INFO: task udevd:5217 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24936 pid:5217 tgid:5217 ppid:1 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760 bdev_open+0x41a/0xe40 block/bdev.c:945 blkdev_open+0x277/0x3f0 block/fops.c:691 do_dentry_open+0x982/0x1530 fs/open.c:965 vfs_open+0x82/0x3f0 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x1de4/0x2cb0 fs/namei.c:4046 do_filp_open+0x20b/0x470 fs/namei.c:4073 do_sys_openat2+0x11b/0x1d0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faf4e2a7407 RSP: 002b:00007ffdbf364690 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007faf4ea10880 RCX: 00007faf4e2a7407 RDX: 00000000000a0800 RSI: 0000563d70263640 RDI: ffffffffffffff9c RBP: 0000563d70277bb0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 0000563d40690100 R14: 0000000000000000 R15: 00007ffdbf364920 INFO: task syz.5.9262:3338 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.9262 state:D stack:28624 pid:3338 tgid:3337 ppid:2549 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760 bdev_release+0x15a/0x6d0 block/bdev.c:1128 blkdev_release+0x15/0x20 block/fops.c:699 __fput+0x3ff/0xb70 fs/file_table.c:468 task_work_run+0x14d/0x240 kernel/task_work.c:227 get_signal+0x1d1/0x26d0 kernel/signal.c:2807 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f734158ebe9 RSP: 002b:00007f734235b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f73417b5fa0 RCX: 00007f734158ebe9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f7341611e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f73417b6038 R14: 00007f73417b5fa0 R15: 00007ffd40b36cf8 INFO: lockdep is turned off. NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6853 Comm: syz.8.10637 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x8/0x20 kernel/kcov.c:300 Code: bf 06 00 00 00 e9 b8 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 0c 24 <40> 0f b6 d6 40 0f b6 f7 bf 01 00 00 00 e9 86 fe ff ff 66 0f 1f 44 RSP: 0018:ffffc9000fad7bc8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81a8520a RDX: ffff888069010000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000010 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000010 R11: ffffffff9b0cf058 R12: 0000000000000001 R13: ffffc9000fad7d78 R14: 0000000000000000 R15: ffff8880b8527d00 FS: 00005555639c6500(0000) GS:ffff8881247bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055559007d608 CR3: 000000004a028000 CR4: 00000000003526f0 Call Trace: hrtimer_start_range_ns+0x9ba/0xfc0 kernel/time/hrtimer.c:1329 hrtimer_start_expires include/linux/hrtimer.h:277 [inline] hrtimer_sleeper_start_expires kernel/time/hrtimer.c:2023 [inline] do_nanosleep+0x1f7/0x570 kernel/time/hrtimer.c:2097 hrtimer_nanosleep+0x155/0x380 kernel/time/hrtimer.c:2147 common_nsleep+0xa1/0xd0 kernel/time/posix-timers.c:1353 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1399 [inline] __se_sys_clock_nanosleep kernel/time/posix-timers.c:1376 [inline] __x64_sys_clock_nanosleep+0x34d/0x4a0 kernel/time/posix-timers.c:1376 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7b39bc14a5 Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 54 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f 55 ff ff 48 8b 04 24 48 83 c4 28 f7 d8 RSP: 002b:00007fffad5482e0 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 00007f7b39db5fa0 RCX: 00007f7b39bc14a5 RDX: 00007fffad548320 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f7b39db7da0 R08: 0000000000000000 R09: 00007f7b3a946000 R10: 0000000000000000 R11: 0000000000000293 R12: 00000000001842a9 R13: 00007fffad548440 R14: ffffffffffffffff R15: 00007fffad548460