============================================ WARNING: possible recursive locking detected 5.19.0-syzkaller-13930-g7ebfc85e2cd7 #0 Not tainted -------------------------------------------- syz-executor.1/21684 is trying to acquire lock: ffffffff8cd7d238 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] ffffffff8cd7d238 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:374 but task is already holding lock: ffffffff8cd7d238 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] ffffffff8cd7d238 (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.1/21684: #0: ffff88807d196cb8 (&child->perf_event_mutex){+.+.}-{3:3}, at: perf_event_exit_task+0xa3/0xb80 kernel/events/core.c:12810 #1: ffffffff8cd207a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:279 #2: ffffffff8cd7d238 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] #2: ffffffff8cd7d238 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:374 #3: ffffffff8cd207a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:279 stack backtrace: CPU: 1 PID: 21684 Comm: syz-executor.1 Not tainted 5.19.0-syzkaller-13930-g7ebfc85e2cd7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 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:2988 [inline] check_deadlock kernel/locking/lockdep.c:3031 [inline] validate_chain+0x4897/0x6600 kernel/locking/lockdep.c:3816 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5053 lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5666 __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:903 [inline] __bpf_prog_run include/linux/filter.h:594 [inline] bpf_prog_run include/linux/filter.h:601 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2046 [inline] bpf_trace_run2+0x18a/0x320 kernel/trace/bpf_trace.c:2083 trace_contention_end+0x168/0x190 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+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:903 [inline] __bpf_prog_run include/linux/filter.h:594 [inline] bpf_prog_run include/linux/filter.h:601 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2046 [inline] bpf_trace_run2+0x18a/0x320 kernel/trace/bpf_trace.c:2083 trace_contention_end+0x122/0x140 include/trace/events/lock.h:122 __mutex_lock_common+0x453/0x26c0 kernel/locking/mutex.c:612 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 perf_event_exit_task+0xa3/0xb80 kernel/events/core.c:12810 do_exit+0x56e/0x20a0 kernel/exit.c:804 do_group_exit+0x23b/0x2f0 kernel/exit.c:925 get_signal+0x172f/0x1780 kernel/signal.c:2857 arch_do_signal_or_restart+0x8d/0x750 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop+0x74/0x160 kernel/entry/common.c:166 exit_to_user_mode_prepare+0xad/0x110 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x2e/0x60 kernel/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fddb9c89279 Code: Unable to access opcode bytes at RIP 0x7fddb9c8924f. RSP: 002b:00007fddbadcc218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fddb9d9bf88 RCX: 00007fddb9c89279 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fddb9d9bf88 RBP: 00007fddb9d9bf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fddb9d9bf8c R13: 00007fff90db720f R14: 00007fddbadcc300 R15: 0000000000022000