syzbot

======================================================
WARNING: possible circular locking dependency detected
6.9.0-syzkaller-09429-g61307b7be41a #0 Not tainted
------------------------------------------------------
syz-executor.1/9190 is trying to acquire lock:
ffff88805fa16258 (&psock->ingress_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff88805fa16258 (&psock->ingress_lock){+...}-{2:2}, at: sk_psock_stop net/core/skmsg.c:802 [inline]
ffff88805fa16258 (&psock->ingress_lock){+...}-{2:2}, at: sk_psock_drop+0x2fb/0x500 net/core/skmsg.c:846

but task is already holding lock:
ffff888022f8e8f8 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff888022f8e8f8 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:957

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&htab->buckets[i].lock){+.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
       _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
       spin_lock_bh include/linux/spinlock.h:356 [inline]
       sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:957
       0xffffffffa0000893
       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+0x2ee/0x540 kernel/trace/bpf_trace.c:2444
       trace_kfree include/trace/events/kmem.h:94 [inline]
       kfree+0x2bb/0x360 mm/slub.c:4544
       sk_psock_cork_free include/linux/skmsg.h:432 [inline]
       sk_psock_stop+0xc5/0x110 net/core/skmsg.c:804
       sock_map_close+0x1b2/0x2d0 net/core/sock_map.c:1692
       inet_release+0x17f/0x200 net/ipv4/af_inet.c:437
       __sock_release net/socket.c:659 [inline]
       sock_close+0xbe/0x240 net/socket.c:1421
       __fput+0x42b/0x8a0 fs/file_table.c:422
       task_work_run+0x251/0x310 kernel/task_work.c:180
       exit_task_work include/linux/task_work.h:38 [inline]
       do_exit+0xa1b/0x27e0 kernel/exit.c:877
       do_group_exit+0x207/0x2c0 kernel/exit.c:1026
       get_signal+0x16a1/0x1740 kernel/signal.c:2911
       arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310
       exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
       exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
       __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
       syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
       do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&psock->ingress_lock){+...}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
       __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
       _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
       spin_lock_bh include/linux/spinlock.h:356 [inline]
       sk_psock_stop net/core/skmsg.c:802 [inline]
       sk_psock_drop+0x2fb/0x500 net/core/skmsg.c:846
       sock_hash_delete_elem+0x392/0x400 net/core/sock_map.c:961
       map_delete_elem+0x466/0x5e0 kernel/bpf/syscall.c:1709
       __sys_bpf+0x598/0x810 kernel/bpf/syscall.c:5678
       __do_sys_bpf kernel/bpf/syscall.c:5794 [inline]
       __se_sys_bpf kernel/bpf/syscall.c:5792 [inline]
       __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5792
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&htab->buckets[i].lock);
                               lock(&psock->ingress_lock);
                               lock(&htab->buckets[i].lock);
  lock(&psock->ingress_lock);

 *** DEADLOCK ***

2 locks held by syz-executor.1/9190:
 #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: map_delete_elem+0x388/0x5e0 kernel/bpf/syscall.c:1708
 #1: ffff888022f8e8f8 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
 #1: ffff888022f8e8f8 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:957

stack backtrace:
CPU: 0 PID: 9190 Comm: syz-executor.1 Not tainted 6.9.0-syzkaller-09429-g61307b7be41a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
 _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 sk_psock_stop net/core/skmsg.c:802 [inline]
 sk_psock_drop+0x2fb/0x500 net/core/skmsg.c:846
 sock_hash_delete_elem+0x392/0x400 net/core/sock_map.c:961
 map_delete_elem+0x466/0x5e0 kernel/bpf/syscall.c:1709
 __sys_bpf+0x598/0x810 kernel/bpf/syscall.c:5678
 __do_sys_bpf kernel/bpf/syscall.c:5794 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5792 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5792
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9f72c7cee9
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:00007f9f739740c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f9f72dabf80 RCX: 00007f9f72c7cee9
RDX: 0000000000000020 RSI: 0000000020000400 RDI: 0000000000000003
RBP: 00007f9f72cc949e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f9f72dabf80 R15: 00007ffd36e608d8
 </TASK>