INFO: task iou-wrk-19835:19892 blocked for more than 143 seconds. Not tainted 5.15.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:iou-wrk-19835 state:D stack:27952 pid:19892 ppid: 6558 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xb44/0x5960 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x176/0x280 kernel/sched/completion.c:138 io_worker_exit fs/io-wq.c:183 [inline] io_wqe_worker+0x66d/0xc40 fs/io-wq.c:597 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8b981ae0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 1 lock held by in:imklog/6213: #0: ffff88801a912af0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by rs:main Q:Reg/6215: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.0-rc5-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:210 [inline] watchdog+0xc1d/0xf50 kernel/hung_task.c:295 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6213 Comm: in:imklog Not tainted 5.15.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_kcov_mode+0x2c/0x40 kernel/kcov.c:174 Code: 05 39 20 8b 7e 89 c2 81 e2 00 01 00 00 a9 00 01 ff 00 74 10 31 c0 85 d2 74 15 8b 96 64 15 00 00 85 d2 74 0b 8b 86 40 15 00 00 <39> f8 0f 94 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 31 c0 RSP: 0018:ffffc9000ade76b8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88807a233900 RDX: 0000000000000000 RSI: ffff88807a233900 RDI: 0000000000000003 RBP: ffffc9000ade77e8 R08: 0000000000000001 R09: 0000000000000000 R10: ffffffff83f6beec R11: 0000000000000001 R12: ffffc9000ade7a5a R13: ffffffff898cbaa6 R14: 1ffff920015bcedd R15: ffffc9000ade7880 FS: 00007fb874fad700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3db24c9000 CR3: 000000006f962000 CR4: 0000000000350ef0 Call Trace: write_comp_data kernel/kcov.c:218 [inline] __sanitizer_cov_trace_const_cmp1+0x22/0x80 kernel/kcov.c:270 format_decode+0xcc/0xad0 lib/vsprintf.c:2510 vsnprintf+0x157/0x14f0 lib/vsprintf.c:2749 sprintf+0xc0/0x100 lib/vsprintf.c:2999 print_time kernel/printk/printk.c:1261 [inline] info_print_prefix+0x248/0x340 kernel/printk/printk.c:1287 record_print_text+0x14d/0x3e0 kernel/printk/printk.c:1336 syslog_print+0x48c/0x580 kernel/printk/printk.c:1536 do_syslog.part.0+0x202/0x640 kernel/printk/printk.c:1655 do_syslog+0x49/0x60 kernel/printk/printk.c:1640 kmsg_read+0x90/0xb0 fs/proc/kmsg.c:40 pde_read fs/proc/inode.c:311 [inline] proc_reg_read+0x119/0x300 fs/proc/inode.c:321 vfs_read+0x1b5/0x600 fs/read_write.c:483 ksys_read+0x12d/0x250 fs/read_write.c:623 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: 0033:0x7fb8775f022d Code: 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 b8 00 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 97 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007fb874f8c580 EFLAGS: 00000293 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb8775f022d RDX: 0000000000001fa0 RSI: 00007fb874f8cda0 RDI: 0000000000000004 RBP: 000055ec796899d0 R08: 0000000000000000 R09: 0000000000000000 R10: 2ce33e6c02ce33e7 R11: 0000000000000293 R12: 00007fb874f8cda0 R13: 0000000000001fa0 R14: 0000000000001f9f R15: 00007fb874f8ce5c ---------------- Code disassembly (best guess): 0: 05 39 20 8b 7e add $0x7e8b2039,%eax 5: 89 c2 mov %eax,%edx 7: 81 e2 00 01 00 00 and $0x100,%edx d: a9 00 01 ff 00 test $0xff0100,%eax 12: 74 10 je 0x24 14: 31 c0 xor %eax,%eax 16: 85 d2 test %edx,%edx 18: 74 15 je 0x2f 1a: 8b 96 64 15 00 00 mov 0x1564(%rsi),%edx 20: 85 d2 test %edx,%edx 22: 74 0b je 0x2f 24: 8b 86 40 15 00 00 mov 0x1540(%rsi),%eax * 2a: 39 f8 cmp %edi,%eax <-- trapping instruction 2c: 0f 94 c0 sete %al 2f: c3 retq 30: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 37: 00 00 00 00 3b: 0f 1f 00 nopl (%rax) 3e: 31 c0 xor %eax,%eax