============================================ WARNING: possible recursive locking detected 6.0.0-rc6-syzkaller-00210-gbf682942cd26 #0 Not tainted -------------------------------------------- udevd/2975 is trying to acquire lock: ffffffff8cd7d4f8 (trace_printk_lock){-.-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] ffffffff8cd7d4f8 (trace_printk_lock){-.-.}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:374 but task is already holding lock: ffffffff8cd7d4f8 (trace_printk_lock){-.-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] ffffffff8cd7d4f8 (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 3 locks held by udevd/2975: #0: ffffffff8cd208a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:279 #1: ffffffff8cd7d4f8 (trace_printk_lock){-.-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] #1: ffffffff8cd7d4f8 (trace_printk_lock){-.-.}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:374 #2: ffffffff8cd208a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:279 stack backtrace: CPU: 0 PID: 2975 Comm: udevd Not tainted 6.0.0-rc6-syzkaller-00210-gbf682942cd26 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 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_run3+0x1bc/0x350 kernel/trace/bpf_trace.c:2084 __bpf_trace_kmem_cache_free+0x99/0xc0 include/trace/events/kmem.h:150 trace_kmem_cache_free+0xb5/0xd0 include/trace/events/kmem.h:150 kmem_cache_free+0x4a/0x1d0 mm/slub.c:3555 do_sys_openat2+0x428/0x500 fs/open.c:1322 do_sys_open fs/open.c:1329 [inline] __do_sys_openat fs/open.c:1345 [inline] __se_sys_openat fs/open.c:1340 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1340 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+0x63/0xcd RIP: 0033:0x7f771712a5a4 Code: f9 41 89 f0 41 83 e2 40 75 2c 89 f0 25 00 00 41 00 3d 00 00 41 00 74 1e 44 89 c2 4c 89 ce bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 2c c3 0f 1f 00 48 8d 44 24 08 c7 44 24 b8 10 RSP: 002b:00007ffef9a018e8 EFLAGS: 00000287 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000559b006a2750 RCX: 00007f771712a5a4 RDX: 0000000000090800 RSI: 0000559b006b9120 RDI: 00000000ffffff9c RBP: 0000559b0072d490 R08: 0000000000090800 R09: 0000559b006b9120 R10: 0000000000000000 R11: 0000000000000287 R12: 0000559b006b9120 R13: 00000000000000fe R14: 00007ffef9a01940 R15: 0000000000000000