Kernel panic - not syncing: kernel: panic_on_warn set ...

======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.9.517/6339 is trying to acquire lock:
ffffffff8cb21d40 (console_owner){..-.}-{0:0}, at: console_lock_spinning_enable kernel/printk/printk.c:1818 [inline]
ffffffff8cb21d40 (console_owner){..-.}-{0:0}, at: console_emit_next_record+0x68f/0xb50 kernel/printk/printk.c:2774

but task is already holding lock:
ffff88802ba9a818 (&p->pi_lock){-.-.}-{2:2}, at: task_call_func+0x3f/0x260 kernel/sched/core.c:4293

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&p->pi_lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162
       try_to_wake_up+0x5a/0x10b0 kernel/sched/core.c:4112
       __wake_up_common+0x28e/0x4d0 kernel/sched/wait.c:107
       __wake_up_common_lock kernel/sched/wait.c:138 [inline]
       __wake_up+0x121/0x1a0 kernel/sched/wait.c:160
       tty_port_default_wakeup+0x9e/0xf0 drivers/tty/tty_port.c:71
       serial8250_tx_chars+0x615/0x800 drivers/tty/serial/8250/8250_port.c:1854
       serial8250_handle_irq+0x554/0x720 drivers/tty/serial/8250/8250_port.c:1961
       serial8250_default_handle_irq+0xb4/0x1a0 drivers/tty/serial/8250/8250_port.c:1981
       serial8250_interrupt+0x9b/0x1c0 drivers/tty/serial/8250/8250_core.c:126
       __handle_irq_event_percpu+0x293/0xa50 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x87/0x1e0 kernel/irq/handle.c:210
       handle_edge_irq+0x242/0xb20 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:682
       kasan_quarantine_put+0x84/0x210 arch/x86/include/asm/irqflags.h:-1
       kasan_slab_free include/linux/kasan.h:177 [inline]
       slab_free_hook mm/slub.c:1729 [inline]
       slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755
       slab_free mm/slub.c:3687 [inline]
       kmem_cache_free_bulk+0x364/0x480 mm/slub.c:3805
       mt_free_bulk lib/maple_tree.c:164 [inline]
       mas_destroy+0x251f/0x2d40 lib/maple_tree.c:5864
       mas_store_prealloc+0x32c/0x430 lib/maple_tree.c:5792
       __vma_adjust+0xfd6/0x1d00 mm/mmap.c:805
       vma_adjust include/linux/mm.h:2810 [inline]
       __split_vma+0x3a2/0x4f0 mm/mmap.c:-1
       do_mas_align_munmap+0x7b8/0x12d0 mm/mmap.c:2501
       do_mas_munmap+0x240/0x2b0 mm/mmap.c:2650
       __mmap_region mm/mmap.c:2698 [inline]
       mmap_region+0x7ab/0x1c50 mm/mmap.c:2916
       do_mmap+0x9ce/0x10d0 mm/mmap.c:1436
       vm_mmap_pgoff+0x1c1/0x2d0 mm/util.c:520
       ksys_mmap_pgoff+0x4bf/0x720 mm/mmap.c:1482
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #2 (&tty->write_wait){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162
       __wake_up_common_lock kernel/sched/wait.c:137 [inline]
       __wake_up+0x107/0x1a0 kernel/sched/wait.c:160
       tty_port_default_wakeup+0x9e/0xf0 drivers/tty/tty_port.c:71
       serial8250_tx_chars+0x615/0x800 drivers/tty/serial/8250/8250_port.c:1854
       serial8250_handle_irq+0x554/0x720 drivers/tty/serial/8250/8250_port.c:1961
       serial8250_default_handle_irq+0xb4/0x1a0 drivers/tty/serial/8250/8250_port.c:1981
       serial8250_interrupt+0x9b/0x1c0 drivers/tty/serial/8250/8250_core.c:126
       __handle_irq_event_percpu+0x293/0xa50 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x87/0x1e0 kernel/irq/handle.c:210
       handle_edge_irq+0x242/0xb20 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:682
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
       _raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194
       spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
       uart_write+0x67a/0x900 drivers/tty/serial/serial_core.c:602
       process_output_block drivers/tty/n_tty.c:586 [inline]
       n_tty_write+0xd61/0x11e0 drivers/tty/n_tty.c:2377
       do_tty_write drivers/tty/tty_io.c:1018 [inline]
       file_tty_write+0x4c7/0x840 drivers/tty/tty_io.c:1089
       call_write_iter include/linux/fs.h:2265 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x482/0x9a0 fs/read_write.c:584
       ksys_write+0x14d/0x260 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (&port_lock_key){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162
       serial8250_console_write+0x17d/0x18b0 drivers/tty/serial/8250/8250_port.c:3438
       call_console_driver kernel/printk/printk.c:1977 [inline]
       console_emit_next_record+0x795/0xb50 kernel/printk/printk.c:2777
       console_flush_all kernel/printk/printk.c:-1 [inline]
       console_unlock+0x223/0x630 kernel/printk/printk.c:2906
       vprintk_emit+0x4b3/0x6a0 kernel/printk/printk.c:2303
       _printk+0xda/0x130 kernel/printk/printk.c:2328
       register_console+0x6bd/0x9b0 kernel/printk/printk.c:3269
       univ8250_console_init+0x41/0x43 drivers/tty/serial/8250/8250_core.c:687
       console_init+0x1bc/0x78e kernel/printk/printk.c:3359
       start_kernel+0x306/0x53c init/main.c:1087
       secondary_startup_64_no_verify+0xcf/0xdb

-> #0 (console_owner){..-.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3095 [inline]
       check_prevs_add kernel/locking/lockdep.c:3214 [inline]
       validate_chain kernel/locking/lockdep.c:3830 [inline]
       __lock_acquire+0x2d18/0x7c40 kernel/locking/lockdep.c:5063
       lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676
       console_lock_spinning_enable kernel/printk/printk.c:1818 [inline]
       console_emit_next_record+0x6b0/0xb50 kernel/printk/printk.c:2774
       console_flush_all kernel/printk/printk.c:-1 [inline]
       console_unlock+0x223/0x630 kernel/printk/printk.c:2906
       vprintk_emit+0x4b3/0x6a0 kernel/printk/printk.c:2303
       _printk+0xda/0x130 kernel/printk/printk.c:2328
       panic+0x269/0x710 kernel/panic.c:333
       check_panic_on_warn kernel/panic.c:235 [inline]
       __warn+0x2f8/0x4f0 kernel/panic.c:680
       __report_bug lib/bug.c:199 [inline]
       report_bug+0x2ba/0x4f0 lib/bug.c:219
       handle_bug+0x3a/0x70 arch/x86/kernel/traps.c:324
       exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:345
       asm_exc_invalid_op+0x16/0x20 arch/x86/include/asm/idtentry.h:606
       __set_task_frozen+0x1e9/0x290 kernel/freezer.c:129
       task_call_func+0x19e/0x260 kernel/sched/core.c:4308
       __freeze_task kernel/freezer.c:139 [inline]
       freeze_task+0x213/0x3a0 kernel/freezer.c:158
       try_to_freeze_tasks+0x190/0x600 kernel/power/process.c:54
       freeze_processes+0xc5/0x1e0 kernel/power/process.c:137
       hibernate+0x142/0x520 kernel/power/hibernate.c:752
       state_store+0x22b/0x290 kernel/power/main.c:641
       kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
       call_write_iter include/linux/fs.h:2265 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x482/0x9a0 fs/read_write.c:584
       ksys_pwrite64 fs/read_write.c:699 [inline]
       __do_sys_pwrite64 fs/read_write.c:709 [inline]
       __se_sys_pwrite64 fs/read_write.c:706 [inline]
       __x64_sys_pwrite64+0x194/0x220 fs/read_write.c:706
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

Chain exists of:
  console_owner --> &tty->write_wait --> &p->pi_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&p->pi_lock);
                               lock(&tty->write_wait);
                               lock(&p->pi_lock);
  lock(console_owner);

 *** DEADLOCK ***

8 locks held by syz.9.517/6339:
 #0: ffff888024b04460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
 #1: ffff888078bac088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1d8/0x520 fs/kernfs/file.c:343
 #2: ffff8881401e3a00 (kn->active#65){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff8881401e3a00 (kn->active#65){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x520 fs/kernfs/file.c:344
 #3: ffffffff8c9e2e28 (system_transition_mutex){+.+.}-{3:3}, at: lock_system_sleep+0x45/0x60 kernel/power/main.c:28
 #4: ffffffff8c80a058 (tasklist_lock){.+.+}-{2:2}, at: try_to_freeze_tasks+0xe5/0x600 kernel/power/process.c:52
 #5: ffffffff8cb40658 (freezer_lock){....}-{2:2}, at: freeze_task+0x7c/0x3a0 kernel/freezer.c:157
 #6: ffff88802ba9a818 (&p->pi_lock){-.-.}-{2:2}, at: task_call_func+0x3f/0x260 kernel/sched/core.c:4293
 #7: ffffffff8cb21e20 (console_lock){+.+.}-{0:0}, at: _printk+0xda/0x130 kernel/printk/printk.c:2328

stack backtrace:
CPU: 1 PID: 6339 Comm: syz.9.517 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3095 [inline]
 check_prevs_add kernel/locking/lockdep.c:3214 [inline]
 validate_chain kernel/locking/lockdep.c:3830 [inline]
 __lock_acquire+0x2d18/0x7c40 kernel/locking/lockdep.c:5063
 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676
 console_lock_spinning_enable kernel/printk/printk.c:1818 [inline]
 console_emit_next_record+0x6b0/0xb50 kernel/printk/printk.c:2774
 console_flush_all kernel/printk/printk.c:-1 [inline]
 console_unlock+0x223/0x630 kernel/printk/printk.c:2906
 vprintk_emit+0x4b3/0x6a0 kernel/printk/printk.c:2303
 _printk+0xda/0x130 kernel/printk/printk.c:2328
 panic+0x269/0x710 kernel/panic.c:333
 check_panic_on_warn kernel/panic.c:235 [inline]
 __warn+0x2f8/0x4f0 kernel/panic.c:680
 __report_bug lib/bug.c:199 [inline]
 report_bug+0x2ba/0x4f0 lib/bug.c:219
 handle_bug+0x3a/0x70 arch/x86/kernel/traps.c:324
 exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:345
 asm_exc_invalid_op+0x16/0x20 arch/x86/include/asm/idtentry.h:606
RIP: 0010:__set_task_frozen+0x1e9/0x290 kernel/freezer.c:129
Code: 68 c7 03 00 80 00 00 bd 00 80 00 00 89 e8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 a3 83 11 00 0f 0b e9 2c ff ff ff e8 97 83 11 00 <0f> 0b eb bf 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 38 fe ff ff 48 89
RSP: 0018:ffffc9000d5cfa70 EFLAGS: 00010046
RAX: ffffffff8170aa89 RBX: ffff88802ba99e18 RCX: 0000000000080000
RDX: ffffc900120ff000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52001ab9f30 R12: 0000000000000000
R13: 1ffff110057533c3 R14: ffff88802ba9a8d8 R15: dffffc0000000000
 task_call_func+0x19e/0x260 kernel/sched/core.c:4308
 __freeze_task kernel/freezer.c:139 [inline]
 freeze_task+0x213/0x3a0 kernel/freezer.c:158
 try_to_freeze_tasks+0x190/0x600 kernel/power/process.c:54
 freeze_processes+0xc5/0x1e0 kernel/power/process.c:137
 hibernate+0x142/0x520 kernel/power/hibernate.c:752
 state_store+0x22b/0x290 kernel/power/main.c:641
 kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x482/0x9a0 fs/read_write.c:584
 ksys_pwrite64 fs/read_write.c:699 [inline]
 __do_sys_pwrite64 fs/read_write.c:709 [inline]
 __se_sys_pwrite64 fs/read_write.c:706 [inline]
 __x64_sys_pwrite64+0x194/0x220 fs/read_write.c:706
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7feeaf99e019
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007feeb0910028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007feeafc25fa0 RCX: 00007feeaf99e019
RDX: 0000000000000006 RSI: 0000200000000200 RDI: 0000000000000003
RBP: 00007feeafa3500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007feeafc26038 R14: 00007feeafc25fa0 R15: 00007ffc5ac30bb8
 </TASK>
CPU: 1 PID: 6339 Comm: syz.9.517 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 panic+0x2d3/0x710 kernel/panic.c:339
 check_panic_on_warn kernel/panic.c:235 [inline]
 __warn+0x2f8/0x4f0 kernel/panic.c:680
 __report_bug lib/bug.c:199 [inline]
 report_bug+0x2ba/0x4f0 lib/bug.c:219
 handle_bug+0x3a/0x70 arch/x86/kernel/traps.c:324
 exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:345
 asm_exc_invalid_op+0x16/0x20 arch/x86/include/asm/idtentry.h:606
RIP: 0010:__set_task_frozen+0x1e9/0x290 kernel/freezer.c:129
Code: 68 c7 03 00 80 00 00 bd 00 80 00 00 89 e8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 a3 83 11 00 0f 0b e9 2c ff ff ff e8 97 83 11 00 <0f> 0b eb bf 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 38 fe ff ff 48 89
RSP: 0018:ffffc9000d5cfa70 EFLAGS: 00010046
RAX: ffffffff8170aa89 RBX: ffff88802ba99e18 RCX: 0000000000080000
RDX: ffffc900120ff000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52001ab9f30 R12: 0000000000000000
R13: 1ffff110057533c3 R14: ffff88802ba9a8d8 R15: dffffc0000000000
 task_call_func+0x19e/0x260 kernel/sched/core.c:4308
 __freeze_task kernel/freezer.c:139 [inline]
 freeze_task+0x213/0x3a0 kernel/freezer.c:158
 try_to_freeze_tasks+0x190/0x600 kernel/power/process.c:54
 freeze_processes+0xc5/0x1e0 kernel/power/process.c:137
 hibernate+0x142/0x520 kernel/power/hibernate.c:752
 state_store+0x22b/0x290 kernel/power/main.c:641
 kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x482/0x9a0 fs/read_write.c:584
 ksys_pwrite64 fs/read_write.c:699 [inline]
 __do_sys_pwrite64 fs/read_write.c:709 [inline]
 __se_sys_pwrite64 fs/read_write.c:706 [inline]
 __x64_sys_pwrite64+0x194/0x220 fs/read_write.c:706
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7feeaf99e019
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007feeb0910028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007feeafc25fa0 RCX: 00007feeaf99e019
RDX: 0000000000000006 RSI: 0000200000000200 RDI: 0000000000000003
RBP: 00007feeafa3500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007feeafc26038 R14: 00007feeafc25fa0 R15: 00007ffc5ac30bb8
 </TASK>
Shutting down cpus with NMI
Kernel Offset: disabled
Rebooting in 86400 seconds..