FAULT_INJECTION: forcing a failure. name fail_usercopy, interval 1, probability 0, space 0, times 0 ============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.0.24/6553 is trying to acquire lock: ffffffff8df317b8 ((console_sem).lock){-...}-{2:2}, at: down_trylock+0x20/0xb0 kernel/locking/semaphore.c:176 but task is already holding lock: ffffffff8df317b8 ((console_sem).lock){-...}-{2:2}, at: down+0x39/0xd0 kernel/locking/semaphore.c:96 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock((console_sem).lock); lock((console_sem).lock); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by syz.0.24/6553: #0: ffffffff8df317b8 ((console_sem).lock){-...}-{2:2}, at: down+0x39/0xd0 kernel/locking/semaphore.c:96 #1: ffffffff8df3d5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #1: ffffffff8df3d5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #1: ffffffff8df3d5a0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2074 [inline] #1: ffffffff8df3d5a0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x186/0x4b0 kernel/trace/bpf_trace.c:2116 stack backtrace: CPU: 1 UID: 0 PID: 6553 Comm: syz.0.24 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_deadlock_bug+0x28b/0x2a0 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain+0x1a3f/0x2140 kernel/locking/lockdep.c:3895 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 down_trylock+0x20/0xb0 kernel/locking/semaphore.c:176 __down_trylock_console_sem+0xd0/0x1e0 kernel/printk/printk.c:327 console_trylock kernel/printk/printk.c:2841 [inline] console_trylock_spinning kernel/printk/printk.c:1982 [inline] vprintk_emit+0x213/0x590 kernel/printk/printk.c:2422 _printk+0xcf/0x120 kernel/printk/printk.c:2448 fail_dump lib/fault-inject.c:66 [inline] should_fail_ex+0x3f5/0x560 lib/fault-inject.c:174 strncpy_from_user+0x36/0x290 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x72/0x150 mm/maccess.c:192 bpf_trace_copy_string kernel/bpf/helpers.c:754 [inline] bpf_bprintf_prepare+0xb91/0x13a0 kernel/bpf/helpers.c:972 ____bpf_trace_printk kernel/trace/bpf_trace.c:372 [inline] bpf_trace_printk+0xdb/0x190 kernel/trace/bpf_trace.c:362 bpf_prog_930ede9872f2967c+0x3e/0x44 bpf_dispatcher_nop_func include/linux/bpf.h:1357 [inline] __bpf_prog_run include/linux/filter.h:721 [inline] bpf_prog_run include/linux/filter.h:728 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline] bpf_trace_run2+0x284/0x4b0 kernel/trace/bpf_trace.c:2116 __bpf_trace_contention_begin+0xdc/0x130 include/trace/events/lock.h:95 __do_trace_contention_begin include/trace/events/lock.h:95 [inline] trace_contention_begin include/trace/events/lock.h:95 [inline] __down_common+0x5ad/0x6a0 kernel/locking/semaphore.c:292 down+0x80/0xd0 kernel/locking/semaphore.c:100 console_lock+0x58/0x90 kernel/printk/printk.c:2822 do_fb_ioctl+0x509/0x750 drivers/video/fbdev/core/fb_chrdev.c:123 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ffb5a18eb69 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:00007ffb5af95038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffb5a3b5fa0 RCX: 00007ffb5a18eb69 RDX: 0000200000000080 RSI: 0000000000004606 RDI: 0000000000000005 RBP: 00007ffb5af95090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 00007ffb5a3b5fa0 R15: 00007fffafdbe5b8