================================ WARNING: inconsistent lock state 5.9.0-rc5-next-20200916-syzkaller #0 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-R} usage. syz-executor.1/17568 [HC0[0]:SC1[1]:HE0:SE0] takes: ffff8880a72cfe28 (&s->seqcount#10){+.+-}-{0:0}, at: xfrm_policy_lookup_inexact_addr+0x57/0x200 net/xfrm/xfrm_policy.c:1909 {SOFTIRQ-ON-W} state was registered at: lock_acquire+0x1f2/0xaa0 kernel/locking/lockdep.c:5398 write_seqcount_t_begin_nested include/linux/seqlock.h:509 [inline] write_seqcount_t_begin include/linux/seqlock.h:535 [inline] write_seqlock include/linux/seqlock.h:883 [inline] xfrm_set_spdinfo+0x302/0x660 net/xfrm/xfrm_user.c:1185 xfrm_user_rcv_msg+0x414/0x700 net/xfrm/xfrm_user.c:2684 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2470 xfrm_netlink_rcv+0x6b/0x90 net/xfrm/xfrm_user.c:2692 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:671 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2362 ___sys_sendmsg+0xf3/0x170 net/socket.c:2416 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2449 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 irq event stamp: 257 hardirqs last enabled at (256): [] seqcount_lockdep_reader_access+0x14b/0x1a0 include/linux/seqlock.h:105 hardirqs last disabled at (257): [] seqcount_lockdep_reader_access+0x11b/0x1a0 include/linux/seqlock.h:102 softirqs last enabled at (226): [] ipt_do_table+0xcc6/0x1870 net/ipv4/netfilter/ip_tables.c:355 softirqs last disabled at (235): [] asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:786 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&s->seqcount#10); lock(&s->seqcount#10); *** DEADLOCK *** 5 locks held by syz-executor.1/17568: #0: ffff8880615f2760 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1581 [inline] #0: ffff8880615f2760 (sk_lock-AF_INET){+.+.}-{0:0}, at: raw_sendmsg+0xa7c/0x2d40 net/ipv4/raw.c:666 #1: ffffffff89e71cc0 (rcu_read_lock){....}-{1:2}, at: __skb_unlink include/linux/skbuff.h:2067 [inline] #1: ffffffff89e71cc0 (rcu_read_lock){....}-{1:2}, at: __skb_dequeue include/linux/skbuff.h:2082 [inline] #1: ffffffff89e71cc0 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x270/0x8e0 net/core/dev.c:6284 #2: ffffffff89e71cc0 (rcu_read_lock){....}-{1:2}, at: __skb_pull include/linux/skbuff.h:2298 [inline] #2: ffffffff89e71cc0 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x124/0x370 net/ipv4/ip_input.c:228 #3: ffffffff8ab99378 (raw_v4_hashinfo.lock){++.-}-{2:2}, at: raw_v4_input net/ipv4/raw.c:178 [inline] #3: ffffffff8ab99378 (raw_v4_hashinfo.lock){++.-}-{2:2}, at: raw_local_deliver+0x285/0xbd0 net/ipv4/raw.c:218 #4: ffffffff89e71cc0 (rcu_read_lock){....}-{1:2}, at: xfrm_policy_lookup_bytype+0x104/0xa40 net/xfrm/xfrm_policy.c:2082 stack backtrace: CPU: 0 PID: 17568 Comm: syz-executor.1 Not tainted 5.9.0-rc5-next-20200916-syzkaller #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+0x198/0x1fb lib/dump_stack.c:118 print_usage_bug kernel/locking/lockdep.c:3694 [inline] valid_state kernel/locking/lockdep.c:3705 [inline] mark_lock_irq kernel/locking/lockdep.c:3908 [inline] mark_lock.cold+0x13/0x10d kernel/locking/lockdep.c:4375 mark_usage kernel/locking/lockdep.c:4252 [inline] __lock_acquire+0x1402/0x55d0 kernel/locking/lockdep.c:4750 lock_acquire+0x1f2/0xaa0 kernel/locking/lockdep.c:5398 seqcount_lockdep_reader_access+0x139/0x1a0 include/linux/seqlock.h:103 xfrm_policy_lookup_inexact_addr+0x57/0x200 net/xfrm/xfrm_policy.c:1909 xfrm_policy_find_inexact_candidates+0xac/0x1d0 net/xfrm/xfrm_policy.c:1953 xfrm_policy_lookup_bytype+0x4b8/0xa40 net/xfrm/xfrm_policy.c:2108 xfrm_policy_lookup net/xfrm/xfrm_policy.c:2144 [inline] __xfrm_policy_check+0x110e/0x2650 net/xfrm/xfrm_policy.c:3572 __xfrm_policy_check2 include/net/xfrm.h:1097 [inline] xfrm_policy_check include/net/xfrm.h:1106 [inline] xfrm4_policy_check include/net/xfrm.h:1111 [inline] raw_rcv+0x340/0x500 net/ipv4/raw.c:331 raw_v4_input net/ipv4/raw.c:196 [inline] raw_local_deliver+0x7c8/0xbd0 net/ipv4/raw.c:218 ip_protocol_deliver_rcu+0x88/0x880 net/ipv4/ip_input.c:193 ip_local_deliver_finish+0x20a/0x370 net/ipv4/ip_input.c:231 NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] ip_local_deliver+0x1b3/0x200 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:449 [inline] ip_rcv_finish+0x1da/0x2f0 net/ipv4/ip_input.c:428 NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] ip_rcv+0xaa/0xd0 net/ipv4/ip_input.c:539 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5287 __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5401 process_backlog+0x2e1/0x8e0 net/core/dev.c:6286 napi_poll net/core/dev.c:6730 [inline] net_rx_action+0x572/0x1300 net/core/dev.c:6800 __do_softirq+0x202/0xa42 kernel/softirq.c:298 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:786 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] do_softirq_own_stack+0x9d/0xd0 arch/x86/kernel/irq_64.c:77 do_softirq kernel/softirq.c:343 [inline] do_softirq+0x154/0x1b0 kernel/softirq.c:330 netif_rx_ni+0x33d/0x590 net/core/dev.c:4836 dev_loopback_xmit+0x204/0x590 net/core/dev.c:3852 ip_mc_finish_output+0x16d/0x490 net/ipv4/ip_output.c:357 NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] ip_mc_output+0x624/0x700 net/ipv4/ip_output.c:396 dst_output include/net/dst.h:443 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] ip_send_skb net/ipv4/ip_output.c:1568 [inline] ip_push_pending_frames+0x125/0x2b0 net/ipv4/ip_output.c:1588 raw_sendmsg+0x130e/0x2d40 net/ipv4/raw.c:673 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:817 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:671 __sys_sendto+0x21c/0x320 net/socket.c:1992 __do_sys_sendto net/socket.c:2004 [inline] __se_sys_sendto net/socket.c:2000 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2000 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d5f9 Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fb501908c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000000000002d4c0 RCX: 000000000045d5f9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000118cf98 R08: 0000000020000d00 R09: 000000000000006e R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffd18f02a5f R14: 00007fb5019099c0 R15: 000000000118cf4c