syzbot

INFO: task kworker/0:0:9 blocked for more than 143 seconds.
      Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:0     state:D stack:28008 pid:9     tgid:9     ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: events p9_write_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x116f/0x5de0 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6860
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
 __mutex_lock_common kernel/locking/mutex.c:678 [inline]
 __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:746
 anon_pipe_write+0x15d/0x1a70 fs/pipe.c:459
 __kernel_write_iter+0x317/0xa90 fs/read_write.c:617
 __kernel_write fs/read_write.c:637 [inline]
 kernel_write fs/read_write.c:658 [inline]
 kernel_write+0x1f4/0x6c0 fs/read_write.c:648
 p9_fd_write net/9p/trans_fd.c:434 [inline]
 p9_write_work+0x258/0xc10 net/9p/trans_fd.c:485
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/9:
 #0: ffff88801b478d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc900000e7d18 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffff88801e693868 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:459
1 lock held by khungtaskd/31:
 #0: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764
2 locks held by getty/5570:
 #0: ffff8880366aa0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
2 locks held by syz-executor186/5807:
 #0: ffff88801e693868 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1a70 fs/pipe.c:459
 #1: ffff8880783182e8 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:922 [inline]
 #1: ffff8880783182e8 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_fault+0x625/0x2740 mm/filemap.c:3410

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call Trace:
 <TASK>
 __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:274 [inline]
 watchdog+0xf70/0x12c0 kernel/hung_task.c:437
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:lockdep_hardirqs_off+0x2f/0xf0 kernel/locking/lockdep.c:4506
Code: 0d aa ed 18 05 85 c9 0f 84 ad 00 00 00 55 53 48 89 fb 65 8b 05 12 8e 37 08 a9 00 00 f0 00 74 3a 8b 15 b5 e3 46 0f 85 d2 74 12 <65> 8b 05 16 c8 37 08 85 c0 75 43 5b 5d c3 cc cc cc cc 9c 58 f6 c4
RSP: 0018:ffffc90000127908 EFLAGS: 00000046
RAX: 0000000000000046 RBX: ffffffff815e99f3 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8dbdf8f1 RDI: ffffffff8bf47de0
RBP: ffffffff82164c58 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000c5c
R13: ffffea0000085900 R14: ffffffffffffffff R15: 8000000000000063
FS:  0000000000000000(0000) GS:ffff8881249e4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005595aa62c028 CR3: 000000000e180000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 trace_hardirqs_off+0xd/0x40 kernel/trace/trace_preemptirq.c:104
 __text_poke+0x873/0xd00 arch/x86/kernel/alternative.c:2276
 text_poke_bp_batch+0x3e6/0x760 arch/x86/kernel/alternative.c:2687
 text_poke_flush arch/x86/kernel/alternative.c:2856 [inline]
 text_poke_flush arch/x86/kernel/alternative.c:2853 [inline]
 text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2863
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 jump_label_update+0x376/0x550 kernel/jump_label.c:919
 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate mm/kfence/core.c:850 [inline]
 toggle_allocation_gate+0xfa/0x280 mm/kfence/core.c:842
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>