INFO: task syz-executor.1:28248 blocked for more than 143 seconds. Not tainted 5.6.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D25592 28248 7171 0x00004004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4154 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4213 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 nfnl_lock net/netfilter/nfnetlink.c:62 [inline] nfnetlink_rcv_msg+0x9a6/0xf30 net/netfilter/nfnetlink.c:224 netlink_rcv_skb+0x15a/0x410 net/netlink/af_netlink.c:2469 nfnetlink_rcv+0x1ac/0x420 net/netfilter/nfnetlink.c:563 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 sock_no_sendpage+0xf8/0x140 net/core/sock.c:2751 kernel_sendpage+0x82/0xd0 net/socket.c:3791 sock_sendpage+0x84/0xa0 net/socket.c:950 pipe_to_sendpage+0x2aa/0x380 fs/splice.c:458 splice_from_pipe_feed fs/splice.c:512 [inline] __splice_from_pipe+0x3e6/0x7b0 fs/splice.c:636 splice_from_pipe+0xd9/0x140 fs/splice.c:671 do_splice_from fs/splice.c:863 [inline] direct_splice_actor+0x115/0x160 fs/splice.c:1037 splice_direct_to_actor+0x38c/0x980 fs/splice.c:992 do_splice_direct+0x1a8/0x270 fs/splice.c:1080 do_sendfile+0x549/0xc40 fs/read_write.c:1520 __do_sys_sendfile64 fs/read_write.c:1581 [inline] __se_sys_sendfile64 fs/read_write.c:1567 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1567 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c849 Code: Bad RIP value. RSP: 002b:00007f94be33ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f94be33f6d4 RCX: 000000000045c849 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000100000001 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008d4 R14: 00000000004cb786 R15: 000000000076bf0c Showing all locks held in the system: 1 lock held by khungtaskd/1117: #0: ffffffff899accc0 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5331 1 lock held by in:imklog/6706: #0: ffff8880a7db6120 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:826 2 locks held by syz-executor.5/28210: 1 lock held by syz-executor.1/28248: #0: ffffffff8d163d70 (&table[i].mutex){+.+.}, at: nfnl_lock net/netfilter/nfnetlink.c:62 [inline] #0: ffffffff8d163d70 (&table[i].mutex){+.+.}, at: nfnetlink_rcv_msg+0x9a6/0xf30 net/netfilter/nfnetlink.c:224 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1117 Comm: khungtaskd Not tainted 5.6.0-rc7-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+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa8c/0x1010 kernel/hung_task.c:289 kthread+0x357/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4102 Comm: systemd-journal Not tainted 5.6.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:do_audit_syscall_entry arch/x86/entry/common.c:55 [inline] RIP: 0010:syscall_trace_enter+0x31d/0xd10 arch/x86/entry/common.c:127 Code: 00 0f 85 b0 08 00 00 4d 8b 3f 31 ff 49 c1 ef 1c 41 83 e7 01 4c 89 fe e8 11 a6 71 00 4d 85 ff 0f 85 98 04 00 00 e8 73 a4 71 00 <48> 8b 54 24 08 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 RSP: 0018:ffffc90001647e30 EFLAGS: 00000293 RAX: ffff888093276540 RBX: ffffc90001647f58 RCX: ffffffff810089ef RDX: 0000000000000000 RSI: ffffffff810089fd RDI: 0000000000000007 RBP: 00000000c000003e R08: ffff888093276540 R09: ffffed101264eca9 R10: ffffed101264eca8 R11: ffff888093276547 R12: 1ffff920002c8fca R13: 0000000000000000 R14: ffffc90001647fd0 R15: 0000000000000000 FS: 00007fb3667688c0(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb363bf9018 CR3: 000000009438a000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: do_syscall_64+0x504/0x7d0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fb365cf8210 Code: 73 01 c3 48 8b 0d 98 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d b9 c1 20 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 4e fc ff ff 48 89 04 24 RSP: 002b:00007ffe1d813428 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007ffe1d815ea0 RCX: 00007fb365cf8210 RDX: 0000000000002000 RSI: 00007ffe1d813ca0 RDI: 0000000000000009 RBP: 0000000000000000 R08: 0000000000000008 R09: 0000000000000321 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe1d813ca0 R13: 00007ffe1d815df8 R14: 0000556608bcc958 R15: 0005a1e2d8c32871