============================================ WARNING: possible recursive locking detected 6.1.0-rc7-syzkaller-00190-g97ee9d1c1696 #0 Not tainted -------------------------------------------- syz-executor.2/20754 is trying to acquire lock: ffffffff8d3813d8 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] ffffffff8d3813d8 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:376 but task is already holding lock: ffffffff8d3813d8 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] ffffffff8d3813d8 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:376 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 3 locks held by syz-executor.2/20754: #0: ffffffff8d323de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:303 #1: ffffffff8d3813d8 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] #1: ffffffff8d3813d8 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:376 #2: ffffffff8d323de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:303 stack backtrace: CPU: 0 PID: 20754 Comm: syz-executor.2 Not tainted 6.1.0-rc7-syzkaller-00190-g97ee9d1c1696 #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+0x1e3/0x2cb lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2990 [inline] check_deadlock kernel/locking/lockdep.c:3033 [inline] validate_chain+0x4721/0x6470 kernel/locking/lockdep.c:3818 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055 lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5668 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:376 bpf_prog_0605f9f479290f07+0x2f/0x33 bpf_dispatcher_nop_func include/linux/bpf.h:968 [inline] __bpf_prog_run include/linux/filter.h:600 [inline] bpf_prog_run include/linux/filter.h:607 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2254 [inline] bpf_trace_run2+0x1c2/0x3b0 kernel/trace/bpf_trace.c:2293 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:95 [inline] trace_contention_begin+0x1c9/0x210 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x10f/0xc60 kernel/locking/qspinlock.c:405 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath+0x42/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x264/0x360 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xdd/0x120 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:376 bpf_prog_0605f9f479290f07+0x2f/0x33 bpf_dispatcher_nop_func include/linux/bpf.h:968 [inline] __bpf_prog_run include/linux/filter.h:600 [inline] bpf_prog_run include/linux/filter.h:607 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2254 [inline] bpf_trace_run2+0x1c2/0x3b0 kernel/trace/bpf_trace.c:2293 __bpf_trace_sys_exit+0x60/0x70 include/trace/events/syscalls.h:44 __traceiter_sys_exit+0x2f/0x50 include/trace/events/syscalls.h:44 trace_sys_exit+0xb8/0xe0 include/trace/events/syscalls.h:44 syscall_exit_work+0x4a/0xe0 kernel/entry/common.c:247 syscall_exit_to_user_mode_prepare+0x6b/0xc0 kernel/entry/common.c:278 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0xa/0x60 kernel/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f9ffc68c0d9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9ffd3a0168 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: 0000000000000007 RBX: 00007f9ffc7abf80 RCX: 00007f9ffc68c0d9 RDX: 0000000000000010 RSI: 0000000020002040 RDI: 0000000000000011 RBP: 00007f9ffc6e7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff4ea3e32f R14: 00007f9ffd3a0300 R15: 0000000000022000