============================================ WARNING: possible recursive locking detected 6.1.0-syzkaller-14017-g45435d8da71f #0 Not tainted -------------------------------------------- sshd/5073 is trying to acquire lock: ffffffff8c81a238 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:391 [inline] ffffffff8c81a238 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0xd3/0x170 kernel/trace/bpf_trace.c:377 but task is already holding lock: ffffffff8c81a238 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:391 [inline] ffffffff8c81a238 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0xd3/0x170 kernel/trace/bpf_trace.c:377 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(trace_printk_lock); lock(trace_printk_lock); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by sshd/5073: #0: ffff88801818b468 (&pipe->mutex/1){+.+.}-{3:3}, at: __pipe_lock fs/pipe.c:103 [inline] #0: ffff88801818b468 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_read+0x13d/0x1110 fs/pipe.c:244 #1: ffffffff8c7917c0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2258 [inline] #1: ffffffff8c7917c0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xbd/0x3d0 kernel/trace/bpf_trace.c:2302 #2: ffffffff8c81a238 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:391 [inline] #2: ffffffff8c81a238 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0xd3/0x170 kernel/trace/bpf_trace.c:377 #3: ffffffff8c7917c0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2258 [inline] #3: ffffffff8c7917c0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xbd/0x3d0 kernel/trace/bpf_trace.c:2302 stack backtrace: CPU: 0 PID: 5073 Comm: sshd Not tainted 6.1.0-syzkaller-14017-g45435d8da71f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2990 [inline] check_deadlock kernel/locking/lockdep.c:3033 [inline] validate_chain kernel/locking/lockdep.c:3818 [inline] __lock_acquire.cold+0x116/0x3a7 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:391 [inline] bpf_trace_printk+0xd3/0x170 kernel/trace/bpf_trace.c:377