============================================ WARNING: possible recursive locking detected 6.14.0-rc7-syzkaller-00196-g88d324e69ea9 #0 Not tainted -------------------------------------------- syz.2.294/6810 is trying to acquire lock: ffff888035867268 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0xb0/0x7e0 kernel/bpf/lpm_trie.c:470 but task is already holding lock: ffff888033ae9268 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0xb0/0x7e0 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.2.294/6810: #0: ffff888077823a58 (sk_lock-AF_TIPC){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1624 [inline] #0: ffff888077823a58 (sk_lock-AF_TIPC){+.+.}-{0:0}, at: tipc_sendstream net/tipc/socket.c:1545 [inline] #0: ffff888077823a58 (sk_lock-AF_TIPC){+.+.}-{0:0}, at: tipc_send_packet+0x5e/0xa0 net/tipc/socket.c:1652 #1: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #1: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2370 [inline] #1: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2412 #2: ffff888033ae9268 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0xb0/0x7e0 kernel/bpf/lpm_trie.c:470 #3: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #3: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2370 [inline] #3: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2412 stack backtrace: CPU: 0 UID: 0 PID: 6810 Comm: syz.2.294 Not tainted 6.14.0-rc7-syzkaller-00196-g88d324e69ea9 #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+0x116/0x1f0 lib/dump_stack.c:120 print_deadlock_bug+0x2e3/0x410 kernel/locking/lockdep.c:3039 check_deadlock kernel/locking/lockdep.c:3091 [inline] validate_chain kernel/locking/lockdep.c:3893 [inline] __lock_acquire+0x2117/0x3c40 kernel/locking/lockdep.c:5228 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 trie_delete_elem+0xb0/0x7e0 kernel/bpf/lpm_trie.c:470 bpf_prog_5186c38a4019a4cb+0x4b/0x4f bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:692 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline] bpf_trace_run2+0x34c/0x590 kernel/trace/bpf_trace.c:2412 __bpf_trace_contention_end+0xca/0x110 include/trace/events/lock.h:122 __do_trace_contention_end include/trace/events/lock.h:122 [inline] trace_contention_end.constprop.0+0xf0/0x170 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x27e/0xc90 kernel/locking/qspinlock.c:557 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:577 [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+0x210/0x2c0 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0x42/0x60 kernel/locking/spinlock.c:162 trie_delete_elem+0xb0/0x7e0 kernel/bpf/lpm_trie.c:470 bpf_prog_1bfaf16aa5934b8e+0x4e/0x52 bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:692 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline] bpf_trace_run2+0x34c/0x590 kernel/trace/bpf_trace.c:2412 __do_trace_kfree include/trace/events/kmem.h:94 [inline] trace_kfree include/trace/events/kmem.h:94 [inline] kfree+0x244/0x4d0 mm/slub.c:4744 tipc_dest_list_purge+0x138/0x1f0 net/tipc/name_table.c:1202 tipc_send_group_mcast net/tipc/socket.c:1178 [inline] __tipc_sendmsg+0x11ee/0x1990 net/tipc/socket.c:1438 __tipc_sendstream+0xe30/0x1190 net/tipc/socket.c:1573 tipc_sendstream net/tipc/socket.c:1546 [inline] tipc_send_packet+0x6c/0xa0 net/tipc/socket.c:1652 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:733 [inline] ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2573 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2627 __sys_sendmsg+0x16e/0x220 net/socket.c:2659 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f529698d169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5297796038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f5296ba5fa0 RCX: 00007f529698d169 RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000008 RBP: 00007f5296a0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5296ba5fa0 R15: 00007ffd8369c898