============================================ WARNING: possible recursive locking detected 6.10.0-rc2-syzkaller-00001-ge377d803b65e #0 Not tainted -------------------------------------------- udevd/5414 is trying to acquire lock: ffff88807eff51f8 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:462 but task is already holding lock: ffff88807eff59f8 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:462 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&trie->lock); lock(&trie->lock); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by udevd/5414: #0: ffff88801f3e8f08 (kn->active#5){.+.+}-{0:0}, at: kernfs_fop_open+0x93/0xd10 fs/kernfs/file.c:601 #1: ffff8880162ecc38 (&kernfs_locks->open_file_mutex[count]){+.+.}-{3:3}, at: kernfs_open_file_mutex_lock fs/kernfs/file.c:56 [inline] #1: ffff8880162ecc38 (&kernfs_locks->open_file_mutex[count]){+.+.}-{3:3}, at: kernfs_get_open_node fs/kernfs/file.c:520 [inline] #1: ffff8880162ecc38 (&kernfs_locks->open_file_mutex[count]){+.+.}-{3:3}, at: kernfs_fop_open+0x74d/0xd10 fs/kernfs/file.c:700 #2: ffffffff8e333f60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #2: ffffffff8e333f60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #2: ffffffff8e333f60 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2409 [inline] #2: ffffffff8e333f60 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x21f/0x570 kernel/trace/bpf_trace.c:2451 #3: ffff88807eff59f8 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:462 #4: ffffffff8e333f60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #4: ffffffff8e333f60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #4: ffffffff8e333f60 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2409 [inline] #4: ffffffff8e333f60 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x21f/0x570 kernel/trace/bpf_trace.c:2451 stack backtrace: CPU: 1 PID: 5414 Comm: udevd Not tainted 6.10.0-rc2-syzkaller-00001-ge377d803b65e #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 trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:462 bpf_prog_1db1603a7cfa36fb+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:2410 [inline] bpf_trace_run2+0x30d/0x570 kernel/trace/bpf_trace.c:2451 __traceiter_contention_end+0x7b/0xb0 include/trace/events/lock.h:122 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 trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:462 bpf_prog_1db1603a7cfa36fb+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:2410 [inline] bpf_trace_run2+0x30d/0x570 kernel/trace/bpf_trace.c:2451 __traceiter_contention_end+0x7b/0xb0 include/trace/events/lock.h:122 trace_contention_end+0xf5/0x120 include/trace/events/lock.h:122 __mutex_lock_common kernel/locking/mutex.c:617 [inline] __mutex_lock+0x2e5/0xd70 kernel/locking/mutex.c:752 kernfs_open_file_mutex_lock fs/kernfs/file.c:56 [inline] kernfs_get_open_node fs/kernfs/file.c:520 [inline] kernfs_fop_open+0x74d/0xd10 fs/kernfs/file.c:700 do_dentry_open+0x95a/0x1720 fs/open.c:955 do_open fs/namei.c:3650 [inline] path_openat+0x289f/0x3280 fs/namei.c:3807 do_filp_open+0x235/0x490 fs/namei.c:3834 do_sys_openat2+0x13e/0x1d0 fs/open.c:1405 do_sys_open fs/open.c:1420 [inline] __do_sys_openat fs/open.c:1436 [inline] __se_sys_openat fs/open.c:1431 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1431 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: 0033:0x7f7f17b169a4 Code: 24 20 48 8d 44 24 30 48 89 44 24 28 64 8b 04 25 18 00 00 00 85 c0 75 2c 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 60 48 8b 15 55 a4 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffdf6fcc1a0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f7f17b169a4 RDX: 0000000000080000 RSI: 00007ffdf6fcc2d8 RDI: 00000000ffffff9c RBP: 00007ffdf6fcc2d8 R08: 0000000000000008 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080000 R13: 000056111e750b42 R14: 0000000000000001 R15: 000056111e76c160