 5Gbit 412814pps backlog 136260b 2p requeues 0 TCP pkts/rtx 982969327/45 bytes 1488215557414/68130 lended: 22732826 borrowed: 0 giants: 0 tokens: -1684 ctokens: -1684 Fixes: 1c0d32fde5bd ("net_sched: gen_estimator: complete rewrite of rate estimators") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Denys Fedoryshchenko <nuclearcat@nuclearcat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-11xdp: implement xdp_redirect_map for generic XDPJesper Dangaard Brouer
Using bpf_redirect_map is allowed for generic XDP programs, but the appropriate map lookup was never performed in xdp_do_generic_redirect(). Instead the map-index is directly used as the ifindex. For the xdp_redirect_map sample in SKB-mode '-S', this resulted in trying sending on ifindex 0 which isn't valid, resulting in getting SKB packets dropped. Thus, the reported performance numbers are wrong in commit 24251c264798 ("samples/bpf: add option for native and skb mode for redirect apps") for the 'xdp_redirect_map -S' case. Before commit 109980b894e9 ("bpf: don't select potentially stale ri->map from buggy xdp progs") it could crash the kernel. Like this commit also check that the map_owner owner is correct before dereferencing the map pointer. But make sure that this API misusage can be caught by a tracepoint. Thus, allowing userspace via tracepoints to detect misbehaving bpf_progs. Fixes: 6103aa96ec07 ("net: implement XDP_REDIRECT for xdp generic") Fixes: 24251c264798 ("samples/bpf: add option for native and skb mode for redirect apps") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: "The iwlwifi firmware compat fix is in here as well as some other stuff: 1) Fix request socket leak introduced by BPF deadlock fix, from Eric Dumazet. 2) Fix VLAN handling with TXQs in mac80211, from Johannes Berg. 3) Missing __qdisc_drop conversions in prio and qfq schedulers, from Gao Feng. 4) Use after free in netlink nlk groups handling, from Xin Long. 5) Handle MTU update properly in ipv6 gre tunnels, from Xin Long. 6) Fix leak of ipv6 fib tables on netns teardown, from Sabrina Dubroca with follow-on fix from Eric Dumazet. 7) Need RCU and preemption disabled during generic XDP data patch, from John Fastabend" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (54 commits) bpf: make error reporting in bpf_warn_invalid_xdp_action more clear Revert "mdio_bus: Remove unneeded gpiod NULL check" bpf: devmap, use cond_resched instead of cpu_relax bpf: add support for sockmap detach programs net: rcu lock and preempt disable missing around generic xdp bpf: don't select potentially stale ri->map from buggy xdp progs net: tulip: Constify tulip_tbl net: ethernet: ti: netcp_core: no need in netif_napi_del davicom: Display proper debug level up to 6 net: phy: sfp: rename dt properties to match the binding dt-binding: net: sfp binding documentation dt-bindings: add SFF vendor prefix dt-bindings: net: don't confuse with generic PHY property ip6_tunnel: fix setting hop_limit value for ipv6 tunnel ip_tunnel: fix setting ttl and tos value in collect_md mode ipv6: fix typo in fib6_net_exit() tcp: fix a request socket leak sctp: fix missing wake ups in some situations netfilter: xt_hashlimit: fix build error caused by 64bit division netfilter: xt_hashlimit: alloc hashtable with right size ...
2017-09-08bpf: make error reporting in bpf_warn_invalid_xdp_action more clearDaniel Borkmann
Differ between illegal XDP action code and just driver unsupported one to provide better feedback when we throw a one-time warning here. Reason is that with 814abfabef3c ("xdp: add bpf_redirect helper function") not all drivers support the new XDP return code yet and thus they will fall into their 'default' case when checking for return codes after program return, which then triggers a bpf_warn_invalid_xdp_action() stating that the return code is illegal, but from XDP perspective it's not. I decided not to place something like a XDP_ACT_MAX define into uapi i) given we don't have this either for all other program types, ii) future action codes could have further encoding there, which would render such define unsuitable and we wouldn't be able to rip it out again, and iii) we rarely add new action codes. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-08net: rcu lock and preempt disable missing around generic xdpJohn Fastabend
do_xdp_generic must be called inside rcu critical section with preempt disabled to ensure BPF programs are valid and per-cpu variables used for redirect operations are consistent. This patch ensures this is true and fixes the splat below. The netif_receive_skb_internal() code path is now broken into two rcu critical sections. I decided it was better to limit the preempt_enable/disable block to just the xdp static key portion and the fallout is more rcu_read_lock/unlock calls. Seems like the best option to me. [ 607.596901] ============================= [ 607.596906] WARNING: suspicious RCU usage [ 607.596912] 4.13.0-rc4+ #570 Not tainted [ 607.596917] ----------------------------- [ 607.596923] net/core/dev.c:3948 suspicious rcu_dereference_check() usage! [ 607.596927] [ 607.596927] other info that might help us debug this: [ 607.596927] [ 607.596933] [ 607.596933] rcu_scheduler_active = 2, debug_locks = 1 [ 607.596938] 2 locks held by pool/14624: [ 607.596943] #0: (rcu_read_lock_bh){......}, at: [<ffffffff95445ffd>] ip_finish_output2+0x14d/0x890 [ 607.596973] #1: (rcu_read_lock_bh){......}, at: [<ffffffff953c8e3a>] __dev_queue_xmit+0x14a/0xfd0 [ 607.597000] [ 607.597000] stack backtrace: [ 607.597006] CPU: 5 PID: 14624 Comm: pool Not tainted 4.13.0-rc4+ #570 [ 607.597011] Hardware name: Dell Inc. Precision Tower 5810/0HHV7N, BIOS A17 03/01/2017 [ 607.597016] Call Trace: [ 607.597027] dump_stack+0x67/0x92 [ 607.597040] lockdep_rcu_suspicious+0xdd/0x110 [ 607.597054] do_xdp_generic+0x313/0xa50 [ 607.597068] ? time_hardirqs_on+0x5b/0x150 [ 607.597076] ? mark_held_locks+0x6b/0xc0 [ 607.597088] ? netdev_pick_tx+0x150/0x150 [ 607.597117] netif_rx_internal+0x205/0x3f0 [ 607.597127] ? do_xdp_generic+0xa50/0xa50 [ 607.597144] ? lock_downgrade+0x2b0/0x2b0 [ 607.597158] ? __lock_is_held+0x93/0x100 [ 607.597187] netif_rx+0x119/0x190 [ 607.597202] loopback_xmit+0xfd/0x1b0 [ 607.597214] dev_hard_start_xmit+0x127/0x4e0 Fixes: d445516966dc ("net: xdp: support xdp generic on virtual devices") Fixes: b5cdae3291f7 ("net: Generic XDP") Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-08bpf: don't select potentially stale ri->map from buggy xdp progsDaniel Borkmann
We can potentially run into a couple of issues with the XDP bpf_redirect_map() helper. The ri->map in the per CPU storage can become stale in several ways, mostly due to misuse, where we can then trigger a use after free on the map: i) prog A is calling bpf_redirect_map(), returning XDP_REDIRECT and running on a driver not supporting XDP_REDIRECT yet. The ri->map on that CPU becomes stale when the XDP program is unloaded on the driver, and a prog B loaded on a different driver which supports XDP_REDIRECT return code. prog B would have to omit calling to bpf_redirect_map() and just return XDP_REDIRECT, which would then access the freed map in xdp_do_redirect() since not cleared for that CPU. ii) prog A is calling bpf_redirect_map(), returning a code other than XDP_REDIRECT. prog A is then detached, which triggers release of the map. prog B is attached which, similarly as in i), would just return XDP_REDIRECT without having called bpf_redirect_map() and thus be accessing the freed map in xdp_do_redirect() since not cleared for that CPU. iii) prog A is attached to generic XDP, calling the bpf_redirect_map() helper and returning XDP_REDIRECT. xdp_do_generic_redirect() is currently not handling ri->map (will be fixed by Jesper), so it's not being reset. Later loading a e.g. native prog B which would, say, call bpf_xdp_redirect() and then returns XDP_REDIRECT would find in xdp_do_redirect() that a map was set and uses that causing use after free on map access. Fix thus needs to avoid accessing stale ri->map pointers, naive way would be to call a BPF function from drivers that just resets it to NULL for all XDP return codes but XDP_REDIRECT and including XDP_REDIRECT for drivers not supporting it yet (and let ri->map being handled in xdp_do_generic_redirect()). There is a less intrusive way w/o letting drivers call a reset for each BPF run. The verifier knows we're calling into bpf_xdp_redirect_map() helper, so it can do a small insn rewrite transparent to the prog itself in the sense that it fills R4 with a pointer to the own bpf_prog. We have that pointer at verification time anyway and R4 is allowed to be used as per calling convention we scratch R0 to R5 anyway, so they become inaccessible and program cannot read them prior to a write. Then, the helper would store the prog pointer in the current CPUs struct redirect_info. Later in xdp_do_*_redirect() we check whether the redirect_info's prog pointer is the same as passed xdp_prog pointer, and if that's the case then all good, since the prog holds a ref on the map anyway, so it is always valid at that point in time and must have a reference count of at least 1. If in the unlikely case they are not equal, it means we got a stale pointer, so we clear and bail out right there. Also do reset map and the owning prog in bpf_xdp_redirect(), so that bpf_xdp_redirect_map() and bpf_xdp_redirect() won't get mixed up, only the last call should take precedence. A tc bpf_redirect() doesn't use map anywhere yet, so no need to clear it there since never accessed in that layer. Note that in case the prog is released, and thus the map as well we're still under RCU read critical section at that time and have preemption disabled as well. Once we commit with the __dev_map_insert_ctx() from xdp_do_redirect_map() and set the map to ri->map_to_flush, we still wait for a xdp_do_flush_map() to finish in devmap dismantle time once flush_needed bit is set, so that is fine. Fixes: 97f91a7cf04f ("bpf: add bpf_redirect_map helper routine") Reported-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-07udp: drop head states only when all skb references are gonePaolo Abeni
After commit 0ddf3fb2c43d ("udp: preserve skb->dst if required for IP options processing") we clear the skb head state as soon as the skb carrying them is first processed. Since the same skb can be processed several times when MSG_PEEK is used, we can end up lacking the required head states, and eventually oopsing. Fix this clearing the skb head state only when processing the last skb reference. Reported-by: Eric Dumazet <edumazet@google.com> Fixes: 0ddf3fb2c43d ("udp: preserve skb->dst if required for IP options processing") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-06Merge branch 'for-4.14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "Several notable changes this cycle: - Thread mode was merged. This will be used for cgroup2 support for CPU and possibly other controllers. Unfortunately, CPU controller cgroup2 support didn't make this pull request but most contentions have been resolved and the support is likely to be merged before the next merge window. - cgroup.stat now shows the number of descendant cgroups. - cpuset now can enable the easier-to-configure v2 behavior on v1 hierarchy" * 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits) cpuset: Allow v2 behavior in v1 cgroup cgroup: Add mount flag to enable cpuset to use v2 behavior in v1 cgroup cgroup: remove unneeded checks cgroup: misc changes cgroup: short-circuit cset_cgroup_from_root() on the default hierarchy cgroup: re-use the parent pointer in cgroup_destroy_locked() cgroup: add cgroup.stat interface with basic hierarchy stats cgroup: implement hierarchy limits cgroup: keep track of number of descent cgroups cgroup: add comment to cgroup_enable_threaded() cgroup: remove unnecessary empty check when enabling threaded mode cgroup: update debug controller to print out thread mode information cgroup: implement cgroup v2 thread support cgroup: implement CSS_TASK_ITER_THREADED cgroup: introduce cgroup->dom_cgrp and threaded css_set handling cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS cgroup: reorganize cgroup.procs / task write path cgroup: replace css_set walking populated test with testing cgrp->nr_populated_csets cgroup: distinguish local and children populated states cgroup: remove now unused list_head @pending in cgroup_apply_cftypes() ...
2017-09-05flow_dissector: Add limit for number of headers to dissectTom Herbert
In flow dissector there are no limits to the number of nested encapsulations or headers that might be dissected which makes for a nice DOS attack. This patch sets a limit of the number of headers that flow dissector will parse. Headers includes network layer headers, transport layer headers, shim headers for encapsulation, IPv6 extension headers, etc. The limit for maximum number of headers to parse has be set to fifteen to account for a reasonable number of encapsulations, extension headers, VLAN, in a packet. Note that this limit does not supercede the STOP_AT_* flags which may stop processing before the headers limit is reached. Reported-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Tom Herbert <tom@quantonium.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-05flow_dissector: Cleanup control flowTom Herbert
__skb_flow_dissect is riddled with gotos that make discerning the flow, debugging, and extending the capability difficult. This patch reorganizes things so that we only perform goto's after the two main switch statements (no gotos within the cases now). It also eliminates several goto labels so that there are only two labels that can be target for goto. Reported-by: Alexander Popov <alex.popov@linux.com> Signed-off-by: Tom Herbert <tom@quantonium.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01net: Add module reference to FIB notifiersIdo Schimmel
When a listener registers to the FIB notification chain it receives a dump of the FIB entries and rules from existing address families by invoking their dump operations. While we call into these modules we need to make sure they aren't removed. Do that by increasing their reference count before invoking their dump operations and decrease it afterwards. Fixes: 04b1d4e50e82 ("net: core: Make the FIB notification chain generic") Signed-off-by: Ido Schimmel <idosch@mellanox.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01net: convert (struct ubuf_info)->refcnt to refcount_tEric Dumazet
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. v2: added the change in drivers/vhost/net.c as spotted by Willem. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01net: prepare (struct ubuf_info)->refcnt conversionEric Dumazet
In order to convert this atomic_t refcnt to refcount_t, we need to init the refcount to one to not trigger a 0 -> 1 transition. This also removes one atomic operation in fast path. v2: removed dead code in sock_zerocopy_put_abort() as suggested by Willem. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Three cases of simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01bpf: Collapse offset checks in sock_filter_is_valid_accessDavid Ahern
Make sock_filter_is_valid_access consistent with other is_valid_access helpers. Requested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01mlxsw: spectrum: Forbid linking to devices that have uppersIdo Schimmel
The mlxsw driver relies on NETDEV_CHANGEUPPER events to configure the device in case a port is enslaved to a master netdev such as bridge or bond. Since the driver ignores events unrelated to its ports and their uppers, it's possible to engineer situations in which the device's data path differs from the kernel's. One example to such a situation is when a port is enslaved to a bond that is already enslaved to a bridge. When the bond was enslaved the driver ignored the event - as the bond wasn't one of its uppers - and therefore a bridge port instance isn't created in the device. Until such configurations are supported forbid them by checking that the upper device doesn't have uppers of its own. Fixes: 0d65fc13042f ("mlxsw: spectrum: Implement LAG port join/leave") Signed-off-by: Ido Schimmel <idosch@mellanox.com> Reported-by: Nogah Frankel <nogahf@mellanox.com> Tested-by: Nogah Frankel <nogahf@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01bpf: Allow cgroup sock filters to use get_current_uid_gid helperDavid Ahern
Allow BPF programs run on sock create to use the get_current_uid_gid helper. IPv4 and IPv6 sockets are created in a process context so there is always a valid uid/gid Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01bpf: Add mark and priority to sock options that can be setDavid Ahern
Add socket mark and priority to fields that can be set by ebpf program when a socket is created. Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-31devlink: Add IPv6 header for dpipeArkadi Sharshevsky
This will be used by the IPv6 host table which will be introduced in the following patches. The fields in the header are added per-use. This header is global and can be reused by many drivers. Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-31bridge: add tracepoint in br_fdb_updateRoopa Prabhu
This extends bridge fdb table tracepoints to also cover learned fdb entries in the br_fdb_update path. Note that unlike other tracepoints I have moved this to when the fdb is modified because this is in the datapath and can generate a lot of noise in the trace output. br_fdb_update is also called from added_by_user context in the NTF_USE case which is already traced ..hence the !added_by_user check. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-30devlink: Maintain consistency in mac field nameDavid Ahern
IPv4 name uses "destination ip" as does the IPv6 patch set. Make the mac field consistent. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-29neigh: increase queue_len_bytes to match wmem_defaultEric Dumazet
Florian reported UDP xmit drops that could be root caused to the too small neigh limit. Current limit is 64 KB, meaning that even a single UDP socket would hit it, since its default sk_sndbuf comes from net.core.wmem_default (~212992 bytes on 64bit arches). Once ARP/ND resolution is in progress, we should allow a little more packets to be queued, at least for one producer. Once neigh arp_queue is filled, a rogue socket should hit its sk_sndbuf limit and either block in sendmsg() or return -EAGAIN. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-29bridge: fdb add and delete tracepointsRoopa Prabhu
A few useful tracepoints to trace bridge forwarding database updates. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-29xdp: separate xdp_redirect tracepoint in map caseJesper Dangaard Brouer
Creating as specific xdp_redirect_map variant of the xdp tracepoints allow users to write simpler/faster BPF progs that get attached to these tracepoints. Goal is to still keep the tracepoints in xdp_redirect and xdp_redirect_map similar enough, that a tool can read the top part of the TP_STRUCT and produce similar monitor statistics. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-29xdp: separate xdp_redirect tracepoint in error caseJesper Dangaard Brouer
There is a need to separate the xdp_redirect tracepoint into two tracepoints, for separating the error case from the normal forward case. Due to the extreme speeds XDP is operating at, loading a tracepoint have a measurable impact. Single core XDP REDIRECT (ethtool tuned rx-usecs 25) can do 13.7 Mpps forwarding, but loading a simple bpf_prog at the tracepoint (with a return 0) reduce perf to 10.2 Mpps (CPU E5-1650 v4 @ 3.60GHz, driver: ixgbe) The overhead of loading a bpf-based tracepoint can be calculated to cost 25 nanosec ((1/13782002-1/10267937)*10^9 = -24.83 ns). Using perf record on the tracepoint event, with a non-matching --filter expression, the overhead is much larger. Performance drops to 8.3 Mpps, cost 48 nanosec ((1/13782002-1/8312497)*10^9 = -47.74)) Having a separate tracepoint for err cases, which should be less frequent, allow running a continuous monitor for errors while not affecting the redirect forward performance (this have also been verified by measurements). Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-29xdp: tracepoint xdp_redirect also need a map argumentJesper Dangaard Brouer
To make sense of the map index, the tracepoint user also need to know that map we are talking about. Supply the map pointer but only expose the map->id. The 'to_index' is renamed 'to_ifindex'. In the xdp_redirect_map case, this is the result of the devmap lookup. The map lookup key is exposed as map_index, which is needed to troubleshoot in case the lookup failed. The 'to_ifindex' is placed after 'err' to keep TP_STRUCT as common as possible. This also keeps the TP_STRUCT similar enough, that userspace can write a monitor program, that doesn't need to care about whether bpf_redirect or bpf_redirect_map were used. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-29xdp: remove redundant argument to trace_xdp_redirectJesper Dangaard Brouer
Supplying the action argument XDP_REDIRECT to the tracepoint xdp_redirect is redundant as it is only called in-case this action was specified. Remove the argument, but keep "act" member of the tracepoint struct and populate it with XDP_REDIRECT. This makes it easier to write a common bpf_prog processing events. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>