INFO: task syz-executor.2:9474 blocked for more than 143 seconds. Not tainted 5.15.0-next-20211106-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:27928 pid: 9474 ppid: 6546 flags:0x00024004 Call Trace: context_switch kernel/sched/core.c:4984 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6265 schedule+0xd2/0x260 kernel/sched/core.c:6338 io_uring_cancel_generic+0x53d/0x690 fs/io_uring.c:9850 io_uring_files_cancel include/linux/io_uring.h:16 [inline] do_exit+0x60c/0x2b40 kernel/exit.c:787 do_group_exit+0x125/0x310 kernel/exit.c:929 get_signal+0x47d/0x2220 kernel/signal.c:2830 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fcf10f6bae9 RSP: 002b:00007fcf0e4e1218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fcf1107ef68 RCX: 00007fcf10f6bae9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fcf1107ef68 RBP: 00007fcf1107ef60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fcf1107ef6c R13: 00007fff94e72a0f R14: 00007fcf0e4e1300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb83a60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6236: #0: ffff888072ea7270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.0-next-20211106-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:254 [inline] watchdog+0xcb7/0xed0 kernel/hung_task.c:339 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2958 Comm: systemd-journal Not tainted 5.15.0-next-20211106-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:set_root+0x297/0x5b0 fs/namei.c:942 Code: 00 00 00 00 fc ff df 4c 8b 6b 28 49 8d 7d 08 48 89 f8 48 c1 e8 03 0f b6 04 08 84 c0 74 08 3c 03 0f 8e 9b 02 00 00 45 8b 6d 08 <31> ff 45 89 ef 41 83 e7 01 44 89 fe e8 d8 08 ab ff 45 85 ff 74 71 RSP: 0018:ffffc90001b1fac8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc90001b1fce0 RCX: dffffc0000000000 RDX: ffff88801ab23be8 RSI: ffffffff81ccc3fd RDI: ffff88801ab23bf0 RBP: ffffc90001b1fb40 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff81ccc3be R11: 000000000000002f R12: 0000000000000002 R13: 0000000000000002 R14: ffff88801b10b500 R15: ffff88801b10b550 FS: 00007efcb128a8c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efcae6d8000 CR3: 000000001be77000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: nd_jump_root+0x3c8/0x570 fs/namei.c:961 path_init+0x1020/0x1920 fs/namei.c:2359 path_lookupat+0x30/0x860 fs/namei.c:2439 filename_lookup+0x1c6/0x590 fs/namei.c:2478 user_path_at_empty+0x42/0x60 fs/namei.c:2801 user_path_at include/linux/namei.h:57 [inline] do_faccessat+0x127/0x850 fs/open.c:421 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7efcb05459c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffc5d8a2a88 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffc5d8a5ab0 RCX: 00007efcb05459c7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055b1645fd9a3 RBP: 00007ffc5d8a2bd0 R08: 000055b1645f33e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 000055b1649068a0 R15: 00007ffc5d8a30c0 ---------------- Code disassembly (best guess), 6 bytes skipped: 0: df 4c 8b 6b fisttps 0x6b(%rbx,%rcx,4) 4: 28 49 8d sub %cl,-0x73(%rcx) 7: 7d 08 jge 0x11 9: 48 89 f8 mov %rdi,%rax c: 48 c1 e8 03 shr $0x3,%rax 10: 0f b6 04 08 movzbl (%rax,%rcx,1),%eax 14: 84 c0 test %al,%al 16: 74 08 je 0x20 18: 3c 03 cmp $0x3,%al 1a: 0f 8e 9b 02 00 00 jle 0x2bb 20: 45 8b 6d 08 mov 0x8(%r13),%r13d * 24: 31 ff xor %edi,%edi <-- trapping instruction 26: 45 89 ef mov %r13d,%r15d 29: 41 83 e7 01 and $0x1,%r15d 2d: 44 89 fe mov %r15d,%esi 30: e8 d8 08 ab ff callq 0xffab090d 35: 45 85 ff test %r15d,%r15d 38: 74 71 je 0xab