======================================================
WARNING: possible circular locking dependency detected
5.15.157-syzkaller #0 Not tainted
------------------------------------------------------
kworker/1:22/7882 is trying to acquire lock:
ffff888061350668 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0x177/0x400 net/core/sock_map.c:943

but task is already holding lock:
ffff88801ea43290 (&psock->link_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline]
ffff88801ea43290 (&psock->link_lock){+...}-{2:2}, at: sock_map_del_link net/core/sock_map.c:147 [inline]
ffff88801ea43290 (&psock->link_lock){+...}-{2:2}, at: sock_map_unref+0xcc/0x5d0 net/core/sock_map.c:182

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&psock->link_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
       spin_lock_bh include/linux/spinlock.h:368 [inline]
       sock_map_add_link net/core/sock_map.c:136 [inline]
       sock_hash_update_common+0x620/0xa30 net/core/sock_map.c:1027
       sock_map_update_elem_sys+0x485/0x770 net/core/sock_map.c:590
       map_update_elem+0x6a0/0x7c0 kernel/bpf/syscall.c:1185
       __sys_bpf+0x2fd/0x670 kernel/bpf/syscall.c:4639
       __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

-> #0 (&htab->buckets[i].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
       sock_hash_delete_elem+0x177/0x400 net/core/sock_map.c:943
       bpf_prog_bc4ba9860fbb0da4+0x3e/0x100
       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_run2+0x19e/0x340 kernel/trace/bpf_trace.c:1917
       __bpf_trace_kfree+0x6e/0x90 include/trace/events/kmem.h:118
       trace_kfree include/trace/events/kmem.h:118 [inline]
       kfree+0x22f/0x270 mm/slub.c:4549
       sk_psock_free_link include/linux/skmsg.h:422 [inline]
       sock_map_del_link net/core/sock_map.c:160 [inline]
       sock_map_unref+0x3ac/0x5d0 net/core/sock_map.c:182
       sock_hash_free+0x4d5/0x780 net/core/sock_map.c:1174
       process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
       worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
       kthread+0x3f6/0x4f0 kernel/kthread.c:334
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300

other info that might help us debug this:

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

6 locks held by kworker/1:22/7882:
 #0: ffff888011c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc900034c7d20 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffff8880267f0120 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1668 [inline]
 #2: ffff8880267f0120 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_hash_free+0x443/0x780 net/core/sock_map.c:1172
 #3: ffffffff8c91fb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311
 #4: ffff88801ea43290 (&psock->link_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline]
 #4: ffff88801ea43290 (&psock->link_lock){+...}-{2:2}, at: sock_map_del_link net/core/sock_map.c:147 [inline]
 #4: ffff88801ea43290 (&psock->link_lock){+...}-{2:2}, at: sock_map_unref+0xcc/0x5d0 net/core/sock_map.c:182
 #5: ffffffff8c91fb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311

stack backtrace:
CPU: 1 PID: 7882 Comm: kworker/1:22 Not tainted 5.15.157-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events bpf_map_free_deferred
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
 sock_hash_delete_elem+0x177/0x400 net/core/sock_map.c:943
 bpf_prog_bc4ba9860fbb0da4+0x3e/0x100
 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_run2+0x19e/0x340 kernel/trace/bpf_trace.c:1917
 __bpf_trace_kfree+0x6e/0x90 include/trace/events/kmem.h:118
 trace_kfree include/trace/events/kmem.h:118 [inline]
 kfree+0x22f/0x270 mm/slub.c:4549
 sk_psock_free_link include/linux/skmsg.h:422 [inline]
 sock_map_del_link net/core/sock_map.c:160 [inline]
 sock_map_unref+0x3ac/0x5d0 net/core/sock_map.c:182
 sock_hash_free+0x4d5/0x780 net/core/sock_map.c:1174
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300
 </TASK>