INFO: task kworker/u8:22:27594 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:22 state:D stack:20904 pid:27594 tgid:27594 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-7:7) Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1480/0x50a0 kernel/sched/core.c:6855 __schedule_loop kernel/sched/core.c:6937 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7233 rt_mutex_slowlock_block+0x5ba/0x6d0 kernel/locking/rtmutex.c:1647 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline] rt_mutex_slowlock+0x2a8/0x6b0 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline] mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:552 jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138 write_inode fs/fs-writeback.c:1582 [inline] __writeback_single_inode+0x7e4/0x1240 fs/fs-writeback.c:1802 writeback_sb_inodes+0x8c8/0x1840 fs/fs-writeback.c:2030 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2107 wb_writeback+0x43f/0xaa0 fs/fs-writeback.c:2218 wb_check_start_all fs/fs-writeback.c:2344 [inline] wb_do_writeback fs/fs-writeback.c:2370 [inline] wb_workfn+0x8f3/0xee0 fs/fs-writeback.c:2403 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 INFO: task syz.2.3332:29328 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.3332 state:D stack:25768 pid:29328 tgid:29327 ppid:27309 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1480/0x50a0 kernel/sched/core.c:6855 __schedule_loop kernel/sched/core.c:6937 [inline] schedule+0x165/0x360 kernel/sched/core.c:6952 wb_wait_for_completion+0x360/0x680 fs/fs-writeback.c:226 sync_inodes_sb+0x1cb/0xb80 fs/fs-writeback.c:2894 __iterate_supers+0x13d/0x290 fs/super.c:924 ksys_sync+0x94/0x150 fs/sync.c:102 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0e6286f749 RSP: 002b:00007f0e60ace038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f0e62ac5fa0 RCX: 00007f0e6286f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f0e62ac5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0e62ac6038 R14: 00007f0e62ac5fa0 R15: 00007ffc5f3706f8 INFO: lockdep is turned off. NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf3c/0xf80 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 11459 Comm: kworker/0:11 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_power_efficient wg_ratelimiter_gc_entries RIP: 0010:rt_mutex_has_waiters kernel/locking/rtmutex_common.h:113 [inline] RIP: 0010:rt_mutex_slowunlock+0x117/0x8a0 kernel/locking/rtmutex.c:1452 Code: f7 48 8b 03 48 83 e0 fe 65 48 8b 0c 25 08 d0 a9 91 48 39 c8 0f 85 87 05 00 00 49 8d 5d 40 48 89 d8 48 c1 e8 03 42 80 3c 20 00 <74> 08 48 89 df e8 9f 85 5e f7 48 83 3b 00 0f 84 3e 03 00 00 48 c7 RSP: 0000:ffffc9001f01f8e0 EFLAGS: 00000046 RAX: 1ffffffff1bfc10c RBX: ffffffff8dfe0860 RCX: ffff88802f368000 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc9001f01f7c0 RBP: ffffc9001f01f9d8 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52003e03ef8 R12: dffffc0000000000 R13: ffffffff8dfe0820 R14: 0000000000000a02 R15: 1ffff92003e03f24 FS: 0000000000000000(0000) GS:ffff888126d83000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe8390a6000 CR3: 000000007b628000 CR4: 00000000003526f0 Call Trace: spin_unlock include/linux/spinlock_rt.h:105 [inline] wg_ratelimiter_gc_entries+0x3a8/0x480 drivers/net/wireguard/ratelimiter.c:76 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246