============================================ WARNING: possible recursive locking detected 6.14.0-rc4-syzkaller-00859-gf77f12010f67 #0 Not tainted -------------------------------------------- syz-executor/6615 is trying to acquire lock: ffff8880120dea68 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x96/0x6d0 kernel/bpf/lpm_trie.c:470 but task is already holding lock: ffff888059af3a68 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x96/0x6d0 kernel/bpf/lpm_trie.c:470 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 4 locks held by syz-executor/6615: #0: ffff888030c6ad88 (&xt[i].mutex){+.+.}-{4:4}, at: xt_find_table_lock+0x4c/0x400 net/netfilter/x_tables.c:1243 #1: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #1: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2370 [inline] #1: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2412 #2: ffff888059af3a68 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x96/0x6d0 kernel/bpf/lpm_trie.c:470 #3: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #3: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2370 [inline] #3: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2412 stack backtrace: CPU: 0 UID: 0 PID: 6615 Comm: syz-executor Not tainted 6.14.0-rc4-syzkaller-00859-gf77f12010f67 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3039 check_deadlock kernel/locking/lockdep.c:3091 [inline] validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3893 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __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+0x96/0x6d0 kernel/bpf/lpm_trie.c:470 bpf_prog_2c29ac5cdc6b1842+0x43/0x47 bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2412 __bpf_trace_contention_end+0x170/0x230 include/trace/events/lock.h:122 __traceiter_contention_end+0x7b/0xb0 include/trace/events/lock.h:122 __do_trace_contention_end include/trace/events/lock.h:122 [inline] trace_contention_end+0x118/0x140 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0xb7e/0xdb0 kernel/locking/qspinlock.c:557 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:577 [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+0x96/0x6d0 kernel/bpf/lpm_trie.c:470 bpf_prog_2c29ac5cdc6b1842+0x43/0x47 bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2412 __bpf_trace_contention_end+0x170/0x230 include/trace/events/lock.h:122 __traceiter_contention_end+0x7b/0xb0 include/trace/events/lock.h:122 __do_trace_contention_end include/trace/events/lock.h:122 [inline] trace_contention_end+0xf9/0x120 include/trace/events/lock.h:122 __mutex_lock_common kernel/locking/mutex.c:594 [inline] __mutex_lock+0x38d/0x1010 kernel/locking/mutex.c:730 xt_find_table_lock+0x4c/0x400 net/netfilter/x_tables.c:1243 xt_request_find_table_lock+0x26/0x100 net/netfilter/x_tables.c:1285 get_info net/ipv6/netfilter/ip6_tables.c:979 [inline] do_ip6t_get_ctl+0x891/0x18b0 net/ipv6/netfilter/ip6_tables.c:1668 nf_getsockopt+0x299/0x2c0 net/netfilter/nf_sockopt.c:116 ipv6_getsockopt+0x23e/0x360 net/ipv6/ipv6_sockglue.c:1493 tcp_getsockopt+0x163/0x1c0 net/ipv4/tcp.c:4705 do_sock_getsockopt+0x38e/0x740 net/socket.c:2355 __sys_getsockopt net/socket.c:2384 [inline] __do_sys_getsockopt net/socket.c:2391 [inline] __se_sys_getsockopt net/socket.c:2388 [inline] __x64_sys_getsockopt+0x2a1/0x370 net/socket.c:2388 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: 0033:0x7f510658045a Code: ff c3 66 0f 1f 44 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb b8 0f 1f 44 00 00 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 a8 ff ff ff f7 RSP: 002b:00007ffdb6b9f538 EFLAGS: 00000242 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 00007ffdb6b9f560 RCX: 00007f510658045a RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00007ffdb6b9f55c R09: 0079746972756365 R10: 00007ffdb6b9f560 R11: 0000000000000242 R12: 00007f5106708a00 R13: 00007ffdb6b9f55c R14: 0000000000000000 R15: 00007f5106709e40