FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
======================================================
WARNING: possible circular locking dependency detected
5.15.186-syzkaller #0 Not tainted
------------------------------------------------------
syz.0.1682/8997 is trying to acquire lock:
ffffffff8c1109e0 (console_owner){-...}-{0:0}, at: console_lock_spinning_enable+0x2c/0x60 kernel/printk/printk.c:1802

but task is already holding lock:
ffff8880622da1b8 (&trie->lock){..-.}-{2:2}, at: trie_update_elem+0xc7/0xc50 kernel/bpf/lpm_trie.c:323

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #5 (&trie->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
       trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467
       0xffffffffa0028dde
       bpf_dispatcher_nop_func include/linux/bpf.h:790 [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
       __traceiter_sched_switch+0x83/0xb0 include/trace/events/sched.h:220
       trace_sched_switch include/trace/events/sched.h:220 [inline]
       __schedule+0x1d8b/0x43b0 kernel/sched/core.c:6373
       preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6552
       preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6577
       preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
       try_to_wake_up+0x701/0x1050 kernel/sched/core.c:4152
       wake_up_process kernel/sched/core.c:4215 [inline]
       wake_up_q+0x78/0xc0 kernel/sched/core.c:953
       futex_wake+0x49f/0x530 kernel/futex/core.c:1702
       do_futex+0xcde/0x1240 kernel/futex/core.c:3987
       __do_sys_futex kernel/futex/core.c:4059 [inline]
       __se_sys_futex+0x3a3/0x430 kernel/futex/core.c:4040
       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

-> #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:4466
       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:4030
       __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
       __unwind_start+0x3c/0x740 arch/x86/kernel/unwind_orc.c:633
       unwind_start arch/x86/include/asm/unwind.h:60 [inline]
       arch_stack_walk+0xda/0x140 arch/x86/kernel/stacktrace.c:24
       stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
       kasan_save_stack mm/kasan/common.c:38 [inline]
       kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
       kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
       ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
       kasan_slab_free include/linux/kasan.h:230 [inline]
       slab_free_hook mm/slub.c:1705 [inline]
       slab_free_freelist_hook+0xea/0x170 mm/slub.c:1731
       slab_free mm/slub.c:3499 [inline]
       kmem_cache_free+0x8f/0x210 mm/slub.c:3515
       remove_vma mm/mmap.c:187 [inline]
       exit_mmap+0x4d8/0x5f0 mm/mmap.c:3223
       __mmput+0x115/0x3b0 kernel/fork.c:1127
       exit_mm+0x567/0x6c0 kernel/exit.c:550
       do_exit+0x5a1/0x20a0 kernel/exit.c:870
       do_group_exit+0x12e/0x300 kernel/exit.c:997
       __do_sys_exit_group kernel/exit.c:1008 [inline]
       __se_sys_exit_group kernel/exit.c:1006 [inline]
       __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006
       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

-> #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:3363
       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_lock_spinning_enable+0x51/0x60 kernel/printk/printk.c:1805
       console_unlock+0x9f8/0x1200 kernel/printk/printk.c:2741
       vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
       _printk+0xcc/0x110 kernel/printk/printk.c:2299
       fail_dump lib/fault-inject.c:45 [inline]
       should_fail+0x36d/0x4c0 lib/fault-inject.c:146
       should_failslab+0x5/0x20 mm/slab_common.c:1350
       slab_pre_alloc_hook+0x51/0xc0 mm/slab.h:494
       slab_alloc_node mm/slub.c:3134 [inline]
       __kmalloc_node+0x6e/0x3b0 mm/slub.c:4451
       kmalloc_node include/linux/slab.h:627 [inline]
       bpf_map_kmalloc_node+0xba/0x140 kernel/bpf/syscall.c:430
       lpm_trie_node_alloc kernel/bpf/lpm_trie.c:290 [inline]
       trie_update_elem+0x8ba/0xc50 kernel/bpf/lpm_trie.c:416
       bpf_map_update_value+0x591/0x670 kernel/bpf/syscall.c:221
       generic_map_update_batch+0x525/0x7c0 kernel/bpf/syscall.c:1424
       bpf_map_do_batch+0x466/0x600 kernel/bpf/syscall.c:-1
       __sys_bpf+0x601/0x670 kernel/bpf/syscall.c:-1
       __do_sys_bpf kernel/bpf/syscall.c:4755 [inline]
       __se_sys_bpf kernel/bpf/syscall.c:4753 [inline]
       __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753
       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

other info that might help us debug this:

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

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

3 locks held by syz.0.1682/8997:
 #0: ffffffff8c11bfa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311
 #1: ffff8880622da1b8 (&trie->lock){..-.}-{2:2}, at: trie_update_elem+0xc7/0xc50 kernel/bpf/lpm_trie.c:323
 #2: ffffffff8c110ac0 (console_lock){+.+.}-{0:0}, at: vprintk_emit+0xa7/0x150 kernel/printk/printk.c:2273

stack backtrace:
CPU: 0 PID: 8997 Comm: syz.0.1682 Not tainted 5.15.186-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 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_lock_spinning_enable+0x51/0x60 kernel/printk/printk.c:1805
 console_unlock+0x9f8/0x1200 kernel/printk/printk.c:2741
 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
 _printk+0xcc/0x110 kernel/printk/printk.c:2299
 fail_dump lib/fault-inject.c:45 [inline]
 should_fail+0x36d/0x4c0 lib/fault-inject.c:146
 should_failslab+0x5/0x20 mm/slab_common.c:1350
 slab_pre_alloc_hook+0x51/0xc0 mm/slab.h:494
 slab_alloc_node mm/slub.c:3134 [inline]
 __kmalloc_node+0x6e/0x3b0 mm/slub.c:4451
 kmalloc_node include/linux/slab.h:627 [inline]
 bpf_map_kmalloc_node+0xba/0x140 kernel/bpf/syscall.c:430
 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:290 [inline]
 trie_update_elem+0x8ba/0xc50 kernel/bpf/lpm_trie.c:416
 bpf_map_update_value+0x591/0x670 kernel/bpf/syscall.c:221
 generic_map_update_batch+0x525/0x7c0 kernel/bpf/syscall.c:1424
 bpf_map_do_batch+0x466/0x600 kernel/bpf/syscall.c:-1
 __sys_bpf+0x601/0x670 kernel/bpf/syscall.c:-1
 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4753 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753
 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
RIP: 0033:0x7fa862e78929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa860ce0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fa86309ffa0 RCX: 00007fa862e78929
RDX: 0000000000000038 RSI: 0000200000000240 RDI: 000000000000001a
RBP: 00007fa860ce0090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 0000000000000000 R14: 00007fa86309ffa0 R15: 00007ffde042a808
 </TASK>
CPU: 0 PID: 8997 Comm: syz.0.1682 Not tainted 5.15.186-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail+0x38c/0x4c0 lib/fault-inject.c:146
 should_failslab+0x5/0x20 mm/slab_common.c:1350
 slab_pre_alloc_hook+0x51/0xc0 mm/slab.h:494
 slab_alloc_node mm/slub.c:3134 [inline]
 __kmalloc_node+0x6e/0x3b0 mm/slub.c:4451
 kmalloc_node include/linux/slab.h:627 [inline]
 bpf_map_kmalloc_node+0xba/0x140 kernel/bpf/syscall.c:430
 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:290 [inline]
 trie_update_elem+0x8ba/0xc50 kernel/bpf/lpm_trie.c:416
 bpf_map_update_value+0x591/0x670 kernel/bpf/syscall.c:221
 generic_map_update_batch+0x525/0x7c0 kernel/bpf/syscall.c:1424
 bpf_map_do_batch+0x466/0x600 kernel/bpf/syscall.c:-1
 __sys_bpf+0x601/0x670 kernel/bpf/syscall.c:-1
 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4753 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753
 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
RIP: 0033:0x7fa862e78929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa860ce0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fa86309ffa0 RCX: 00007fa862e78929
RDX: 0000000000000038 RSI: 0000200000000240 RDI: 000000000000001a
RBP: 00007fa860ce0090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 0000000000000000 R14: 00007fa86309ffa0 R15: 00007ffde042a808
 </TASK>