INFO: task syz-executor.5:11665 can't die for more than 143 seconds. syz-executor.5 R running task 29264 11665 7558 0x00004006 Call Trace: Showing all locks held in the system: 1 lock held by khungtaskd/1166: #0: ffffffff899befc0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5754 1 lock held by in:imklog/6773: #0: ffff8880a9395930 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 1 lock held by syz-executor.5/11665: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1166 Comm: khungtaskd Not tainted 5.7.0-rc1-next-20200415-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:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:249 [inline] watchdog+0xde3/0x14e0 kernel/hung_task.c:333 kthread+0x388/0x470 kernel/kthread.c:268 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: 11665 Comm: syz-executor.5 Not tainted 5.7.0-rc1-next-20200415-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:hlock_class kernel/locking/lockdep.c:174 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3146 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3202 [inline] RIP: 0010:__lock_acquire+0x2163/0x4c50 kernel/locking/lockdep.c:4355 Code: fb ff ff 48 b8 00 00 00 00 00 fc ff df 48 8b 54 24 30 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e c1 27 00 00 0f b7 5d 20 <66> 81 e3 ff 1f 0f b7 db be 08 00 00 00 48 89 d8 48 c1 f8 06 48 8d RSP: 0018:ffffc900017279a8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 00000000000004eb RCX: ffffffff81592b4b RDX: 1ffff1100a5a5d9e RSI: 0000000000000008 RDI: ffffffff8c34c728 RBP: ffff888052d2ecd0 R08: 0000000000000001 R09: fffffbfff1862750 R10: ffffffff8c313a7f R11: fffffbfff186274f R12: ffff888052d2e400 R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8a8b8010 FS: 00007f786b38c700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3e8c97c000 CR3: 00000000923d0000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 __mutex_lock_common kernel/locking/mutex.c:956 [inline] __mutex_lock+0x156/0x13c0 kernel/locking/mutex.c:1103 pipe_lock_nested fs/pipe.c:66 [inline] pipe_double_lock+0x1a0/0x1e0 fs/pipe.c:104 splice_pipe_to_pipe fs/splice.c:1562 [inline] do_splice+0x377/0x1560 fs/splice.c:1141 __do_sys_splice fs/splice.c:1447 [inline] __se_sys_splice fs/splice.c:1427 [inline] __x64_sys_splice+0x2c1/0x330 fs/splice.c:1427 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 Code: 0d b7 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f786b38bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00000000005079c0 RCX: 000000000045ca29 RDX: 0000000000000007 RSI: 0000000000000000 RDI: 0000000000000009 RBP: 000000000078c040 R08: ffffffffffff8001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000bae R14: 00000000004ce9f7 R15: 00007f786b38c6d4