====================================================== WARNING: possible circular locking dependency detected 5.15.152-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/5979 is trying to acquire lock: ffff888059f151c0 (&stab->lock){+.-.}-{2:2}, at: __sock_map_delete net/core/sock_map.c:416 [inline] ffff888059f151c0 (&stab->lock){+.-.}-{2:2}, at: sock_map_delete_elem+0x97/0x130 net/core/sock_map.c:448 but task is already holding lock: ffff88805d3fc290 (&psock->link_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline] ffff88805d3fc290 (&psock->link_lock){+...}-{2:2}, at: sock_map_del_link net/core/sock_map.c:147 [inline] ffff88805d3fc290 (&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_map_update_common+0x31c/0x5b0 net/core/sock_map.c:502 sock_map_update_elem_sys+0x440/0x770 net/core/sock_map.c:585 map_update_elem+0x6a0/0x7c0 kernel/bpf/syscall.c:1163 __sys_bpf+0x2fd/0x670 kernel/bpf/syscall.c:4617 __do_sys_bpf kernel/bpf/syscall.c:4733 [inline] __se_sys_bpf kernel/bpf/syscall.c:4731 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4731 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb -> #0 (&stab->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_map_delete net/core/sock_map.c:416 [inline] sock_map_delete_elem+0x97/0x130 net/core/sock_map.c:448 bpf_prog_330576d32f01b34b+0x5b/0x6e0 bpf_dispatcher_nop_func include/linux/bpf.h:780 [inline] __bpf_prog_run include/linux/filter.h:625 [inline] bpf_prog_run include/linux/filter.h:632 [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_update_common+0x911/0xa30 net/core/sock_map.c:1028 sock_map_update_elem_sys+0x485/0x770 net/core/sock_map.c:587 map_update_elem+0x6a0/0x7c0 kernel/bpf/syscall.c:1163 __sys_bpf+0x2fd/0x670 kernel/bpf/syscall.c:4617 __do_sys_bpf kernel/bpf/syscall.c:4733 [inline] __se_sys_bpf kernel/bpf/syscall.c:4731 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4731 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&psock->link_lock); lock(&stab->lock); lock(&psock->link_lock); lock(&stab->lock); *** DEADLOCK *** 5 locks held by syz-executor.4/5979: #0: ffff88807b1c6120 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1668 [inline] #0: ffff88807b1c6120 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_sk_acquire net/core/sock_map.c:119 [inline] #0: ffff88807b1c6120 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_update_elem_sys+0x1c8/0x770 net/core/sock_map.c:581 #1: ffffffff8c91f720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:268 #2: ffff88805afc9c20 (&htab->buckets[i].lock){+...}-{2:2}, at: sock_hash_update_common+0x20c/0xa30 net/core/sock_map.c:1005 #3: ffff88805d3fc290 (&psock->link_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline] #3: ffff88805d3fc290 (&psock->link_lock){+...}-{2:2}, at: sock_map_del_link net/core/sock_map.c:147 [inline] #3: ffff88805d3fc290 (&psock->link_lock){+...}-{2:2}, at: sock_map_unref+0xcc/0x5d0 net/core/sock_map.c:182 #4: ffffffff8c91f720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:268 stack backtrace: CPU: 1 PID: 5979 Comm: syz-executor.4 Not tainted 5.15.152-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb 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_map_delete net/core/sock_map.c:416 [inline] sock_map_delete_elem+0x97/0x130 net/core/sock_map.c:448 bpf_prog_330576d32f01b34b+0x5b/0x6e0 bpf_dispatcher_nop_func include/linux/bpf.h:780 [inline] __bpf_prog_run include/linux/filter.h:625 [inline] bpf_prog_run include/linux/filter.h:632 [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_update_common+0x911/0xa30 net/core/sock_map.c:1028 sock_map_update_elem_sys+0x485/0x770 net/core/sock_map.c:587 map_update_elem+0x6a0/0x7c0 kernel/bpf/syscall.c:1163 __sys_bpf+0x2fd/0x670 kernel/bpf/syscall.c:4617 __do_sys_bpf kernel/bpf/syscall.c:4733 [inline] __se_sys_bpf kernel/bpf/syscall.c:4731 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4731 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f9c0cd51da9 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:00007f9c0b2d20c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f9c0ce7ff80 RCX: 00007f9c0cd51da9 RDX: 0000000000000020 RSI: 0000000020000040 RDI: 0000000000000002 RBP: 00007f9c0cd9e47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f9c0ce7ff80 R15: 00007ffd08342f38