============================================ WARNING: possible recursive locking detected 6.10.0-syzkaller-12605-g8e0c0ec9b7dc #0 Not tainted -------------------------------------------- syz-executor316/5224 is trying to acquire lock: ffff888022d351f8 (&trie->lock){....}-{2:2}, at: trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:462 but task is already holding lock: ffff888022d349f8 (&trie->lock){....}-{2:2}, at: trie_update_elem+0xc8/0xc00 kernel/bpf/lpm_trie.c:333 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 3 locks held by syz-executor316/5224: #0: ffffffff8e737660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff8e737660 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e737660 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x3c4/0x540 kernel/bpf/syscall.c:202 #1: ffff888022d349f8 (&trie->lock){....}-{2:2}, at: trie_update_elem+0xc8/0xc00 kernel/bpf/lpm_trie.c:333 #2: ffffffff8e737660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #2: ffffffff8e737660 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8e737660 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2405 [inline] #2: ffffffff8e737660 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2447 stack backtrace: CPU: 1 UID: 0 PID: 5224 Comm: syz-executor316 Not tainted 6.10.0-syzkaller-12605-g8e0c0ec9b7dc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 check_deadlock kernel/locking/lockdep.c:3061 [inline] validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3855 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __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_029d1888f6cd2729+0x47/0x4b 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:2406 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2447 trace_kfree include/trace/events/kmem.h:94 [inline] kfree+0x2bb/0x360 mm/slub.c:4581 trie_update_elem+0x26c/0xc00 kernel/bpf/lpm_trie.c:436 bpf_map_update_value+0x4d3/0x540 kernel/bpf/syscall.c:203 generic_map_update_batch+0x60d/0x900 kernel/bpf/syscall.c:1889 bpf_map_do_batch+0x3e0/0x690 kernel/bpf/syscall.c:5218 __sys_bpf+0x377/0x810 __do_sys_bpf kernel/bpf/syscall.c:5817 [inline] __se_sys_bpf kernel/bpf/syscall.c:5815 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5815 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: 0033:0x7fbe536eaeb9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe3a2740d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbe536eaeb9 RDX: 0000000000000038 RSI: 0000000020000240 RDI: 000000000000001a RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000006 R10: 0000000000000006 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001