============================================ WARNING: possible recursive locking detected 6.9.0-syzkaller-g7ee332c9f12b #0 Not tainted -------------------------------------------- syz-executor.0/5486 is trying to acquire lock: ffff88803c5ee220 (&stab->lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88803c5ee220 (&stab->lock){+.-.}-{2:2}, at: __sock_map_delete+0x43/0xe0 net/core/sock_map.c:429 but task is already holding lock: ffff88803c5eea20 (&stab->lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88803c5eea20 (&stab->lock){+.-.}-{2:2}, at: sock_map_update_common+0x197/0x870 net/core/sock_map.c:505 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&stab->lock); lock(&stab->lock); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by syz-executor.0/5486: #0: ffff88803bf24258 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1595 [inline] #0: ffff88803bf24258 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_sk_acquire net/core/sock_map.c:129 [inline] #0: ffff88803bf24258 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_update_elem_sys+0x1b6/0x570 net/core/sock_map.c:590 #1: ffffffff8dbb1ce0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #1: ffffffff8dbb1ce0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #1: ffffffff8dbb1ce0 (rcu_read_lock){....}-{1:2}, at: sock_map_sk_acquire net/core/sock_map.c:130 [inline] #1: ffffffff8dbb1ce0 (rcu_read_lock){....}-{1:2}, at: sock_map_update_elem_sys+0x1d8/0x570 net/core/sock_map.c:590 #2: ffff88803c5eea20 (&stab->lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #2: ffff88803c5eea20 (&stab->lock){+.-.}-{2:2}, at: sock_map_update_common+0x197/0x870 net/core/sock_map.c:505 #3: ffff88802da152b0 (&psock->link_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #3: ffff88802da152b0 (&psock->link_lock){+...}-{2:2}, at: sock_map_del_link net/core/sock_map.c:157 [inline] #3: ffff88802da152b0 (&psock->link_lock){+...}-{2:2}, at: sock_map_unref+0xbf/0x6e0 net/core/sock_map.c:192 #4: ffffffff8dbb1ce0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #4: ffffffff8dbb1ce0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #4: ffffffff8dbb1ce0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #4: ffffffff8dbb1ce0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2444 stack backtrace: CPU: 0 PID: 5486 Comm: syz-executor.0 Not tainted 6.9.0-syzkaller-g7ee332c9f12b #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain kernel/locking/lockdep.c:3856 [inline] __lock_acquire+0x20e6/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] __sock_map_delete+0x43/0xe0 net/core/sock_map.c:429 sock_map_delete_elem+0xb5/0x100 net/core/sock_map.c:461 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:2012 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2253 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+0x231/0x590 kernel/trace/bpf_trace.c:2444 trace_kfree include/trace/events/kmem.h:94 [inline] kfree+0x225/0x3a0 mm/slub.c:4450 sk_psock_free_link include/linux/skmsg.h:425 [inline] sock_map_del_link net/core/sock_map.c:170 [inline] sock_map_unref+0x392/0x6e0 net/core/sock_map.c:192 sock_map_update_common+0x4f3/0x870 net/core/sock_map.c:518 sock_map_update_elem_sys+0x3bb/0x570 net/core/sock_map.c:594 bpf_map_update_value+0x36c/0x6c0 kernel/bpf/syscall.c:172 map_update_elem+0x623/0x910 kernel/bpf/syscall.c:1654 __sys_bpf+0xac0/0x4b70 kernel/bpf/syscall.c:5675 __do_sys_bpf kernel/bpf/syscall.c:5794 [inline] __se_sys_bpf kernel/bpf/syscall.c:5792 [inline] __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5792 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdabac7dea9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fdabba0d0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fdabadabf80 RCX: 00007fdabac7dea9 RDX: 0000000000000020 RSI: 0000000020000680 RDI: 0000000000000002 RBP: 00007fdabacca4a4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fdabadabf80 R15: 00007ffda6ad4b38