Hello, syzbot found the following issue on: HEAD commit: 4a5df3796467 Merge tag 'mm-hotfixes-stable-2024-11-16-15-3.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=155c32c0580000 kernel config: https://syzkaller.appspot.com/x/.config?x=9b216897c3460507 dashboard link: https://syzkaller.appspot.com/bug?extid=e5ebce0ffa64d4f9e0cb compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/9d63a0b7130f/disk-4a5df379.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/b5fa43c492f5/vmlinux-4a5df379.xz kernel image: https://storage.googleapis.com/syzbot-assets/553263ff3107/bzImage-4a5df379.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+e5ebce0ffa64d4f9e0cb@xxxxxxxxxxxxxxxxxxxxxxxxx kauditd_printk_skb: 9 callbacks suppressed audit: type=1800 audit(1731828236.598:84): pid=8906 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="syz.1.810" name="bus" dev="overlay" ino=1020 res=0 errno=0 audit: type=1800 audit(1731828236.698:85): pid=8913 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="syz.1.810" name="bus" dev="overlay" ino=1020 res=0 errno=0 ====================================================== WARNING: possible circular locking dependency detected 6.12.0-rc7-syzkaller-00212-g4a5df3796467 #0 Not tainted ------------------------------------------------------ kauditd/29 is trying to acquire lock: ffff88805b364618 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline] ffff88805b364618 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xbe/0x14b0 kernel/sched/core.c:4165 but task is already holding lock: ffffffff8e813418 ((console_sem).lock){-.-.}-{2:2}, at: up+0x1d/0x90 kernel/locking/semaphore.c:187 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 ((console_sem).lock){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 down_trylock+0x20/0xa0 kernel/locking/semaphore.c:139 __down_trylock_console_sem+0x109/0x250 kernel/printk/printk.c:326 console_trylock kernel/printk/printk.c:2827 [inline] console_trylock_spinning kernel/printk/printk.c:1990 [inline] vprintk_emit+0x3d7/0xa10 kernel/printk/printk.c:2406 _printk+0xd5/0x120 kernel/printk/printk.c:2432 fail_dump lib/fault-inject.c:46 [inline] should_fail_ex+0x391/0x4e0 lib/fault-inject.c:154 strncpy_from_user+0x36/0x260 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:215 [inline] ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:310 [inline] bpf_probe_read_compat_str+0xe9/0x180 kernel/trace/bpf_trace.c:306 0xffffffffa0000859 bpf_dispatcher_nop_func include/linux/bpf.h:1265 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2316 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2357 trace_tlb_flush+0x118/0x140 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x77a/0xa70 context_switch kernel/sched/core.c:5312 [inline] __schedule+0x10c7/0x4bd0 kernel/sched/core.c:6693 preempt_schedule_notrace+0x100/0x140 kernel/sched/core.c:6965 preempt_schedule_notrace_thunk+0x1a/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x7e/0xb0 kernel/rcu/tree.c:738 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0xe3/0x550 kernel/locking/lockdep.c:5796 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] atomic_notifier_call_chain+0x43/0x180 kernel/notifier.c:230 do_con_write+0xab1/0x4c30 drivers/tty/vt/vt.c:3086 con_put_char+0x95/0xf0 drivers/tty/vt/vt.c:3442 tty_put_char+0xe3/0x190 drivers/tty/tty_io.c:3167 do_output_char+0x6b1/0x970 drivers/tty/n_tty.c:469 process_output drivers/tty/n_tty.c:494 [inline] n_tty_write+0xe06/0x1230 drivers/tty/n_tty.c:2400 iterate_tty_write drivers/tty/tty_io.c:1015 [inline] file_tty_write+0x546/0x9b0 drivers/tty/tty_io.c:1090 new_sync_write fs/read_write.c:590 [inline] vfs_write+0xaeb/0xd30 fs/read_write.c:683 ksys_write+0x183/0x2b0 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598 raw_spin_rq_lock kernel/sched/sched.h:1506 [inline] task_rq_lock+0xc6/0x360 kernel/sched/core.c:700 cgroup_move_task+0x9b/0x5a0 kernel/sched/psi.c:1161 css_set_move_task+0x72e/0x950 kernel/cgroup/cgroup.c:898 cgroup_post_fork+0x256/0x880 kernel/cgroup/cgroup.c:6692 copy_process+0x39e9/0x3d50 kernel/fork.c:2600 kernel_clone+0x223/0x880 kernel/fork.c:2786 user_mode_thread+0x132/0x1a0 kernel/fork.c:2864 rest_init+0x23/0x300 init/main.c:712 start_kernel+0x47f/0x500 init/main.c:1105 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x147 -> #0 (&p->pi_lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline] try_to_wake_up+0xbe/0x14b0 kernel/sched/core.c:4165 up+0x72/0x90 kernel/locking/semaphore.c:191 __up_console_sem kernel/printk/printk.c:343 [inline] __console_unlock+0x123/0x1f0 kernel/printk/printk.c:2844 __console_flush_and_unlock kernel/printk/printk.c:3241 [inline] console_unlock+0x18f/0x3b0 kernel/printk/printk.c:3279 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2407 _printk+0xd5/0x120 kernel/printk/printk.c:2432 kauditd_printk_skb kernel/audit.c:546 [inline] kauditd_hold_skb+0x1be/0x210 kernel/audit.c:581 kauditd_send_queue+0x2b1/0x310 kernel/audit.c:766 kauditd_thread+0x74a/0x9b0 kernel/audit.c:890 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 other info that might help us debug this: Chain exists of: &p->pi_lock --> &rq->__lock --> (console_sem).lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((console_sem).lock); lock(&rq->__lock); lock((console_sem).lock); lock(&p->pi_lock); *** DEADLOCK *** 1 lock held by kauditd/29: #0: ffffffff8e813418 ((console_sem).lock){-.-.}-{2:2}, at: up+0x1d/0x90 kernel/locking/semaphore.c:187 stack backtrace: CPU: 1 UID: 0 PID: 29 Comm: kauditd Not tainted 6.12.0-rc7-syzkaller-00212-g4a5df3796467 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline] try_to_wake_up+0xbe/0x14b0 kernel/sched/core.c:4165 up+0x72/0x90 kernel/locking/semaphore.c:191 __up_console_sem kernel/printk/printk.c:343 [inline] __console_unlock+0x123/0x1f0 kernel/printk/printk.c:2844 __console_flush_and_unlock kernel/printk/printk.c:3241 [inline] console_unlock+0x18f/0x3b0 kernel/printk/printk.c:3279 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2407 _printk+0xd5/0x120 kernel/printk/printk.c:2432 kauditd_printk_skb kernel/audit.c:546 [inline] kauditd_hold_skb+0x1be/0x210 kernel/audit.c:581 kauditd_send_queue+0x2b1/0x310 kernel/audit.c:766 kauditd_thread+0x74a/0x9b0 kernel/audit.c:890 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
