============================================ WARNING: possible recursive locking detected 5.19.0-rc2-syzkaller-00052-g979086f5e006 #0 Not tainted -------------------------------------------- syz-executor.2/27514 is trying to acquire lock: ffffffff8cb7adb8 (trace_printk_lock){..-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] ffffffff8cb7adb8 (trace_printk_lock){..-.}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:374 but task is already holding lock: ffffffff8cb7adb8 (trace_printk_lock){..-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] ffffffff8cb7adb8 (trace_printk_lock){..-.}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:374 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 syz-executor.2/27514: #0: ffffffff8cb71d08 (event_mutex){+.+.}-{3:3}, at: __ftrace_set_clr_event kernel/trace/trace_events.c:1059 [inline] #0: ffffffff8cb71d08 (event_mutex){+.+.}-{3:3}, at: trace_set_clr_event+0xc0/0x130 kernel/trace/trace_events.c:1125 #1: ffffffff8cb1eca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:268 #2: ffffffff8cb7adb8 (trace_printk_lock){..-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] #2: ffffffff8cb7adb8 (trace_printk_lock){..-.}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:374 #3: ffffffff8cb1eca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:268 stack backtrace: CPU: 0 PID: 27514 Comm: syz-executor.2 Not tainted 5.19.0-rc2-syzkaller-00052-g979086f5e006 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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:2988 [inline] check_deadlock kernel/locking/lockdep.c:3031 [inline] validate_chain+0x485d/0x65c0 kernel/locking/lockdep.c:3816 __lock_acquire+0x129a/0x1f80 kernel/locking/lockdep.c:5053 lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5665 __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:388 [inline] bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:374 bpf_prog_0605f9f479290f07+0x2f/0x33 bpf_dispatcher_nop_func include/linux/bpf.h:869 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2046 [inline] bpf_trace_run2+0x18a/0x320 kernel/trace/bpf_trace.c:2083 trace_contention_begin+0x168/0x190 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:388 [inline] bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:374 bpf_prog_0605f9f479290f07+0x2f/0x33 bpf_dispatcher_nop_func include/linux/bpf.h:869 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2046 [inline] bpf_trace_run2+0x18a/0x320 kernel/trace/bpf_trace.c:2083 trace_contention_begin+0x116/0x140 include/trace/events/lock.h:95 __mutex_lock_common+0x1ef/0x26c0 kernel/locking/mutex.c:605 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 __ftrace_set_clr_event kernel/trace/trace_events.c:1059 [inline] trace_set_clr_event+0xc0/0x130 kernel/trace/trace_events.c:1125 __set_printk_clr_event kernel/trace/bpf_trace.c:417 [inline] bpf_get_trace_printk_proto+0x1e/0x80 kernel/trace/bpf_trace.c:423 bpf_tracing_func_proto+0xad/0x550 kernel/trace/bpf_trace.c:1221 check_helper_call+0x1da/0x66b0 kernel/bpf/verifier.c:7127 do_check+0x7787/0xe1c0 kernel/bpf/verifier.c:12218 do_check_common+0x857/0x16d0 kernel/bpf/verifier.c:14390 do_check_main kernel/bpf/verifier.c:14453 [inline] bpf_check+0x2c8e/0x13b70 kernel/bpf/verifier.c:15022 bpf_prog_load+0x1288/0x1b80 kernel/bpf/syscall.c:2575 __sys_bpf+0x3d3/0x6c0 kernel/bpf/syscall.c:4917 __do_sys_bpf kernel/bpf/syscall.c:5021 [inline] __se_sys_bpf kernel/bpf/syscall.c:5019 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5019 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7efcfb689109 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007efcfc764168 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007efcfb79bf60 RCX: 00007efcfb689109 RDX: 0000000000000048 RSI: 0000000020000080 RDI: 0000000000000005 RBP: 00007efcfb6e305d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc51a760df R14: 00007efcfc764300 R15: 0000000000022000