============================================ WARNING: possible recursive locking detected 6.9.0-syzkaller-12162-gf85af9d955ac #0 Not tainted -------------------------------------------- udevd/5102 is trying to acquire lock: ffff8880790ae1d8 (&qs->lock){..-.}-{2:2}, at: __queue_map_get+0x14b/0x4d0 kernel/bpf/queue_stack_maps.c:105 but task is already holding lock: ffff8880790ae1d8 (&qs->lock){..-.}-{2:2}, at: queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&qs->lock); lock(&qs->lock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by udevd/5102: #0: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #0: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x24c/0x5a0 kernel/trace/bpf_trace.c:2445 #1: ffff8880790ae1d8 (&qs->lock){..-.}-{2:2}, at: queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 #2: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #2: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #2: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #2: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2444 stack backtrace: CPU: 1 PID: 5102 Comm: udevd Not tainted 6.9.0-syzkaller-12162-gf85af9d955ac #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3856 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __queue_map_get+0x14b/0x4d0 kernel/bpf/queue_stack_maps.c:105 bpf_prog_94b194d4ebfffdd5+0x45/0x49 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2444 trace_contention_end+0x114/0x140 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0xb81/0xdc0 kernel/locking/qspinlock.c:557 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [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+0x272/0x370 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xe1/0x120 kernel/locking/spinlock.c:162 queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 bpf_prog_216c997a1f42e404+0x3f/0x43 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline] bpf_trace_run3+0x33a/0x5a0 kernel/trace/bpf_trace.c:2445 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline] kmem_cache_free+0x2a9/0x350 mm/slub.c:4510 flock_lock_inode+0xf94/0x1460 fs/locks.c:1141 locks_remove_flock fs/locks.c:2658 [inline] locks_remove_file+0x3ff/0x10c0 fs/locks.c:2700 __fput+0x36a/0x8b0 fs/file_table.c:414 __do_sys_close fs/open.c:1555 [inline] __se_sys_close fs/open.c:1540 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1540 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6e181170a8 Code: 48 8b 05 83 9d 0d 00 64 c7 00 16 00 00 00 83 c8 ff 48 83 c4 20 5b c3 64 8b 04 25 18 00 00 00 85 c0 75 20 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 5b 48 8b 15 51 9d 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffeff86f6b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 00007f6e18495ae0 RCX: 00007f6e181170a8 RDX: 0000559599503177 RSI: 00007ffeff86eeb8 RDI: 0000000000000008 RBP: 00005590c05c0d00 R08: 0000000000000006 R09: cba34cc857a54a12 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000002 R13: 00005590c05b5fd0 R14: 0000000000000008 R15: 00005590c059f910