syzbot


possible deadlock in console_flush_all

Status: upstream: reported C repro on 2025/07/27 16:13
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+2ae00f30639ac005a3f2@syzkaller.appspotmail.com
First crash: 29d, last: 12h46m
Bug presence (1)
Date Name Commit Repro Result
2025/08/01 upstream (ToT) f2d282e1dfb3 C [report] possible deadlock in console_flush_all
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in console_flush_all (4) cgroups 4 C error 226 30m 18d 0/29 upstream: reported C repro on 2025/08/08 11:25
upstream possible deadlock in console_flush_all mm 4 1 709d 705d 0/29 closed as invalid on 2023/09/22 10:29
upstream possible deadlock in console_flush_all (3) bcachefs 4 C error 52145 19d 408d 29/29 fixed on 2025/08/06 17:37
upstream possible deadlock in console_flush_all (2) bpf trace 4 C error 52996 413d 688d 26/29 fixed on 2024/07/09 19:14

Sample crash report:
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 1
======================================================
WARNING: possible circular locking dependency detected
6.6.102-syzkaller #0 Not tainted
------------------------------------------------------
syz.3.600/6608 is trying to acquire lock:
ffffffff8cd23e20 (console_owner){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:339 [inline]
ffffffff8cd23e20 (console_owner){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:232 [inline]
ffffffff8cd23e20 (console_owner){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:292 [inline]
ffffffff8cd23e20 (console_owner){....}-{0:0}, at: console_flush_all+0x10f/0xd00 kernel/printk/printk.c:2992

but task is already holding lock:
ffff8880b8e3c458 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&rq->__lock){-.-.}-{2:2}:
       _raw_spin_lock_nested+0x32/0x50 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558
       raw_spin_rq_lock kernel/sched/sched.h:1372 [inline]
       rq_lock kernel/sched/sched.h:1681 [inline]
       task_fork_fair+0x62/0x1f0 kernel/sched/fair.c:12662
       sched_cgroup_fork+0x333/0x3c0 kernel/sched/core.c:4816
       copy_process+0x21e4/0x3d70 kernel/fork.c:2614
       kernel_clone+0x21b/0x840 kernel/fork.c:2914
       user_mode_thread+0xde/0x130 kernel/fork.c:2992
       rest_init+0x27/0x300 init/main.c:697
       arch_call_rest_init+0xe/0x10 init/main.c:829
       start_kernel+0x459/0x4e0 init/main.c:1074
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
       copy_bootdata+0x0/0xe0 arch/x86/kernel/head64.c:536
       secondary_startup_64_no_verify+0x179/0x17b

-> #3 (&p->pi_lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
       class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:522 [inline]
       try_to_wake_up+0x60/0x1140 kernel/sched/core.c:4232
       __wake_up_common+0x2a4/0x4e0 kernel/sched/wait.c:107
       __wake_up_common_lock kernel/sched/wait.c:138 [inline]
       __wake_up+0x112/0x190 kernel/sched/wait.c:160
       tty_port_default_wakeup+0xa2/0xf0 drivers/tty/tty_port.c:69
       serial8250_tx_chars+0x6bd/0x8a0 drivers/tty/serial/8250/8250_port.c:1837
       serial8250_handle_irq+0x534/0x6e0 drivers/tty/serial/8250/8250_port.c:1944
       serial8250_default_handle_irq+0xb8/0x1a0 drivers/tty/serial/8250/8250_port.c:1964
       serial8250_interrupt+0x9f/0x1c0 drivers/tty/serial/8250/8250_core.c:127
       __handle_irq_event_percpu+0x276/0x930 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:210
       handle_edge_irq+0x247/0xb30 kernel/irq/chip.c:831
       generic_handle_irq_desc include/linux/irqdesc.h:161 [inline]
       handle_irq arch/x86/kernel/irq.c:240 [inline]
       __common_interrupt+0x13b/0x230 arch/x86/kernel/irq.c:259
       common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:249
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:678
       native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
       pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:147
       arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
       default_idle+0x13/0x20 arch/x86/kernel/process.c:753
       default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
       cpuidle_idle_call kernel/sched/idle.c:170 [inline]
       do_idle+0x1eb/0x510 kernel/sched/idle.c:282
       cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380
       rest_init+0x2e2/0x300 init/main.c:732
       arch_call_rest_init+0xe/0x10 init/main.c:829
       start_kernel+0x459/0x4e0 init/main.c:1074
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
       copy_bootdata+0x0/0xe0 arch/x86/kernel/head64.c:536
       secondary_startup_64_no_verify+0x179/0x17b

-> #2 (&tty->write_wait){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
       __wake_up_common_lock kernel/sched/wait.c:137 [inline]
       __wake_up+0xf8/0x190 kernel/sched/wait.c:160
       tty_port_default_wakeup+0xa2/0xf0 drivers/tty/tty_port.c:69
       serial8250_tx_chars+0x6bd/0x8a0 drivers/tty/serial/8250/8250_port.c:1837
       serial8250_handle_irq+0x534/0x6e0 drivers/tty/serial/8250/8250_port.c:1944
       serial8250_default_handle_irq+0xb8/0x1a0 drivers/tty/serial/8250/8250_port.c:1964
       serial8250_interrupt+0x9f/0x1c0 drivers/tty/serial/8250/8250_core.c:127
       __handle_irq_event_percpu+0x276/0x930 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:210
       handle_edge_irq+0x247/0xb30 kernel/irq/chip.c:831
       generic_handle_irq_desc include/linux/irqdesc.h:161 [inline]
       handle_irq arch/x86/kernel/irq.c:240 [inline]
       __common_interrupt+0x13b/0x230 arch/x86/kernel/irq.c:259
       common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:249
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:678
       native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
       pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:147
       arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
       default_idle+0x13/0x20 arch/x86/kernel/process.c:753
       default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
       cpuidle_idle_call kernel/sched/idle.c:170 [inline]
       do_idle+0x1eb/0x510 kernel/sched/idle.c:282
       cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380
       rest_init+0x2e2/0x300 init/main.c:732
       arch_call_rest_init+0xe/0x10 init/main.c:829
       start_kernel+0x459/0x4e0 init/main.c:1074
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
       copy_bootdata+0x0/0xe0 arch/x86/kernel/head64.c:536
       secondary_startup_64_no_verify+0x179/0x17b

-> #1 (&port_lock_key){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
       serial8250_console_write+0x16d/0x17a0 drivers/tty/serial/8250/8250_port.c:3434
       console_emit_next_record kernel/printk/printk.c:2944 [inline]
       console_flush_all+0x6cd/0xd00 kernel/printk/printk.c:3000
       console_unlock+0xae/0x340 kernel/printk/printk.c:3069
       vprintk_emit+0x477/0x600 kernel/printk/printk.c:2341
       _printk+0xd0/0x110 kernel/printk/printk.c:2366
       register_console+0x91b/0xe60 kernel/printk/printk.c:3583
       univ8250_console_init+0x45/0x50 drivers/tty/serial/8250/8250_core.c:717
       console_init+0x17b/0x5e0 kernel/printk/printk.c:3726
       start_kernel+0x2c0/0x4e0 init/main.c:1010
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
       copy_bootdata+0x0/0xe0 arch/x86/kernel/head64.c:536
       secondary_startup_64_no_verify+0x179/0x17b

-> #0 (console_owner){....}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137
       lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
       console_lock_spinning_enable kernel/printk/printk.c:1871 [inline]
       console_emit_next_record kernel/printk/printk.c:2938 [inline]
       console_flush_all+0x693/0xd00 kernel/printk/printk.c:3000
       console_unlock+0xae/0x340 kernel/printk/printk.c:3069
       vprintk_emit+0x477/0x600 kernel/printk/printk.c:2341
       _printk+0xd0/0x110 kernel/printk/printk.c:2366
       fail_dump lib/fault-inject.c:45 [inline]
       should_fail_ex+0x37e/0x4d0 lib/fault-inject.c:153
       strncpy_from_user+0x36/0x2e0 lib/strncpy_from_user.c:118
       strncpy_from_user_nofault+0x71/0x140 mm/maccess.c:186
       bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:212 [inline]
       ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:221 [inline]
       bpf_probe_read_user_str+0x2a/0x70 kernel/trace/bpf_trace.c:218
       bpf_prog_bc7c5c6b9645592f+0x3d/0x3f
       bpf_dispatcher_nop_func include/linux/bpf.h:1213 [inline]
       __bpf_prog_run include/linux/filter.h:612 [inline]
       bpf_prog_run include/linux/filter.h:619 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline]
       bpf_trace_run4+0x1f9/0x420 kernel/trace/bpf_trace.c:2363
       __bpf_trace_sched_switch+0x17b/0x1e0 include/trace/events/sched.h:222
       __traceiter_sched_switch+0x93/0xc0 include/trace/events/sched.h:222
       trace_sched_switch include/trace/events/sched.h:222 [inline]
       __schedule+0x2197/0x44d0 kernel/sched/core.c:6696
       preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009
       irqentry_exit+0x67/0x70 kernel/entry/common.c:438
       asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
       lock_acquire+0x1f2/0x410 kernel/locking/lockdep.c:5758
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1633 [inline]
       sb_start_write include/linux/fs.h:1708 [inline]
       file_start_write+0xc4/0x250 include/linux/fs.h:2711
       vfs_write+0x20e/0x940 fs/read_write.c:580
       ksys_write+0x147/0x250 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

Chain exists of:
  console_owner --> &p->pi_lock --> &rq->__lock

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

5 locks held by syz.3.600/6608:
 #0: ffff888078dc8418 (sb_writers#3){.+.+}-{0:0}, at: vfs_write+0x20e/0x940 fs/read_write.c:580
 #1: ffff8880b8e3c458 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558
 #2: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #2: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #2: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline]
 #2: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0xfd/0x420 kernel/trace/bpf_trace.c:2363
 #3: ffffffff8cd23f00 (console_lock){+.+.}-{0:0}, at: _printk+0xd0/0x110 kernel/printk/printk.c:2366
 #4: ffffffff8cc0b710 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:339 [inline]
 #4: ffffffff8cc0b710 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:232 [inline]
 #4: ffffffff8cc0b710 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:292 [inline]
 #4: ffffffff8cc0b710 (console_srcu){....}-{0:0}, at: console_flush_all+0x10f/0xd00 kernel/printk/printk.c:2992

stack backtrace:
CPU: 0 PID: 6608 Comm: syz.3.600 Not tainted 6.6.102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 check_noncircular+0x2bd/0x3c0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 console_lock_spinning_enable kernel/printk/printk.c:1871 [inline]
 console_emit_next_record kernel/printk/printk.c:2938 [inline]
 console_flush_all+0x693/0xd00 kernel/printk/printk.c:3000
 console_unlock+0xae/0x340 kernel/printk/printk.c:3069
 vprintk_emit+0x477/0x600 kernel/printk/printk.c:2341
 _printk+0xd0/0x110 kernel/printk/printk.c:2366
 fail_dump lib/fault-inject.c:45 [inline]
 should_fail_ex+0x37e/0x4d0 lib/fault-inject.c:153
 strncpy_from_user+0x36/0x2e0 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x71/0x140 mm/maccess.c:186
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:212 [inline]
 ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:221 [inline]
 bpf_probe_read_user_str+0x2a/0x70 kernel/trace/bpf_trace.c:218
 bpf_prog_bc7c5c6b9645592f+0x3d/0x3f
 bpf_dispatcher_nop_func include/linux/bpf.h:1213 [inline]
 __bpf_prog_run include/linux/filter.h:612 [inline]
 bpf_prog_run include/linux/filter.h:619 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline]
 bpf_trace_run4+0x1f9/0x420 kernel/trace/bpf_trace.c:2363
 __bpf_trace_sched_switch+0x17b/0x1e0 include/trace/events/sched.h:222
 __traceiter_sched_switch+0x93/0xc0 include/trace/events/sched.h:222
 trace_sched_switch include/trace/events/sched.h:222 [inline]
 __schedule+0x2197/0x44d0 kernel/sched/core.c:6696
 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009
 irqentry_exit+0x67/0x70 kernel/entry/common.c:438
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:lock_acquire+0x1f2/0x410 kernel/locking/lockdep.c:5758
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00
RSP: 0018:ffffc9000c617ba0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: b3550696ce028a00
RDX: 0000000000000000 RSI: ffffffff8aaacb40 RDI: ffffffff8afc66c0
RBP: ffffc9000c617cc0 R08: dffffc0000000000 R09: 1ffffffff21b46b3
R10: dffffc0000000000 R11: fffffbfff21b46b4 R12: 1ffff920018c2f80
R13: ffff888078dc8418 R14: 0000000000000246 R15: dffffc0000000000
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1633 [inline]
 sb_start_write include/linux/fs.h:1708 [inline]
 file_start_write+0xc4/0x250 include/linux/fs.h:2711
 vfs_write+0x20e/0x940 fs/read_write.c:580
 ksys_write+0x147/0x250 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fbb7598d69f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007ffe8d4f9ee0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbb7598d69f
RDX: 0000000000000001 RSI: 00007ffe8d4f9f50 RDI: 0000000000000005
RBP: 00007ffe8d4f9f40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 00007fbb75bb5fa0 R14: 00007fbb75bb5fa0 R15: 0000000000000003
 </TASK>
CPU: 0 PID: 6608 Comm: syz.3.600 Not tainted 6.6.102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail_ex+0x39d/0x4d0 lib/fault-inject.c:153
 strncpy_from_user+0x36/0x2e0 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x71/0x140 mm/maccess.c:186
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:212 [inline]
 ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:221 [inline]
 bpf_probe_read_user_str+0x2a/0x70 kernel/trace/bpf_trace.c:218
 bpf_prog_bc7c5c6b9645592f+0x3d/0x3f
 bpf_dispatcher_nop_func include/linux/bpf.h:1213 [inline]
 __bpf_prog_run include/linux/filter.h:612 [inline]
 bpf_prog_run include/linux/filter.h:619 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline]
 bpf_trace_run4+0x1f9/0x420 kernel/trace/bpf_trace.c:2363
 __bpf_trace_sched_switch+0x17b/0x1e0 include/trace/events/sched.h:222
 __traceiter_sched_switch+0x93/0xc0 include/trace/events/sched.h:222
 trace_sched_switch include/trace/events/sched.h:222 [inline]
 __schedule+0x2197/0x44d0 kernel/sched/core.c:6696
 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009
 irqentry_exit+0x67/0x70 kernel/entry/common.c:438
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:lock_acquire+0x1f2/0x410 kernel/locking/lockdep.c:5758
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00
RSP: 0018:ffffc9000c617ba0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: b3550696ce028a00
RDX: 0000000000000000 RSI: ffffffff8aaacb40 RDI: ffffffff8afc66c0
RBP: ffffc9000c617cc0 R08: dffffc0000000000 R09: 1ffffffff21b46b3
R10: dffffc0000000000 R11: fffffbfff21b46b4 R12: 1ffff920018c2f80
R13: ffff888078dc8418 R14: 0000000000000246 R15: dffffc0000000000
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1633 [inline]
 sb_start_write include/linux/fs.h:1708 [inline]
 file_start_write+0xc4/0x250 include/linux/fs.h:2711
 vfs_write+0x20e/0x940 fs/read_write.c:580
 ksys_write+0x147/0x250 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fbb7598d69f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007ffe8d4f9ee0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbb7598d69f
RDX: 0000000000000001 RSI: 00007ffe8d4f9f50 RDI: 0000000000000005
RBP: 00007ffe8d4f9f40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 00007fbb75bb5fa0 R14: 00007fbb75bb5fa0 R15: 0000000000000003
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 9c 8f 84 24 80 00 	add    %bl,0x802484(%rdi,%rcx,4)
   7:	00 00                	add    %al,(%rax)
   9:	f6 84 24 81 00 00 00 	testb  $0x2,0x81(%rsp)
  10:	02
  11:	0f 85 f5 00 00 00    	jne    0x10c
  17:	41 f7 c6 00 02 00 00 	test   $0x200,%r14d
  1e:	74 01                	je     0x21
  20:	fb                   	sti
  21:	48 c7 44 24 60 0e 36 	movq   $0x45e0360e,0x60(%rsp)
  28:	e0 45
* 2a:	4b c7 04 3c 00 00 00 	movq   $0x0,(%r12,%r15,1) <-- trapping instruction
  31:	00
  32:	66 43 c7 44 3c 09 00 	movw   $0x0,0x9(%r12,%r15,1)
  39:	00
  3a:	43 c6 44 3c 0b 00    	movb   $0x0,0xb(%r12,%r15,1)

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/22 11:00 linux-6.6.y bb9c90ab9c5a bf27483f .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in console_flush_all
2025/07/28 13:04 linux-6.6.y dbcb8d8e4163 fb8f743d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in console_flush_all
2025/08/26 00:37 linux-6.6.y bb9c90ab9c5a bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in console_flush_all
2025/08/24 02:28 linux-6.6.y bb9c90ab9c5a bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in console_flush_all
2025/08/18 16:56 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in console_flush_all
2025/08/18 14:42 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in console_flush_all
2025/08/18 14:42 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in console_flush_all
2025/08/13 09:29 linux-6.6.y 3a8ababb8b6a 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in console_flush_all
2025/08/09 02:26 linux-6.6.y 3a8ababb8b6a 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in console_flush_all
2025/08/05 08:02 linux-6.6.y 3a8ababb8b6a f5bcc8dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in console_flush_all
2025/08/04 14:18 linux-6.6.y 3a8ababb8b6a 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in console_flush_all
2025/07/28 11:36 linux-6.6.y dbcb8d8e4163 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in console_flush_all
2025/07/27 16:12 linux-6.6.y dbcb8d8e4163 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf possible deadlock in console_flush_all
* Struck through repros no longer work on HEAD.