syzbot

======================================================
WARNING: possible circular locking dependency detected
5.15.158-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.3/9953 is trying to acquire lock:
ffff88806339b238 (&psock->ingress_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline]
ffff88806339b238 (&psock->ingress_lock){+...}-{2:2}, at: sk_psock_stop+0x31/0x4c0 net/core/skmsg.c:802

but task is already holding lock:
ffff88801b7cf1c0 (&stab->lock){+.-.}-{2:2}, at: __sock_map_delete net/core/sock_map.c:419 [inline]
ffff88801b7cf1c0 (&stab->lock){+.-.}-{2:2}, at: sock_map_delete_elem+0x161/0x230 net/core/sock_map.c:451

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&stab->lock){+.-.}-{2:2}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
       _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178
       __sock_map_delete net/core/sock_map.c:419 [inline]
       sock_map_delete_elem+0x161/0x230 net/core/sock_map.c:451
       0xffffffffa002ce2e
       bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline]
       __bpf_prog_run include/linux/filter.h:628 [inline]
       bpf_prog_run include/linux/filter.h:635 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline]
       bpf_trace_run3+0x1d1/0x380 kernel/trace/bpf_trace.c:1918
       __bpf_trace_kmem_cache_free+0x99/0xc0 include/trace/events/kmem.h:138
       trace_kmem_cache_free include/trace/events/kmem.h:138 [inline]
       kmem_cache_free+0x1ce/0x1f0 mm/slub.c:3516
       __sk_msg_free+0x2cd/0x350 net/core/skmsg.c:205
       sk_msg_free net/core/skmsg.c:218 [inline]
       __sk_psock_purge_ingress_msg net/core/skmsg.c:769 [inline]
       __sk_psock_zap_ingress net/core/skmsg.c:787 [inline]
       sk_psock_stop+0x44c/0x4c0 net/core/skmsg.c:805
       sock_map_close+0x17c/0x290 net/core/sock_map.c:1578
       unix_release+0x7e/0xc0 net/unix/af_unix.c:949
       __sock_release net/socket.c:649 [inline]
       sock_close+0xcd/0x230 net/socket.c:1336
       __fput+0x3bf/0x890 fs/file_table.c:280
       task_work_run+0x129/0x1a0 kernel/task_work.c:164
       tracehook_notify_resume include/linux/tracehook.h:189 [inline]
       exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181
       exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
       __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
       syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
       do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (&psock->ingress_lock){+...}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
       __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
       _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178
       spin_lock_bh include/linux/spinlock.h:368 [inline]
       sk_psock_stop+0x31/0x4c0 net/core/skmsg.c:802
       sk_psock_drop+0x2aa/0x3b0 net/core/skmsg.c:844
       __sock_map_delete net/core/sock_map.c:425 [inline]
       sock_map_delete_elem+0x191/0x230 net/core/sock_map.c:451
       map_delete_elem+0x431/0x580 kernel/bpf/syscall.c:1239
       __sys_bpf+0x311/0x670 kernel/bpf/syscall.c:4642
       __do_sys_bpf kernel/bpf/syscall.c:4755 [inline]
       __se_sys_bpf kernel/bpf/syscall.c:4753 [inline]
       __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&stab->lock);
                               lock(&psock->ingress_lock);
                               lock(&stab->lock);
  lock(&psock->ingress_lock);

 *** DEADLOCK ***

2 locks held by syz-executor.3/9953:
 #0: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311
 #1: ffff88801b7cf1c0 (&stab->lock){+.-.}-{2:2}, at: __sock_map_delete net/core/sock_map.c:419 [inline]
 #1: ffff88801b7cf1c0 (&stab->lock){+.-.}-{2:2}, at: sock_map_delete_elem+0x161/0x230 net/core/sock_map.c:451

stack backtrace:
CPU: 1 PID: 9953 Comm: syz-executor.3 Not tainted 5.15.158-syzkaller #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+0x1e3/0x2d0 lib/dump_stack.c:106
 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:368 [inline]
 sk_psock_stop+0x31/0x4c0 net/core/skmsg.c:802
 sk_psock_drop+0x2aa/0x3b0 net/core/skmsg.c:844
 __sock_map_delete net/core/sock_map.c:425 [inline]
 sock_map_delete_elem+0x191/0x230 net/core/sock_map.c:451
 map_delete_elem+0x431/0x580 kernel/bpf/syscall.c:1239
 __sys_bpf+0x311/0x670 kernel/bpf/syscall.c:4642
 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4753 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fe6f2744ee9
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:00007fe6f0cb80c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fe6f2873f80 RCX: 00007fe6f2744ee9
RDX: 0000000000000020 RSI: 0000000020001cc0 RDI: 0000000000000003
RBP: 00007fe6f279149e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fe6f2873f80 R15: 00007fff26604128
 </TASK>