syzbot

FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
======================================================
WARNING: possible circular locking dependency detected
6.1.129-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor258/4497 is trying to acquire lock:
ffffffff8d322840 (console_owner){-...}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:1935 [inline]
ffffffff8d322840 (console_owner){-...}-{0:0}, at: vprintk_emit+0x340/0x740 kernel/printk/printk.c:2302

but task is already holding lock:
ffff8880b8f3a9d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&rq->__lock){-.-.}-{2:2}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
       raw_spin_rq_lock kernel/sched/sched.h:1355 [inline]
       rq_lock kernel/sched/sched.h:1645 [inline]
       task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11886
       sched_cgroup_fork+0x374/0x400 kernel/sched/core.c:4684
       copy_process+0x2482/0x40a0 kernel/fork.c:2383
       kernel_clone+0x222/0x920 kernel/fork.c:2681
       user_mode_thread+0x140/0x1b0 kernel/fork.c:2757
       rest_init+0x23/0x300 init/main.c:698
       start_kernel+0x0/0x53f init/main.c:893
       start_kernel+0x496/0x53f init/main.c:1140
       secondary_startup_64_no_verify+0xcf/0xdb

-> #3 (&p->pi_lock){-.-.}-{2:2}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
       try_to_wake_up+0xad/0x1250 kernel/sched/core.c:4110
       __wake_up_common+0x2a0/0x4e0 kernel/sched/wait.c:107
       __wake_up_common_lock kernel/sched/wait.c:138 [inline]
       __wake_up+0x11a/0x1c0 kernel/sched/wait.c:160
       tty_port_default_wakeup+0xa2/0xf0 drivers/tty/tty_port.c:71
       serial8250_tx_chars+0x60d/0x800 drivers/tty/serial/8250/8250_port.c:1854
       serial8250_handle_irq+0x4ff/0x6a0 drivers/tty/serial/8250/8250_port.c:1961
       serial8250_default_handle_irq+0xc8/0x1e0 drivers/tty/serial/8250/8250_port.c:1981
       serial8250_interrupt+0xa1/0x1e0 drivers/tty/serial/8250/8250_core.c:126
       __handle_irq_event_percpu+0x2a8/0xb20 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x85/0x1e0 kernel/irq/handle.c:210
       handle_edge_irq+0x245/0xbf0 kernel/irq/chip.c:819
       generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
       handle_irq arch/x86/kernel/irq.c:231 [inline]
       __common_interrupt+0xd7/0x1f0 arch/x86/kernel/irq.c:250
       common_interrupt+0xae/0xd0 arch/x86/kernel/irq.c:240
       asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:682
       __kernel_text_address+0x30/0x40 kernel/extable.c:92
       unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323
       arch_stack_walk+0xf3/0x140 arch/x86/kernel/stacktrace.c:26
       stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
       kasan_save_stack mm/kasan/common.c:45 [inline]
       kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
       kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
       ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
       kasan_slab_free include/linux/kasan.h:177 [inline]
       slab_free_hook mm/slub.c:1724 [inline]
       slab_free_freelist_hook mm/slub.c:1750 [inline]
       slab_free mm/slub.c:3661 [inline]
       kmem_cache_free+0x292/0x510 mm/slub.c:3683
       remove_vma mm/mmap.c:143 [inline]
       exit_mmap+0x4cf/0x980 mm/mmap.c:3260
       __mmput+0x115/0x3c0 kernel/fork.c:1200
       exec_mmap+0x4fa/0x5b0 fs/exec.c:1040
       begin_new_exec+0xb65/0x2090 fs/exec.c:1299
       load_elf_binary+0x955/0x2720 fs/binfmt_elf.c:1002
       search_binary_handler fs/exec.c:1764 [inline]
       exec_binprm fs/exec.c:1805 [inline]
       bprm_execve+0x96a/0x18a0 fs/exec.c:1874
       do_execveat_common+0x580/0x720 fs/exec.c:1979
       do_execve fs/exec.c:2053 [inline]
       __do_sys_execve fs/exec.c:2129 [inline]
       __se_sys_execve fs/exec.c:2124 [inline]
       __x64_sys_execve+0x8e/0xa0 fs/exec.c:2124
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #2 (&tty->write_wait){-.-.}-{2:2}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
       __wake_up_common_lock kernel/sched/wait.c:137 [inline]
       __wake_up+0xfd/0x1c0 kernel/sched/wait.c:160
       tty_port_default_wakeup+0xa2/0xf0 drivers/tty/tty_port.c:71
       serial8250_tx_chars+0x60d/0x800 drivers/tty/serial/8250/8250_port.c:1854
       serial8250_handle_irq+0x4ff/0x6a0 drivers/tty/serial/8250/8250_port.c:1961
       serial8250_default_handle_irq+0xc8/0x1e0 drivers/tty/serial/8250/8250_port.c:1981
       serial8250_interrupt+0xa1/0x1e0 drivers/tty/serial/8250/8250_core.c:126
       __handle_irq_event_percpu+0x2a8/0xb20 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x85/0x1e0 kernel/irq/handle.c:210
       handle_edge_irq+0x245/0xbf0 kernel/irq/chip.c:819
       generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
       handle_irq arch/x86/kernel/irq.c:231 [inline]
       __common_interrupt+0xd7/0x1f0 arch/x86/kernel/irq.c:250
       common_interrupt+0xae/0xd0 arch/x86/kernel/irq.c:240
       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+0xd4/0x130 kernel/locking/spinlock.c:194
       spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
       uart_write+0x66d/0x8d0 drivers/tty/serial/serial_core.c:602
       process_output_block drivers/tty/n_tty.c:586 [inline]
       n_tty_write+0xd7f/0x1260 drivers/tty/n_tty.c:2377
       do_tty_write drivers/tty/tty_io.c:1018 [inline]
       file_tty_write+0x504/0x890 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+0x857/0xbc0 fs/read_write.c:584
       ksys_write+0x19c/0x2c0 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (&port_lock_key){-.-.}-{2:2}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
       serial8250_console_write+0x19f/0x1a30 drivers/tty/serial/8250/8250_port.c:3433
       call_console_driver kernel/printk/printk.c:1977 [inline]
       console_emit_next_record+0x86d/0xc30 kernel/printk/printk.c:2777
       console_unlock+0x278/0x7c0 kernel/printk/printk.c:2906
       vprintk_emit+0x523/0x740 kernel/printk/printk.c:2303
       _printk+0xd1/0x111 kernel/printk/printk.c:2328
       register_console+0x6b9/0x9a0 kernel/printk/printk.c:3269
       univ8250_console_init+0x41/0x43 drivers/tty/serial/8250/8250_core.c:687
       console_init+0x1d6/0x7f3 kernel/printk/printk.c:3359
       start_kernel+0x30b/0x53f init/main.c:1076
       secondary_startup_64_no_verify+0xcf/0xdb

-> #0 (console_owner){-...}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       console_trylock_spinning kernel/printk/printk.c:1935 [inline]
       vprintk_emit+0x35d/0x740 kernel/printk/printk.c:2302
       _printk+0xd1/0x111 kernel/printk/printk.c:2328
       fail_dump lib/fault-inject.c:45 [inline]
       should_fail_ex+0x387/0x4d0 lib/fault-inject.c:147
       strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118
       strncpy_from_user_nofault+0x6c/0x130 mm/maccess.c:186
       bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:204 [inline]
       ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:310 [inline]
       bpf_probe_read_compat_str+0xe4/0x180 kernel/trace/bpf_trace.c:306
       bpf_prog_c1796171ffc7efef+0x35/0x37
       bpf_dispatcher_nop_func include/linux/bpf.h:1000 [inline]
       __bpf_prog_run include/linux/filter.h:603 [inline]
       bpf_prog_run include/linux/filter.h:610 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline]
       bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2325
       __traceiter_sched_switch+0x91/0xc0 include/trace/events/sched.h:222
       trace_sched_switch include/trace/events/sched.h:222 [inline]
       __schedule+0x2128/0x4570 kernel/sched/core.c:6557
       preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6872
       irqentry_exit+0x53/0x80 kernel/entry/common.c:439
       asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
       ksys_write+0x1c6/0x2c0 fs/read_write.c:639
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/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 ***

3 locks held by syz-executor258/4497:
 #0: ffff888027b7eae8
 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ba/0x360 fs/file.c:1032
 #1: ffff8880b8f3a9d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
 #2: ffffffff8d32e680 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #2: ffffffff8d32e680 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #2: ffffffff8d32e680 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2283 [inline]
 #2: ffffffff8d32e680 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x16a/0x470 kernel/trace/bpf_trace.c:2325

stack backtrace:
CPU: 1 PID: 4497 Comm: syz-executor258 Not tainted 6.1.129-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 console_trylock_spinning kernel/printk/printk.c:1935 [inline]
 vprintk_emit+0x35d/0x740 kernel/printk/printk.c:2302
 _printk+0xd1/0x111 kernel/printk/printk.c:2328
 fail_dump lib/fault-inject.c:45 [inline]
 should_fail_ex+0x387/0x4d0 lib/fault-inject.c:147
 strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x6c/0x130 mm/maccess.c:186
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:204 [inline]
 ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:310 [inline]
 bpf_probe_read_compat_str+0xe4/0x180 kernel/trace/bpf_trace.c:306
 bpf_prog_c1796171ffc7efef+0x35/0x37
 bpf_dispatcher_nop_func include/linux/bpf.h:1000 [inline]
 __bpf_prog_run include/linux/filter.h:603 [inline]
 bpf_prog_run include/linux/filter.h:610 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline]
 bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2325
 __traceiter_sched_switch+0x91/0xc0 include/trace/events/sched.h:222
 trace_sched_switch include/trace/events/sched.h:222 [inline]
 __schedule+0x2128/0x4570 kernel/sched/core.c:6557
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6872
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:ksys_write+0x1c6/0x2c0 fs/read_write.c:639
Code: 49 89 c4 31 ff 48 89 c6 e8 77 fe 99 ff 4d 85 ed 74 57 4d 85 e4 78 52 e8 88 fa 99 ff 48 8b 44 24 20 80 3c 18 00 4c 8b 6c 24 28 <74> 0a 48 8d 7c 24 60 e8 ae 52 f1 ff 48 8b 5c 24 60 4c 89 f8 48 c1
RSP: 0018:ffffc9000498fe40 EFLAGS: 00000246
RAX: 1ffff92000931fd4 RBX: dffffc0000000000 RCX: ffff888073d29dc0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000498ff20 R08: ffffffff81f09c39 R09: fffffbfff1d413e6
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001
R13: 1ffff92000931fd0 R14: ffff888027b7ea03 R15: ffff888027b7eb10
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fcd1c7b471f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 c9 84 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 1c 85 02 00 48
RSP: 002b:00007fcd1bf47120 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fcd1bf47150 RCX: 00007fcd1c7b471f
RDX: 0000000000000001 RSI: 00007fcd1bf47150 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000000000000 R09: 00007fcd1bf46ee7
R10: 0000000000000000 R11: 0000000000000293 R12: 00007fcd1c83941c
R13: 000000000000006e R14: 00007fff44b74b70 R15: 00007fff44b74c58
 </TASK>
CPU: 1 PID: 4497 Comm: syz-executor258 Not tainted 6.1.129-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail_ex+0x3a6/0x4d0 lib/fault-inject.c:147
 strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x6c/0x130 mm/maccess.c:186
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:204 [inline]
 ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:310 [inline]
 bpf_probe_read_compat_str+0xe4/0x180 kernel/trace/bpf_trace.c:306
 bpf_prog_c1796171ffc7efef+0x35/0x37
 bpf_dispatcher_nop_func include/linux/bpf.h:1000 [inline]
 __bpf_prog_run include/linux/filter.h:603 [inline]
 bpf_prog_run include/linux/filter.h:610 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline]
 bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2325
 __traceiter_sched_switch+0x91/0xc0 include/trace/events/sched.h:222
 trace_sched_switch include/trace/events/sched.h:222 [inline]
 __schedule+0x2128/0x4570 kernel/sched/core.c:6557
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6872
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:ksys_write+0x1c6/0x2c0 fs/read_write.c:639
Code: 49 89 c4 31 ff 48 89 c6 e8 77 fe 99 ff 4d 85 ed 74 57 4d 85 e4 78 52 e8 88 fa 99 ff 48 8b 44 24 20 80 3c 18 00 4c 8b 6c 24 28 <74> 0a 48 8d 7c 24 60 e8 ae 52 f1 ff 48 8b 5c 24 60 4c 89 f8 48 c1
RSP: 0018:ffffc9000498fe40 EFLAGS: 00000246
RAX: 1ffff92000931fd4 RBX: dffffc0000000000 RCX: ffff888073d29dc0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000498ff20 R08: ffffffff81f09c39 R09: fffffbfff1d413e6
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001
R13: 1ffff92000931fd0 R14: ffff888027b7ea03 R15: ffff888027b7eb10
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fcd1c7b471f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 c9 84 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 1c 85 02 00 48
RSP: 002b:00007fcd1bf47120 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fcd1bf47150 RCX: 00007fcd1c7b471f
RDX: 0000000000000001 RSI: 00007fcd1bf47150 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000000000000 R09: 00007fcd1bf46ee7
R10: 0000000000000000 R11: 0000000000000293 R12: 00007fcd1c83941c
R13: 000000000000006e R14: 00007fff44b74b70 R15: 00007fff44b74c58
 </TASK>
----------------
Code disassembly (best guess):
   0:	49 89 c4             	mov    %rax,%r12
   3:	31 ff                	xor    %edi,%edi
   5:	48 89 c6             	mov    %rax,%rsi
   8:	e8 77 fe 99 ff       	call   0xff99fe84
   d:	4d 85 ed             	test   %r13,%r13
  10:	74 57                	je     0x69
  12:	4d 85 e4             	test   %r12,%r12
  15:	78 52                	js     0x69
  17:	e8 88 fa 99 ff       	call   0xff99faa4
  1c:	48 8b 44 24 20       	mov    0x20(%rsp),%rax
  21:	80 3c 18 00          	cmpb   $0x0,(%rax,%rbx,1)
  25:	4c 8b 6c 24 28       	mov    0x28(%rsp),%r13
* 2a:	74 0a                	je     0x36 <-- trapping instruction
  2c:	48 8d 7c 24 60       	lea    0x60(%rsp),%rdi
  31:	e8 ae 52 f1 ff       	call   0xfff152e4
  36:	48 8b 5c 24 60       	mov    0x60(%rsp),%rbx
  3b:	4c 89 f8             	mov    %r15,%rax
  3e:	48                   	rex.W
  3f:	c1                   	.byte 0xc1