============================================ WARNING: possible recursive locking detected 6.1.52-syzkaller #0 Not tainted -------------------------------------------- syz-executor.2/3186 is trying to acquire lock: ffffffff8319a6a8 (trace_printk_lock){..-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] ffffffff8319a6a8 (trace_printk_lock){..-.}-{2:2}, at: bpf_trace_printk+0x5f/0x130 kernel/trace/bpf_trace.c:376 but task is already holding lock: ffffffff8319a6a8 (trace_printk_lock){..-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] ffffffff8319a6a8 (trace_printk_lock){..-.}-{2:2}, at: bpf_trace_printk+0x5f/0x130 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 4 locks held by syz-executor.2/3186: #0: ffff88811cc39448 (&child->perf_event_mutex){+.+.}-{3:3}, at: perf_event_exit_task+0x30/0x330 kernel/events/core.c:12977 #1: ffffffff83186d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 include/trace/events/initcall.h:48 #2: ffffffff8319a6a8 (trace_printk_lock){..-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] #2: ffffffff8319a6a8 (trace_printk_lock){..-.}-{2:2}, at: bpf_trace_printk+0x5f/0x130 kernel/trace/bpf_trace.c:376 #3: ffffffff83186d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 include/trace/events/initcall.h:48 stack backtrace: CPU: 1 PID: 3186 Comm: syz-executor.2 Not tainted 6.1.52-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x89/0xd7 lib/dump_stack.c:106 __lock_acquire+0x73d/0x2830 lock_acquire+0xe3/0x270 kernel/locking/lockdep.c:5661 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x5d/0x90 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] bpf_trace_printk+0x5f/0x130 kernel/trace/bpf_trace.c:376 ___bpf_prog_run+0x816/0x1b10 kernel/bpf/core.c:1819 __bpf_prog_run32+0xb7/0xe0 kernel/bpf/core.c:2040 bpf_dispatcher_nop_func include/linux/bpf.h:974 [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:2275 [inline] bpf_trace_run2+0x9e/0x160 kernel/trace/bpf_trace.c:2314 __traceiter_contention_end+0x26/0x40 include/trace/events/lock.h:122 trace_contention_end include/trace/events/lock.h:122 [inline] __pv_queued_spin_lock_slowpath+0x468/0x480 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+0x95/0xa0 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0x69/0x90 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] bpf_trace_printk+0x5f/0x130 kernel/trace/bpf_trace.c:376 ___bpf_prog_run+0x816/0x1b10 kernel/bpf/core.c:1819 __bpf_prog_run32+0xb7/0xe0 kernel/bpf/core.c:2040 bpf_dispatcher_nop_func include/linux/bpf.h:974 [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:2275 [inline] bpf_trace_run2+0x9e/0x160 kernel/trace/bpf_trace.c:2314 __traceiter_contention_end+0x26/0x40 include/trace/events/lock.h:122 trace_contention_end include/trace/events/lock.h:122 [inline] __mutex_lock_common kernel/locking/mutex.c:612 [inline] __mutex_lock+0x808/0x970 kernel/locking/mutex.c:747 perf_event_exit_task+0x30/0x330 kernel/events/core.c:12977 do_exit+0x2e4/0xa30 kernel/exit.c:878 do_group_exit+0x97/0xa0 kernel/exit.c:1019 __do_sys_exit_group kernel/exit.c:1030 [inline] __se_sys_exit_group kernel/exit.c:1028 [inline] __x64_sys_exit_group+0xe/0x10 kernel/exit.c:1028 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f92fd3dd959 Code: Unable to access opcode bytes at 0x7f92fd3dd92f. RSP: 002b:00007ffc531a2038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000000000000001e RCX: 00007f92fd3dd959 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: 00007f92fd4fcf8c R09: 0000000000000000 R10: 0000001b2d160000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000