============================================ WARNING: possible recursive locking detected 6.2.0-rc3-syzkaller-00021-g7dd4b804e080 #0 Not tainted -------------------------------------------- syz-executor.1/16064 is trying to acquire lock: ffffffff8d580858 (trace_printk_lock){-.-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:391 [inline] ffffffff8d580858 (trace_printk_lock){-.-.}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:377 but task is already holding lock: ffffffff8d580858 (trace_printk_lock){-.-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:391 [inline] ffffffff8d580858 (trace_printk_lock){-.-.}-{2:2}, at: bpf_trace_printk+0x151/0x200 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.1/16064: #0: ffffffff8d523800 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:324 #1: ffffffff8d580858 (trace_printk_lock){-.-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:391 [inline] #1: ffffffff8d580858 (trace_printk_lock){-.-.}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:377 #2: ffffffff8d523800 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:324 stack backtrace: CPU: 0 PID: 16064 Comm: syz-executor.1 Not tainted 6.2.0-rc3-syzkaller-00021-g7dd4b804e080 #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+0x1e3/0x2d0 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2990 [inline] check_deadlock kernel/locking/lockdep.c:3033 [inline] validate_chain+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:391 [inline] bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:377 bpf_prog_0605f9f479290f07+0x2f/0x33 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:2263 [inline] bpf_trace_run2+0x1c2/0x3b0 kernel/trace/bpf_trace.c:2302 trace_contention_end+0x1c6/0x210 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x93f/0xc60 kernel/locking/qspinlock.c:560 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+0x28e/0x3a0 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:391 [inline] bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:377 bpf_prog_0605f9f479290f07+0x2f/0x33 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:2263 [inline] bpf_trace_run2+0x1c2/0x3b0 kernel/trace/bpf_trace.c:2302 __bpf_trace_sys_exit+0x60/0x70 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: 0033:0x7f78ee68d4f1 Code: 48 85 ff 74 3d 48 85 f6 74 38 48 83 ee 10 48 89 4e 08 48 89 3e 48 89 d7 4c 89 c2 4d 89 c8 4c 8b 54 24 08 b8 38 00 00 00 0f 05 <48> 85 c0 7c 13 74 01 c3 31 ed 58 5f ff d0 48 89 c7 b8 3c 00 00 00 RSP: 002b:00007ffc8a434c08 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: 00000000000014dd RBX: 00007f78ef313700 RCX: 00007f78ee68d4f1 RDX: 00007f78ef3139d0 RSI: 00007f78ef3132f0 RDI: 00000000003d0f00 RBP: 00007ffc8a434e50 R08: 00007f78ef313700 R09: 00007f78ef313700 R10: 00007f78ef3139d0 R11: 0000000000000206 R12: 00007ffc8a434cbe R13: 00007ffc8a434cbf R14: 00007f78ef313300 R15: 0000000000022000