INFO: task kworker/0:3:5863 blocked for more than 143 seconds. Not tainted 6.15.0-syzkaller-12426-ge271ed52b344 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:3 state:D stack:26264 pid:5863 tgid:5863 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events p9_write_work Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747 anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 __kernel_write_iter+0x317/0xa90 fs/read_write.c:619 __kernel_write fs/read_write.c:639 [inline] kernel_write fs/read_write.c:660 [inline] kernel_write+0x1f4/0x6c0 fs/read_write.c:650 p9_fd_write net/9p/trans_fd.c:434 [inline] p9_write_work+0x258/0xc10 net/9p/trans_fd.c:485 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 3 locks held by kworker/0:0/9: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc900000e7d10 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88805a5a4c68 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 3 locks held by kworker/0:1/10: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc900000f7d10 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88805c3a0c68 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 3 locks held by kworker/1:0/24: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc900001e7d10 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff8880357d5468 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 1 lock held by khungtaskd/31: #0: ffffffff8e5c4cc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c4cc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c4cc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 3 locks held by kworker/1:1/43: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90000b37d10 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88802dc51068 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 3 locks held by kworker/0:2/972: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc900039dfd10 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88805faa7c68 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 3 locks held by kworker/1:2/1588: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90004d9fd10 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff888036020868 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 2 locks held by getty/5583: #0: ffff8880371d20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by kworker/0:3/5863: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000450fd10 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88805abe7c68 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 2 locks held by syz.0.16/6632: #0: ffff88805abe7c68 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 #1: ffff888059c902e8 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline] #1: ffff888059c902e8 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_fault+0x61d/0x26c0 mm/filemap.c:3419 2 locks held by syz.1.18/6812: #0: ffff88805faa7c68 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 #1: ffff888059c90958 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline] #1: ffff888059c90958 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_fault+0x61d/0x26c0 mm/filemap.c:3419 3 locks held by kworker/0:5/6813: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90003307d10 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88805b6d5468 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 3 locks held by kworker/0:6/6835: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000213fd10 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff888023b7ec68 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 2 locks held by syz.2.19/6837: #0: ffff888023b7ec68 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 #1: ffff888059c90fc8 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline] #1: ffff888059c90fc8 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_fault+0x61d/0x26c0 mm/filemap.c:3419 2 locks held by syz.3.20/6864: #0: ffff8880357d5468 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 #1: ffff888072630958 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline] #1: ffff888072630958 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_fault+0x61d/0x26c0 mm/filemap.c:3419 2 locks held by syz.4.21/6896: #0: ffff88805c3a0c68 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 #1: ffff888059c91638 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline] #1: ffff888059c91638 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_fault+0x61d/0x26c0 mm/filemap.c:3419 2 locks held by syz.5.22/6926: #0: ffff88805a5a4c68 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 #1: ffff888059c91ca8 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline] #1: ffff888059c91ca8 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_fault+0x61d/0x26c0 mm/filemap.c:3419 2 locks held by syz.6.23/6957: #0: ffff88802dc51068 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 #1: ffff888072630fc8 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline] #1: ffff888072630fc8 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_fault+0x61d/0x26c0 mm/filemap.c:3419 2 locks held by syz.7.24/6992: #0: ffff888036020868 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 #1: ffff888072631638 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline] #1: ffff888072631638 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_fault+0x61d/0x26c0 mm/filemap.c:3419 3 locks held by kworker/1:7/7021: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000520fd10 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88807d8c5868 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 2 locks held by syz.8.26/7025: #0: ffff88807d8c5868 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 #1: ffff888072632318 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline] #1: ffff888072632318 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_fault+0x61d/0x26c0 mm/filemap.c:3419 2 locks held by syz.9.27/7056: #0: ffff88805b6d5468 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:458 #1: ffff888059c92318 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline] #1: ffff888059c92318 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_fault+0x61d/0x26c0 mm/filemap.c:3419 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-syzkaller-12426-ge271ed52b344 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-syzkaller-12426-ge271ed52b344 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 1b 73 02 e9 03 fb 02 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 23 f0 2a 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e207e08 EFLAGS: 000002c6 RAX: 0000000000188a85 RBX: 0000000000000000 RCX: ffffffff8b7f1c99 RDX: 0000000000000000 RSI: ffffffff8de14dcb RDI: ffffffff8c157060 RBP: fffffbfff1c52ef0 R08: 0000000000000001 R09: ffffed1017086645 R10: ffff8880b843322b R11: 0000000000000001 R12: 0000000000000000 R13: ffffffff8e297780 R14: ffffffff90a80050 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812475a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f2d19cdbe0 CR3: 000000000e382000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:743 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 rest_init+0x16b/0x2b0 init/main.c:744 start_kernel+0x3ee/0x4d0 init/main.c:1101 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x148