kernel/linux.git/include/net/sch_generic.h, branch v5.4.146

net: sched: add barrier to ensure correct ordering for lockless qdisc

2021-07-14T14:53:31+00:00

[ Upstream commit 89837eb4b2463c556a123437f242d6c2bc62ce81 ] The spin_trylock() was assumed to contain the implicit barrier needed to ensure the correct ordering between STATE_MISSED setting/clearing and STATE_MISSED checking in commit a90c57f2cedd ("net: sched: fix packet stuck problem for lockless qdisc"). But it turns out that spin_trylock() only has load-acquire semantic, for strongly-ordered system(like x86), the compiler barrier implicitly contained in spin_trylock() seems enough to ensure the correct ordering. But for weakly-orderly system (like arm64), the store-release semantic is needed to ensure the correct ordering as clear_bit() and test_bit() is store operation, see queued_spin_lock(). So add the explicit barrier to ensure the correct ordering for the above case. Fixes: a90c57f2cedd ("net: sched: fix packet stuck problem for lockless qdisc") Signed-off-by: Yunsheng Lin Acked-by: Jakub Kicinski Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: sched: fix packet stuck problem for lockless qdisc

2021-06-03T06:59:13+00:00

[ Upstream commit a90c57f2cedd52a511f739fb55e6244e22e1a2fb ] Lockless qdisc has below concurrent problem: cpu0 cpu1 . . q->enqueue . . . qdisc_run_begin() . . . dequeue_skb() . . . sch_direct_xmit() . . . . q->enqueue . qdisc_run_begin() . return and do nothing . . qdisc_run_end() . cpu1 enqueue a skb without calling __qdisc_run() because cpu0 has not released the lock yet and spin_trylock() return false for cpu1 in qdisc_run_begin(), and cpu0 do not see the skb enqueued by cpu1 when calling dequeue_skb() because cpu1 may enqueue the skb after cpu0 calling dequeue_skb() and before cpu0 calling qdisc_run_end(). Lockless qdisc has below another concurrent problem when tx_action is involved: cpu0(serving tx_action) cpu1 cpu2 . . . . q->enqueue . . qdisc_run_begin() . . dequeue_skb() . . . q->enqueue . . . . sch_direct_xmit() . . . qdisc_run_begin() . . return and do nothing . . . clear __QDISC_STATE_SCHED . . qdisc_run_begin() . . return and do nothing . . . . . . qdisc_run_end() . This patch fixes the above data race by: 1. If the first spin_trylock() return false and STATE_MISSED is not set, set STATE_MISSED and retry another spin_trylock() in case other CPU may not see STATE_MISSED after it releases the lock. 2. reschedule if STATE_MISSED is set after the lock is released at the end of qdisc_run_end(). For tx_action case, STATE_MISSED is also set when cpu1 is at the end if qdisc_run_end(), so tx_action will be rescheduled again to dequeue the skb enqueued by cpu2. Clear STATE_MISSED before retrying a dequeuing when dequeuing returns NULL in order to reduce the overhead of the second spin_trylock() and __netif_schedule() calling. Also clear the STATE_MISSED before calling __netif_schedule() at the end of qdisc_run_end() to avoid doing another round of dequeuing in the pfifo_fast_dequeue(). The performance impact of this patch, tested using pktgen and dummy netdev with pfifo_fast qdisc attached: threads without+this_patch with+this_patch delta 1 2.61Mpps 2.60Mpps -0.3% 2 3.97Mpps 3.82Mpps -3.7% 4 5.62Mpps 5.59Mpps -0.5% 8 2.78Mpps 2.77Mpps -0.3% 16 2.22Mpps 2.22Mpps -0.0% Fixes: 6b3ba9146fe6 ("net: sched: allow qdiscs to handle locking") Acked-by: Jakub Kicinski Tested-by: Juergen Gross Signed-off-by: Yunsheng Lin Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: sched: replaced invalid qdisc tree flush helper in qdisc_replace

2021-02-10T08:25:33+00:00

commit 938e0fcd3253efdef8924714158911286d08cfe1 upstream. Commit e5f0e8f8e456 ("net: sched: introduce and use qdisc tree flush/purge helpers") introduced qdisc tree flush/purge helpers, but erroneously used flush helper instead of purge helper in qdisc_replace function. This issue was found in our CI, that tests various qdisc setups by configuring qdisc and sending data through it. Call of invalid helper sporadically leads to corruption of vt_tree/cf_tree of hfsc_class that causes kernel oops: Oops: 0000 [#1] SMP PTI CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.11.0-8f6859df #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014 RIP: 0010:rb_insert_color+0x18/0x190 Code: c3 31 c0 c3 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 48 8b 07 48 85 c0 0f 84 05 01 00 00 48 8b 10 f6 c2 01 0f 85 34 01 00 00 <48> 8b 4a 08 49 89 d0 48 39 c1 74 7d 48 85 c9 74 32 f6 01 01 75 2d RSP: 0018:ffffc900000b8bb0 EFLAGS: 00010246 RAX: ffff8881ef4c38b0 RBX: ffff8881d956e400 RCX: ffff8881ef4c38b0 RDX: 0000000000000000 RSI: ffff8881d956f0a8 RDI: ffff8881d956e4b0 RBP: 0000000000000000 R08: 000000d5c4e249da R09: 1600000000000000 R10: ffffc900000b8be0 R11: ffffc900000b8b28 R12: 0000000000000001 R13: 000000000000005a R14: ffff8881f0905000 R15: ffff8881f0387d00 FS: 0000000000000000(0000) GS:ffff8881f8b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 00000001f4796004 CR4: 0000000000060ee0 Call Trace: init_vf.isra.19+0xec/0x250 [sch_hfsc] hfsc_enqueue+0x245/0x300 [sch_hfsc] ? fib_rules_lookup+0x12a/0x1d0 ? __dev_queue_xmit+0x4b6/0x930 ? hfsc_delete_class+0x250/0x250 [sch_hfsc] __dev_queue_xmit+0x4b6/0x930 ? ip6_finish_output2+0x24d/0x590 ip6_finish_output2+0x24d/0x590 ? ip6_output+0x6c/0x130 ip6_output+0x6c/0x130 ? __ip6_finish_output+0x110/0x110 mld_sendpack+0x224/0x230 mld_ifc_timer_expire+0x186/0x2c0 ? igmp6_group_dropped+0x200/0x200 call_timer_fn+0x2d/0x150 run_timer_softirq+0x20c/0x480 ? tick_sched_do_timer+0x60/0x60 ? tick_sched_timer+0x37/0x70 __do_softirq+0xf7/0x2cb irq_exit+0xa0/0xb0 smp_apic_timer_interrupt+0x74/0x150 apic_timer_interrupt+0xf/0x20 Fixes: e5f0e8f8e456 ("net: sched: introduce and use qdisc tree flush/purge helpers") Signed-off-by: Alexander Ovechkin Reported-by: Alexander Kuznetsov Acked-by: Dmitry Monakhov Acked-by: Dmitry Yakunin Acked-by: Cong Wang Link: https://lore.kernel.org/r/20210201200049.299153-1-ovov@yandex-team.ru Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net_sched: fix tcm_parent in tc filter dump

2020-05-20T06:20:07+00:00

[ Upstream commit a7df4870d79b00742da6cc93ca2f336a71db77f7 ] When we tell kernel to dump filters from root (ffff:ffff), those filters on ingress (ffff:0000) are matched, but their true parents must be dumped as they are. However, kernel dumps just whatever we tell it, that is either ffff:ffff or ffff:0000: $ nl-cls-list --dev=dummy0 --parent=root cls basic dev dummy0 id none parent root prio 49152 protocol ip match-all cls basic dev dummy0 id :1 parent root prio 49152 protocol ip match-all $ nl-cls-list --dev=dummy0 --parent=ffff: cls basic dev dummy0 id none parent ffff: prio 49152 protocol ip match-all cls basic dev dummy0 id :1 parent ffff: prio 49152 protocol ip match-all This is confusing and misleading, more importantly this is a regression since 4.15, so the old behavior must be restored. And, when tc filters are installed on a tc class, the parent should be the classid, rather than the qdisc handle. Commit edf6711c9840 ("net: sched: remove classid and q fields from tcf_proto") removed the classid we save for filters, we can just restore this classid in tcf_block. Steps to reproduce this: ip li set dev dummy0 up tc qd add dev dummy0 ingress tc filter add dev dummy0 parent ffff: protocol arp basic action pass tc filter show dev dummy0 root Before this patch: filter protocol arp pref 49152 basic filter protocol arp pref 49152 basic handle 0x1 action order 1: gact action pass random type none pass val 0 index 1 ref 1 bind 1 After this patch: filter parent ffff: protocol arp pref 49152 basic filter parent ffff: protocol arp pref 49152 basic handle 0x1 action order 1: gact action pass random type none pass val 0 index 1 ref 1 bind 1 Fixes: a10fa20101ae ("net: sched: propagate q and parent from caller down to tcf_fill_node") Fixes: edf6711c9840 ("net: sched: remove classid and q fields from tcf_proto") Cc: Jamal Hadi Salim Cc: Jiri Pirko Signed-off-by: Cong Wang Acked-by: Jamal Hadi Salim Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: Fix CONFIG_NET_CLS_ACT=n and CONFIG_NFT_FWD_NETDEV={y, m} build

2020-04-01T09:02:18+00:00

commit 2c64605b590edadb3fb46d1ec6badb49e940b479 upstream. net/netfilter/nft_fwd_netdev.c: In function ‘nft_fwd_netdev_eval’: net/netfilter/nft_fwd_netdev.c:32:10: error: ‘struct sk_buff’ has no member named ‘tc_redirected’ pkt->skb->tc_redirected = 1; ^~ net/netfilter/nft_fwd_netdev.c:33:10: error: ‘struct sk_buff’ has no member named ‘tc_from_ingress’ pkt->skb->tc_from_ingress = 1; ^~ To avoid a direct dependency with tc actions from netfilter, wrap the redirect bits around CONFIG_NET_REDIRECT and move helpers to include/linux/skbuff.h. Turn on this toggle from the ifb driver, the only existing client of these bits in the tree. This patch adds skb_set_redirected() that sets on the redirected bit on the skbuff, it specifies if the packet was redirect from ingress and resets the timestamp (timestamp reset was originally missing in the netfilter bugfix). Fixes: bcfabee1afd99484 ("netfilter: nft_fwd_netdev: allow to redirect to ifb via ingress") Reported-by: noreply@ellerman.id.au Reported-by: Geert Uytterhoeven Signed-off-by: Pablo Neira Ayuso Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net_sched: fix ops->bind_class() implementations

2020-02-01T09:34:38+00:00

[ Upstream commit 2e24cd755552350b94a7617617c6877b8cbcb701 ] The current implementations of ops->bind_class() are merely searching for classid and updating class in the struct tcf_result, without invoking either of cl_ops->bind_tcf() or cl_ops->unbind_tcf(). This breaks the design of them as qdisc's like cbq use them to count filters too. This is why syzbot triggered the warning in cbq_destroy_class(). In order to fix this, we have to call cl_ops->bind_tcf() and cl_ops->unbind_tcf() like the filter binding path. This patch does so by refactoring out two helper functions __tcf_bind_filter() and __tcf_unbind_filter(), which are lockless and accept a Qdisc pointer, then teaching each implementation to call them correctly. Note, we merely pass the Qdisc pointer as an opaque pointer to each filter, they only need to pass it down to the helper functions without understanding it at all. Fixes: 07d79fc7d94e ("net_sched: add reverse binding for tc class") Reported-and-tested-by: syzbot+0a0596220218fcb603a8@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+63bdb6006961d8c917c6@syzkaller.appspotmail.com Cc: Jamal Hadi Salim Cc: Jiri Pirko Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net/sched: annotate lockless accesses to qdisc->empty

2020-01-09T09:20:02+00:00

commit 90b2be27bb0e56483f335cc10fb59ec66882b949 upstream. KCSAN reported the following race [1] BUG: KCSAN: data-race in __dev_queue_xmit / net_tx_action read to 0xffff8880ba403508 of 1 bytes by task 21814 on cpu 1: __dev_xmit_skb net/core/dev.c:3389 [inline] __dev_queue_xmit+0x9db/0x1b40 net/core/dev.c:3761 dev_queue_xmit+0x21/0x30 net/core/dev.c:3825 neigh_hh_output include/net/neighbour.h:500 [inline] neigh_output include/net/neighbour.h:509 [inline] ip6_finish_output2+0x873/0xec0 net/ipv6/ip6_output.c:116 __ip6_finish_output net/ipv6/ip6_output.c:142 [inline] __ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175 dst_output include/net/dst.h:436 [inline] ip6_local_out+0x74/0x90 net/ipv6/output_core.c:179 ip6_send_skb+0x53/0x110 net/ipv6/ip6_output.c:1795 udp_v6_send_skb.isra.0+0x3ec/0xa70 net/ipv6/udp.c:1173 udpv6_sendmsg+0x1906/0x1c20 net/ipv6/udp.c:1471 inet6_sendmsg+0x6d/0x90 net/ipv6/af_inet6.c:576 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg+0x9f/0xc0 net/socket.c:657 ___sys_sendmsg+0x2b7/0x5d0 net/socket.c:2311 __sys_sendmmsg+0x123/0x350 net/socket.c:2413 __do_sys_sendmmsg net/socket.c:2442 [inline] __se_sys_sendmmsg net/socket.c:2439 [inline] __x64_sys_sendmmsg+0x64/0x80 net/socket.c:2439 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 write to 0xffff8880ba403508 of 1 bytes by interrupt on cpu 0: qdisc_run_begin include/net/sch_generic.h:160 [inline] qdisc_run include/net/pkt_sched.h:120 [inline] net_tx_action+0x2b1/0x6c0 net/core/dev.c:4551 __do_softirq+0x115/0x33f kernel/softirq.c:292 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082 do_softirq.part.0+0x6b/0x80 kernel/softirq.c:337 do_softirq kernel/softirq.c:329 [inline] __local_bh_enable_ip+0x76/0x80 kernel/softirq.c:189 local_bh_enable include/linux/bottom_half.h:32 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:688 [inline] ip6_finish_output2+0x7bb/0xec0 net/ipv6/ip6_output.c:117 __ip6_finish_output net/ipv6/ip6_output.c:142 [inline] __ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175 dst_output include/net/dst.h:436 [inline] ip6_local_out+0x74/0x90 net/ipv6/output_core.c:179 ip6_send_skb+0x53/0x110 net/ipv6/ip6_output.c:1795 udp_v6_send_skb.isra.0+0x3ec/0xa70 net/ipv6/udp.c:1173 udpv6_sendmsg+0x1906/0x1c20 net/ipv6/udp.c:1471 inet6_sendmsg+0x6d/0x90 net/ipv6/af_inet6.c:576 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg+0x9f/0xc0 net/socket.c:657 ___sys_sendmsg+0x2b7/0x5d0 net/socket.c:2311 __sys_sendmmsg+0x123/0x350 net/socket.c:2413 __do_sys_sendmmsg net/socket.c:2442 [inline] __se_sys_sendmmsg net/socket.c:2439 [inline] __x64_sys_sendmmsg+0x64/0x80 net/socket.c:2439 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 21817 Comm: syz-executor.2 Not tainted 5.4.0-rc6+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: d518d2ed8640 ("net/sched: fix race between deactivation and dequeue for NOLOCK qdisc") Signed-off-by: Eric Dumazet Reported-by: syzbot Cc: Paolo Abeni Cc: Davide Caratti Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net/sched: add delete_empty() to filters and use it in cls_flower

2020-01-04T18:18:46+00:00

[ Upstream commit a5b72a083da197b493c7ed1e5730d62d3199f7d6 ] Revert "net/sched: cls_u32: fix refcount leak in the error path of u32_change()", and fix the u32 refcount leak in a more generic way that preserves the semantic of rule dumping. On tc filters that don't support lockless insertion/removal, there is no need to guard against concurrent insertion when a removal is in progress. Therefore, for most of them we can avoid a full walk() when deleting, and just decrease the refcount, like it was done on older Linux kernels. This fixes situations where walk() was wrongly detecting a non-empty filter, like it happened with cls_u32 in the error path of change(), thus leading to failures in the following tdc selftests: 6aa7: (filter, u32) Add/Replace u32 with source match and invalid indev 6658: (filter, u32) Add/Replace u32 with custom hash table and invalid handle 74c2: (filter, u32) Add/Replace u32 filter with invalid hash table id On cls_flower, and on (future) lockless filters, this check is necessary: move all the check_empty() logic in a callback so that each filter can have its own implementation. For cls_flower, it's sufficient to check if no IDRs have been allocated. This reverts commit 275c44aa194b7159d1191817b20e076f55f0e620. Changes since v1: - document the need for delete_empty() when TCF_PROTO_OPS_DOIT_UNLOCKED is used, thanks to Vlad Buslov - implement delete_empty() without doing fl_walk(), thanks to Vlad Buslov - squash revert and new fix in a single patch, to be nice with bisect tests that run tdc on u32 filter, thanks to Dave Miller Fixes: 275c44aa194b ("net/sched: cls_u32: fix refcount leak in the error path of u32_change()") Fixes: 6676d5e416ee ("net: sched: set dedicated tcf_walker flag when tp is empty") Suggested-by: Jamal Hadi Salim Suggested-by: Vlad Buslov Signed-off-by: Davide Caratti Reviewed-by: Vlad Buslov Tested-by: Jamal Hadi Salim Acked-by: Jamal Hadi Salim Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: sched: prevent duplicate flower rules from tcf_proto destroy race

2019-11-06T01:47:26+00:00

When a new filter is added to cls_api, the function tcf_chain_tp_insert_unique() looks up the protocol/priority/chain to determine if the tcf_proto is duplicated in the chain's hashtable. It then creates a new entry or continues with an existing one. In cls_flower, this allows the function fl_ht_insert_unque to determine if a filter is a duplicate and reject appropriately, meaning that the duplicate will not be passed to drivers via the offload hooks. However, when a tcf_proto is destroyed it is removed from its chain before a hardware remove hook is hit. This can lead to a race whereby the driver has not received the remove message but duplicate flows can be accepted. This, in turn, can lead to the offload driver receiving incorrect duplicate flows and out of order add/delete messages. Prevent duplicates by utilising an approach suggested by Vlad Buslov. A hash table per block stores each unique chain/protocol/prio being destroyed. This entry is only removed when the full destroy (and hardware offload) has completed. If a new flow is being added with the same identiers as a tc_proto being detroyed, then the add request is replayed until the destroy is complete. Fixes: 8b64678e0af8 ("net: sched: refactor tp insert/delete for concurrent execution") Signed-off-by: John Hurley Signed-off-by: Vlad Buslov Reviewed-by: Simon Horman Reported-by: Louis Peens Signed-off-by: David S. Miller

sch_netem: fix rcu splat in netem_enqueue()

2019-09-27T08:29:11+00:00

qdisc_root() use from netem_enqueue() triggers a lockdep warning. __dev_queue_xmit() uses rcu_read_lock_bh() which is not equivalent to rcu_read_lock() + local_bh_disable_bh as far as lockdep is concerned. WARNING: suspicious RCU usage 5.3.0-rc7+ #0 Not tainted ----------------------------- include/net/sch_generic.h:492 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by syz-executor427/8855: #0: 00000000b5525c01 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #0: 00000000b5525c01 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x2dc/0x2570 net/ipv4/ip_output.c:214 #1: 00000000b5525c01 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x20a/0x3650 net/core/dev.c:3804 #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: spin_lock include/linux/spinlock.h:338 [inline] #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: __dev_xmit_skb net/core/dev.c:3502 [inline] #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: __dev_queue_xmit+0x14b8/0x3650 net/core/dev.c:3838 stack backtrace: CPU: 0 PID: 8855 Comm: syz-executor427 Not tainted 5.3.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5357 qdisc_root include/net/sch_generic.h:492 [inline] netem_enqueue+0x1cfb/0x2d80 net/sched/sch_netem.c:479 __dev_xmit_skb net/core/dev.c:3527 [inline] __dev_queue_xmit+0x15d2/0x3650 net/core/dev.c:3838 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902 neigh_hh_output include/net/neighbour.h:500 [inline] neigh_output include/net/neighbour.h:509 [inline] ip_finish_output2+0x1726/0x2570 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:308 [inline] __ip_finish_output+0x5fc/0xb90 net/ipv4/ip_output.c:290 ip_finish_output+0x38/0x1f0 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip_mc_output+0x292/0xf40 net/ipv4/ip_output.c:417 dst_output include/net/dst.h:436 [inline] ip_local_out+0xbb/0x190 net/ipv4/ip_output.c:125 ip_send_skb+0x42/0xf0 net/ipv4/ip_output.c:1555 udp_send_skb.isra.0+0x6b2/0x1160 net/ipv4/udp.c:887 udp_sendmsg+0x1e96/0x2820 net/ipv4/udp.c:1174 inet_sendmsg+0x9e/0xe0 net/ipv4/af_inet.c:807 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:657 ___sys_sendmsg+0x3e2/0x920 net/socket.c:2311 __sys_sendmmsg+0x1bf/0x4d0 net/socket.c:2413 __do_sys_sendmmsg net/socket.c:2442 [inline] __se_sys_sendmmsg net/socket.c:2439 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2439 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller