syzbot


WARNING in enqueue_task

Status: upstream: reported on 2025/10/03 00:09
Reported-by: syzbot+bc0e7f4c96fb18d0ac22@syzkaller.appspotmail.com
First crash: 60d, last: 60d

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4262 at mm/maccess.c:226 copy_from_user_nofault+0x160/0x1c0 mm/maccess.c:226
Modules linked in:
CPU: 1 PID: 4262 Comm: kworker/u4:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events_unbound linkwatch_event
RIP: 0010:copy_from_user_nofault+0x160/0x1c0 mm/maccess.c:226

======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
kworker/u4:5/4262 is trying to acquire lock:
ffffffff8c1110c0 (console_owner){..-.}-{0:0}, at: console_trylock_spinning+0x150/0x350 kernel/printk/printk.c:1879

but task is already holding lock:
ffff8880b91280d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:946

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #5 (&base->lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
       lock_timer_base+0x123/0x270 kernel/time/timer.c:946
       __mod_timer+0x117/0xd20 kernel/time/timer.c:1019
       queue_delayed_work_on+0x126/0x1e0 kernel/workqueue.c:1715
       psi_enqueue kernel/sched/stats.h:102 [inline]
       enqueue_task+0x26d/0x2b0 kernel/sched/core.c:1992
       activate_task kernel/sched/core.c:2024 [inline]
       wake_up_new_task+0x442/0x9a0 kernel/sched/core.c:4541
       kernel_clone+0x421/0x930 kernel/fork.c:2703
       kernel_thread+0xc8/0x120 kernel/fork.c:2731
       rest_init+0x21/0x330 init/main.c:706
       start_kernel+0x486/0x530 init/main.c:1140
       secondary_startup_64_no_verify+0xb1/0xbb

-> #4 (&rq->__lock){-.-.}-{2:2}:
       _raw_spin_lock_nested+0x2e/0x40 kernel/locking/spinlock.c:368
       raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
       raw_spin_rq_lock kernel/sched/sched.h:1326 [inline]
       rq_lock kernel/sched/sched.h:1621 [inline]
       task_fork_fair+0x5c/0x350 kernel/sched/fair.c:11499
       sched_cgroup_fork+0x2c6/0x320 kernel/sched/core.c:4485
       copy_process+0x22d1/0x3e00 kernel/fork.c:2395
       kernel_clone+0x219/0x930 kernel/fork.c:2679
       kernel_thread+0xc8/0x120 kernel/fork.c:2731
       rest_init+0x21/0x330 init/main.c:706
       start_kernel+0x486/0x530 init/main.c:1140
       secondary_startup_64_no_verify+0xb1/0xbb

-> #3 (&p->pi_lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
       try_to_wake_up+0x5c/0x1050 kernel/sched/core.c:4049
       __wake_up_common+0x2a4/0x4e0 kernel/sched/wait.c:108
       __wake_up_common_lock kernel/sched/wait.c:138 [inline]
       __wake_up+0x108/0x180 kernel/sched/wait.c:157
       tty_port_default_wakeup+0xa5/0xf0 drivers/tty/tty_port.c:51
       serial8250_tx_chars+0x629/0x830 drivers/tty/serial/8250/8250_port.c:1828
       serial8250_handle_irq+0x519/0x610 drivers/tty/serial/8250/8250_port.c:1924
       serial8250_default_handle_irq+0xb4/0x1a0 drivers/tty/serial/8250/8250_port.c:1941
       serial8250_interrupt+0x9b/0x1c0 drivers/tty/serial/8250/8250_core.c:127
       __handle_irq_event_percpu+0x291/0x9b0 kernel/irq/handle.c:156
       handle_irq_event_percpu kernel/irq/handle.c:196 [inline]
       handle_irq_event+0xa5/0x220 kernel/irq/handle.c:213
       handle_edge_irq+0x243/0xb20 kernel/irq/chip.c:819
       generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
       handle_irq arch/x86/kernel/irq.c:233 [inline]
       __common_interrupt+0xd7/0x1e0 arch/x86/kernel/irq.c:252
       common_interrupt+0xb0/0xd0 arch/x86/kernel/irq.c:242
       asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667
       PageKsm include/linux/page-flags.h:523 [inline]
       do_wp_page+0x48b/0xad0 mm/memory.c:3342
       handle_pte_fault mm/memory.c:4668 [inline]
       __handle_mm_fault mm/memory.c:4785 [inline]
       handle_mm_fault+0x1eca/0x43c0 mm/memory.c:4883
       do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1357
       handle_page_fault arch/x86/mm/fault.c:1445 [inline]
       exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1501
       asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606

-> #2 (&tty->write_wait){-...}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
       __wake_up_common_lock kernel/sched/wait.c:137 [inline]
       __wake_up+0xed/0x180 kernel/sched/wait.c:157
       tty_port_default_wakeup+0xa5/0xf0 drivers/tty/tty_port.c:51
       serial8250_tx_chars+0x629/0x830 drivers/tty/serial/8250/8250_port.c:1828
       serial8250_handle_irq+0x519/0x610 drivers/tty/serial/8250/8250_port.c:1924
       serial8250_default_handle_irq+0xb4/0x1a0 drivers/tty/serial/8250/8250_port.c:1941
       serial8250_interrupt+0x9b/0x1c0 drivers/tty/serial/8250/8250_core.c:127
       __handle_irq_event_percpu+0x291/0x9b0 kernel/irq/handle.c:156
       handle_irq_event_percpu kernel/irq/handle.c:196 [inline]
       handle_irq_event+0xa5/0x220 kernel/irq/handle.c:213
       handle_edge_irq+0x243/0xb20 kernel/irq/chip.c:819
       generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
       handle_irq arch/x86/kernel/irq.c:233 [inline]
       __common_interrupt+0xd7/0x1e0 arch/x86/kernel/irq.c:252
       common_interrupt+0xb0/0xd0 arch/x86/kernel/irq.c:242
       asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
       _raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
       spin_unlock_irqrestore include/linux/spinlock.h:418 [inline]
       uart_write+0x62f/0x880 drivers/tty/serial/serial_core.c:592
       process_output_block drivers/tty/n_tty.c:592 [inline]
       n_tty_write+0xd21/0x1210 drivers/tty/n_tty.c:2339
       do_tty_write drivers/tty/tty_io.c:1038 [inline]
       file_tty_write+0x557/0x910 drivers/tty/tty_io.c:1110
       call_write_iter include/linux/fs.h:2172 [inline]
       new_sync_write fs/read_write.c:507 [inline]
       vfs_write+0x712/0xd00 fs/read_write.c:594
       ksys_write+0x14d/0x250 fs/read_write.c:647
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #1 (&port_lock_key){-...}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
       serial8250_console_write+0x170/0xf80 drivers/tty/serial/8250/8250_port.c:3362
       call_console_drivers kernel/printk/printk.c:-1 [inline]
       console_unlock+0xc86/0x1200 kernel/printk/printk.c:2744
       vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
       _printk+0xcc/0x110 kernel/printk/printk.c:2299
       register_console+0x682/0x960 kernel/printk/printk.c:3107
       univ8250_console_init+0x41/0x50 drivers/tty/serial/8250/8250_core.c:690
       console_init+0x177/0x5d0 kernel/printk/printk.c:3207
       start_kernel+0x2f9/0x530 init/main.c:1076
       secondary_startup_64_no_verify+0xb1/0xbb

-> #0 (console_owner){..-.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
       lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
       console_trylock_spinning+0x170/0x350 kernel/printk/printk.c:1896
       vprintk_emit+0xa7/0x150 kernel/printk/printk.c:2273
       _printk+0xcc/0x110 kernel/printk/printk.c:2299
       show_ip+0x22/0x30 arch/x86/kernel/dumpstack.c:148
       show_iret_regs+0xe/0x40 arch/x86/kernel/dumpstack.c:155
       __show_regs+0x28/0x500 arch/x86/kernel/process_64.c:74
       show_regs+0x32/0x60 arch/x86/kernel/dumpstack.c:471
       __warn+0x15e/0x2b0 kernel/panic.c:678
       report_bug+0x1b7/0x2e0 lib/bug.c:199
       handle_bug+0x3a/0x70 arch/x86/kernel/traps.c:239
       exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:259
       asm_exc_invalid_op+0x16/0x20 arch/x86/include/asm/idtentry.h:604
       copy_from_user_nofault+0x160/0x1c0 mm/maccess.c:226
       bpf_probe_read_user_common kernel/trace/bpf_trace.c:157 [inline]
       ____bpf_probe_read_compat kernel/trace/bpf_trace.c:281 [inline]
       bpf_probe_read_compat+0xdd/0x170 kernel/trace/bpf_trace.c:277
       bpf_prog_8fc34fd13f997abc+0x3d/0x7a4
       bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline]
       __bpf_prog_run include/linux/filter.h:628 [inline]
       bpf_prog_run include/linux/filter.h:635 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline]
       bpf_trace_run3+0x17e/0x320 kernel/trace/bpf_trace.c:1916
       trace_timer_start include/trace/events/timer.h:52 [inline]
       enqueue_timer+0x394/0x520 kernel/time/timer.c:586
       internal_add_timer kernel/time/timer.c:611 [inline]
       __mod_timer+0x8e1/0xd20 kernel/time/timer.c:1062
       mrp_join_timer_arm net/802/mrp.c:596 [inline]
       mrp_join_timer+0x142/0x180 net/802/mrp.c:611
       call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
       expire_timers kernel/time/timer.c:1496 [inline]
       __run_timers+0x525/0x7c0 kernel/time/timer.c:1767
       run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
       handle_softirqs+0x328/0x820 kernel/softirq.c:576
       __do_softirq kernel/softirq.c:610 [inline]
       invoke_softirq kernel/softirq.c:450 [inline]
       __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
       irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
       instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
       sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
       asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
       rep_nop arch/x86/include/asm/vdso/processor.h:13 [inline]
       cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline]
       mutex_spin_on_owner+0x283/0x380 kernel/locking/mutex.c:375
       mutex_optimistic_spin+0x38/0x300 kernel/locking/mutex.c:469
       __mutex_lock_common+0x210/0x2390 kernel/locking/mutex.c:599
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       linkwatch_event+0xa/0x50 net/core/link_watch.c:251
       process_one_work+0x863/0x1000 kernel/workqueue.c:2310
       worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
       kthread+0x436/0x520 kernel/kthread.c:334
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

other info that might help us debug this:

Chain exists of:
  console_owner --> &rq->__lock --> &base->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&base->lock);
                               lock(&rq->__lock);
                               lock(&base->lock);
  lock(console_owner);

 *** DEADLOCK ***

8 locks held by kworker/u4:5/4262:
 #0: ffff888016879138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc900033dfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: ffffffff8d238308 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251
 #3: ffffffff8c11c660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
 #4: ffffc90000dd0be0 ((&app->join_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:45 [inline]
 #4: ffffc90000dd0be0 ((&app->join_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbb/0x530 kernel/time/timer.c:1441
 #5: ffff8880608098c8 (&app->lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:363 [inline]
 #5: ffff8880608098c8 (&app->lock){+.-.}-{2:2}, at: mrp_join_timer+0xd2/0x180 net/802/mrp.c:609
 #6: ffff8880b91280d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:946
 #7: ffffffff8c11c660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311

stack backtrace:
CPU: 1 PID: 4262 Comm: kworker/u4:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events_unbound linkwatch_event
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 console_trylock_spinning+0x170/0x350 kernel/printk/printk.c:1896
 vprintk_emit+0xa7/0x150 kernel/printk/printk.c:2273
 _printk+0xcc/0x110 kernel/printk/printk.c:2299
 show_ip+0x22/0x30 arch/x86/kernel/dumpstack.c:148
 show_iret_regs+0xe/0x40 arch/x86/kernel/dumpstack.c:155
 __show_regs+0x28/0x500 arch/x86/kernel/process_64.c:74
 show_regs+0x32/0x60 arch/x86/kernel/dumpstack.c:471
 __warn+0x15e/0x2b0 kernel/panic.c:678
 report_bug+0x1b7/0x2e0 lib/bug.c:199
 handle_bug+0x3a/0x70 arch/x86/kernel/traps.c:239
 exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:259
 asm_exc_invalid_op+0x16/0x20 arch/x86/include/asm/idtentry.h:604
RIP: 0010:copy_from_user_nofault+0x160/0x1c0 mm/maccess.c:226
Code: 24 45 31 f6 31 ff 89 de e8 6d f7 d8 ff 85 db 48 c7 c0 f2 ff ff ff 49 0f 44 c6 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 f0 f3 d8 ff <0f> 0b e9 1c ff ff ff 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c ea fe
RSP: 0018:ffffc90000dd0930 EFLAGS: 00010046
RAX: ffffffff819ed660 RBX: 0000000000000000 RCX: ffff88805fd75940
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed100bfaeb29
R10: ffffed100bfaeb29 R11: 1ffff1100bfaeb28 R12: ffff88805fd770c8
R13: 00007ffffffff000 R14: ffffc90000dd0968 R15: 0000000020000000
 bpf_probe_read_user_common kernel/trace/bpf_trace.c:157 [inline]
 ____bpf_probe_read_compat kernel/trace/bpf_trace.c:281 [inline]
 bpf_probe_read_compat+0xdd/0x170 kernel/trace/bpf_trace.c:277
 bpf_prog_8fc34fd13f997abc+0x3d/0x7a4
 bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline]
 bpf_trace_run3+0x17e/0x320 kernel/trace/bpf_trace.c:1916
 trace_timer_start include/trace/events/timer.h:52 [inline]
 enqueue_timer+0x394/0x520 kernel/time/timer.c:586
 internal_add_timer kernel/time/timer.c:611 [inline]
 __mod_timer+0x8e1/0xd20 kernel/time/timer.c:1062
 mrp_join_timer_arm net/802/mrp.c:596 [inline]
 mrp_join_timer+0x142/0x180 net/802/mrp.c:611
 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:instrument_atomic_read include/linux/instrumented.h:71 [inline]
RIP: 0010:atomic_long_read include/linux/atomic/atomic-instrumented.h:1183 [inline]
RIP: 0010:__mutex_owner kernel/locking/mutex.c:78 [inline]
RIP: 0010:mutex_spin_on_owner+0x283/0x380 kernel/locking/mutex.c:352
Code: ef be 08 00 00 00 e8 3c f8 60 00 42 80 3c 3b 00 74 08 4c 89 ef e8 9d f6 60 00 49 f7 45 00 01 00 00 00 0f 85 8b 00 00 00 f3 90 <4c> 89 ef be 08 00 00 00 e8 10 f8 60 00 42 80 3c 3b 00 0f 84 84 fe
RSP: 0018:ffffc900033df9b0 EFLAGS: 00000246
RAX: ffff8880b9000000 RBX: 1ffffffff1a47054 RCX: ffffffff815b3ab8
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000
RBP: ffffffff8d2382f0 R08: dffffc0000000000 R09: ffffed100bfaeb29
R10: ffffed100bfaeb29 R11: 1ffff1100bfaeb28 R12: ffff888079993b80
R13: ffffffff8d2382a0 R14: ffffffff8d2382f0 R15: dffffc0000000000
 mutex_optimistic_spin+0x38/0x300 kernel/locking/mutex.c:469
 __mutex_lock_common+0x210/0x2390 kernel/locking/mutex.c:599
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 linkwatch_event+0xa/0x50 net/core/link_watch.c:251
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Code: 24 45 31 f6 31 ff 89 de e8 6d f7 d8 ff 85 db 48 c7 c0 f2 ff ff ff 49 0f 44 c6 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 f0 f3 d8 ff <0f> 0b e9 1c ff ff ff 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c ea fe
RSP: 0018:ffffc90000dd0930 EFLAGS: 00010046

RAX: ffffffff819ed660 RBX: 0000000000000000 RCX: ffff88805fd75940
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed100bfaeb29
R10: ffffed100bfaeb29 R11: 1ffff1100bfaeb28 R12: ffff88805fd770c8
R13: 00007ffffffff000 R14: ffffc90000dd0968 R15: 0000000020000000
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c426452 CR3: 0000000029e9f000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 bpf_probe_read_user_common kernel/trace/bpf_trace.c:157 [inline]
 ____bpf_probe_read_compat kernel/trace/bpf_trace.c:281 [inline]
 bpf_probe_read_compat+0xdd/0x170 kernel/trace/bpf_trace.c:277
 bpf_prog_8fc34fd13f997abc+0x3d/0x7a4
 bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline]
 bpf_trace_run3+0x17e/0x320 kernel/trace/bpf_trace.c:1916
 trace_timer_start include/trace/events/timer.h:52 [inline]
 enqueue_timer+0x394/0x520 kernel/time/timer.c:586
 internal_add_timer kernel/time/timer.c:611 [inline]
 __mod_timer+0x8e1/0xd20 kernel/time/timer.c:1062
 mrp_join_timer_arm net/802/mrp.c:596 [inline]
 mrp_join_timer+0x142/0x180 net/802/mrp.c:611
 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:instrument_atomic_read include/linux/instrumented.h:71 [inline]
RIP: 0010:atomic_long_read include/linux/atomic/atomic-instrumented.h:1183 [inline]
RIP: 0010:__mutex_owner kernel/locking/mutex.c:78 [inline]
RIP: 0010:mutex_spin_on_owner+0x283/0x380 kernel/locking/mutex.c:352
Code: ef be 08 00 00 00 e8 3c f8 60 00 42 80 3c 3b 00 74 08 4c 89 ef e8 9d f6 60 00 49 f7 45 00 01 00 00 00 0f 85 8b 00 00 00 f3 90 <4c> 89 ef be 08 00 00 00 e8 10 f8 60 00 42 80 3c 3b 00 0f 84 84 fe
RSP: 0018:ffffc900033df9b0 EFLAGS: 00000246

RAX: ffff8880b9000000 RBX: 1ffffffff1a47054 RCX: ffffffff815b3ab8
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000
RBP: ffffffff8d2382f0 R08: dffffc0000000000 R09: ffffed100bfaeb29
R10: ffffed100bfaeb29 R11: 1ffff1100bfaeb28 R12: ffff888079993b80
R13: ffffffff8d2382a0 R14: ffffffff8d2382f0 R15: dffffc0000000000
 mutex_optimistic_spin+0x38/0x300 kernel/locking/mutex.c:469
 __mutex_lock_common+0x210/0x2390 kernel/locking/mutex.c:599
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 linkwatch_event+0xa/0x50 net/core/link_watch.c:251
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
----------------
Code disassembly (best guess):
   0:	ef                   	out    %eax,(%dx)
   1:	be 08 00 00 00       	mov    $0x8,%esi
   6:	e8 3c f8 60 00       	call   0x60f847
   b:	42 80 3c 3b 00       	cmpb   $0x0,(%rbx,%r15,1)
  10:	74 08                	je     0x1a
  12:	4c 89 ef             	mov    %r13,%rdi
  15:	e8 9d f6 60 00       	call   0x60f6b7
  1a:	49 f7 45 00 01 00 00 	testq  $0x1,0x0(%r13)
  21:	00
  22:	0f 85 8b 00 00 00    	jne    0xb3
  28:	f3 90                	pause
* 2a:	4c 89 ef             	mov    %r13,%rdi <-- trapping instruction
  2d:	be 08 00 00 00       	mov    $0x8,%esi
  32:	e8 10 f8 60 00       	call   0x60f847
  37:	42 80 3c 3b 00       	cmpb   $0x0,(%rbx,%r15,1)
  3c:	0f                   	.byte 0xf
  3d:	84                   	.byte 0x84
  3e:	84 fe                	test   %bh,%dh

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/03 00:08 linux-5.15.y 29e53a5b1c4f 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in enqueue_task
* Struck through repros no longer work on HEAD.