============================================ WARNING: possible recursive locking detected 6.1.0-rc3-syzkaller-00139-g9521c9d6a53d #0 Not tainted -------------------------------------------- udevd/2975 is trying to acquire lock: ffffffff8c011718 (trace_printk_lock){..-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] ffffffff8c011718 (trace_printk_lock){..-.}-{2:2}, at: bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:376 but task is already holding lock: ffffffff8c011718 (trace_printk_lock){..-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] ffffffff8c011718 (trace_printk_lock){..-.}-{2:2}, at: bpf_trace_printk+0xcf/0x170 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 3 locks held by udevd/2975: #0: ffffffff8bf88940 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2249 [inline] #0: ffffffff8bf88940 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xb9/0x3d0 kernel/trace/bpf_trace.c:2293 #1: ffffffff8c011718 (trace_printk_lock){..-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] #1: ffffffff8c011718 (trace_printk_lock){..-.}-{2:2}, at: bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:376 #2: ffffffff8bf88940 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2249 [inline] #2: ffffffff8bf88940 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xb9/0x3d0 kernel/trace/bpf_trace.c:2293 stack backtrace: CPU: 1 PID: 2975 Comm: udevd Not tainted 6.1.0-rc3-syzkaller-00139-g9521c9d6a53d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2990 [inline] check_deadlock kernel/locking/lockdep.c:3033 [inline] validate_chain kernel/locking/lockdep.c:3818 [inline] __lock_acquire.cold+0x116/0x3a7 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1df/0x630 kernel/locking/lockdep.c:5633 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:376 bpf_prog_0605f9f479290f07+0x2f/0x33 bpf_dispatcher_nop_func include/linux/bpf.h:964 [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:2254 [inline] bpf_trace_run2+0x14d/0x3d0 kernel/trace/bpf_trace.c:2293 __bpf_trace_contention_begin+0xb5/0xf0 include/trace/events/lock.h:95 __traceiter_contention_begin+0x56/0x90 include/trace/events/lock.h:95 trace_contention_begin.constprop.0+0x143/0x240 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x103/0xb50 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+0x200/0x2a0 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0x41/0x50 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:376 bpf_prog_0605f9f479290f07+0x2f/0x33 bpf_dispatcher_nop_func include/linux/bpf.h:964 [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:2254 [inline] bpf_trace_run2+0x14d/0x3d0 kernel/trace/bpf_trace.c:2293 __traceiter_sys_exit+0x29/0x40 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+0x1df/0x280 kernel/entry/common.c:278 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x9/0x50 kernel/entry/common.c:296 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f2618325697 Code: 25 00 00 41 00 3d 00 00 41 00 74 37 64 8b 04 25 18 00 00 00 85 c0 75 5b 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 85 00 00 00 48 83 c4 68 5d 41 5c c3 0f 1f RSP: 002b:00007fffe0f52650 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: 000000000000000c RBX: 00007fffe0f52938 RCX: 00007f2618325697 RDX: 0000000000080141 RSI: 000055a0da10d0d8 RDI: 00000000ffffff9c RBP: 000055a0da10d0d8 R08: 00000000ffffffff R09: 0000000000000000 R10: 00000000000001a4 R11: 0000000000000246 R12: 0000000000080141 R13: ffffffffffffffff R14: 00000000ffffffff R15: 00000000ffffffff