============================================ WARNING: possible recursive locking detected 6.2.0-rc8-syzkaller-00151-g925cf0457d7e #0 Not tainted -------------------------------------------- syz-executor.5/15470 is trying to acquire lock: ffffffff8cf82778 (trace_printk_lock){-.-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:391 [inline] ffffffff8cf82778 (trace_printk_lock){-.-.}-{2:2}, at: bpf_trace_printk+0x155/0x200 kernel/trace/bpf_trace.c:377 but task is already holding lock: ffffffff8cf82778 (trace_printk_lock){-.-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:391 [inline] ffffffff8cf82778 (trace_printk_lock){-.-.}-{2:2}, at: bpf_trace_printk+0x155/0x200 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 3 locks held by syz-executor.5/15470: #0: ffffffff8cf25780 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x40 include/linux/rcupdate.h:324 #1: ffffffff8cf82778 (trace_printk_lock){-.-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:391 [inline] #1: ffffffff8cf82778 (trace_printk_lock){-.-.}-{2:2}, at: bpf_trace_printk+0x155/0x200 kernel/trace/bpf_trace.c:377 #2: ffffffff8cf25780 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x40 include/linux/rcupdate.h:324 stack backtrace: CPU: 0 PID: 15470 Comm: syz-executor.5 Not tainted 6.2.0-rc8-syzkaller-00151-g925cf0457d7e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2990 [inline] check_deadlock kernel/locking/lockdep.c:3033 [inline] validate_chain+0x472a/0x58e0 kernel/locking/lockdep.c:3818 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5055 lock_acquire+0x235/0x630 kernel/locking/lockdep.c:5668 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:391 [inline] bpf_trace_printk+0x155/0x200 kernel/trace/bpf_trace.c:377 bpf_prog_0605f9f479290f07+0x37/0x3b bpf_dispatcher_nop_func include/linux/bpf.h:1082 [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:2267 [inline] bpf_trace_run2+0x1bf/0x3a0 kernel/trace/bpf_trace.c:2306 trace_contention_begin+0x1cf/0x220 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x115/0xc50 kernel/locking/qspinlock.c:405 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x297/0x3a0 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xe1/0x120 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:391 [inline] bpf_trace_printk+0x155/0x200 kernel/trace/bpf_trace.c:377 bpf_prog_0605f9f479290f07+0x37/0x3b bpf_dispatcher_nop_func include/linux/bpf.h:1082 [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:2267 [inline] bpf_trace_run2+0x1bf/0x3a0 kernel/trace/bpf_trace.c:2306 __bpf_trace_sys_exit+0x64/0x70 include/trace/events/syscalls.h:44 trace_sys_exit include/trace/events/syscalls.h:44 [inline] syscall_exit_work kernel/entry/common.c:247 [inline] syscall_exit_to_user_mode_prepare kernel/entry/common.c:278 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x26b/0x2e0 kernel/entry/common.c:296 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fb7a428c0f9 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:00007fb7a4feb218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000000 RBX: 00007fb7a43abf88 RCX: 00007fb7a428c0f9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb7a43abf88 RBP: 00007fb7a43abf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb7a43abf8c R13: 00007ffda7b7e7af R14: 00007fb7a4feb300 R15: 0000000000022000