====================================================== WARNING: possible circular locking dependency detected 5.15.160-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/5079 is trying to acquire lock: ffff8880794ec290 (&psock->link_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline] ffff8880794ec290 (&psock->link_lock){+...}-{2:2}, at: sock_map_add_link net/core/sock_map.c:136 [inline] ffff8880794ec290 (&psock->link_lock){+...}-{2:2}, at: sock_map_update_common+0x31c/0x5b0 net/core/sock_map.c:505 but task is already holding lock: ffff88807823c9c0 (&stab->lock){+.-.}-{2:2}, at: sock_map_update_common+0x1b6/0x5b0 net/core/sock_map.c:495 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 0xffffffffa0028c7b 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:421 [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 -> #0 (&psock->link_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] sock_map_add_link net/core/sock_map.c:136 [inline] sock_map_update_common+0x31c/0x5b0 net/core/sock_map.c:505 sock_map_update_elem_sys+0x440/0x770 net/core/sock_map.c:588 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 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&stab->lock); lock(&psock->link_lock); lock(&stab->lock); lock(&psock->link_lock); *** DEADLOCK *** 3 locks held by syz-executor.3/5079: #0: ffff888019ca3120 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1668 [inline] #0: ffff888019ca3120 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_sk_acquire net/core/sock_map.c:119 [inline] #0: ffff888019ca3120 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_update_elem_sys+0x1c8/0x770 net/core/sock_map.c:584 #1: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 #2: ffff88807823c9c0 (&stab->lock){+.-.}-{2:2}, at: sock_map_update_common+0x1b6/0x5b0 net/core/sock_map.c:495 stack backtrace: CPU: 1 PID: 5079 Comm: syz-executor.3 Not tainted 5.15.160-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: __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] sock_map_add_link net/core/sock_map.c:136 [inline] sock_map_update_common+0x31c/0x5b0 net/core/sock_map.c:505 sock_map_update_elem_sys+0x440/0x770 net/core/sock_map.c:588 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 RIP: 0033:0x7f15915acea9 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:00007f15901050c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f15916e4050 RCX: 00007f15915acea9 RDX: 0000000000000020 RSI: 00000000200000c0 RDI: 0000000000000002 RBP: 00007f159161bff4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f15916e4050 R15: 00007ffeac093cc8