====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc6-syzkaller-00109-ge0863634bf9f #0 Not tainted ------------------------------------------------------ syz-executor.4/13177 is trying to acquire lock: ffff88802c5843f0 (clock-AF_INET6){++--}-{2:2}, at: sk_psock_drop+0x34/0x500 net/core/skmsg.c:837 but task is already holding lock: ffff88802ac43368 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88802ac43368 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:945 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:945 0xffffffffa0001e6b bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run2+0x204/0x420 kernel/trace/bpf_trace.c:2420 trace_kfree include/trace/events/kmem.h:94 [inline] kfree+0x2af/0x3a0 mm/slub.c:4377 nf_conntrack_free+0x2ee/0x390 net/netfilter/nf_conntrack_core.c:1690 nf_ct_put include/net/netfilter/nf_conntrack.h:186 [inline] nf_ct_gc_expired+0x280/0x4a0 net/netfilter/nf_conntrack_core.c:726 ____nf_conntrack_find net/netfilter/nf_conntrack_core.c:752 [inline] __nf_conntrack_find_get+0x230/0x670 net/netfilter/nf_conntrack_core.c:780 resolve_normal_ct net/netfilter/nf_conntrack_core.c:1832 [inline] nf_conntrack_in+0x77e/0x1880 net/netfilter/nf_conntrack_core.c:1996 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook+0x2c4/0x450 include/linux/netfilter.h:269 NF_HOOK include/linux/netfilter.h:312 [inline] ip6_xmit+0xed4/0x17f0 net/ipv6/ip6_output.c:358 inet6_csk_xmit+0x466/0x700 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x1eda/0x3b80 net/ipv4/tcp_output.c:1462 tcp_cleanup_rbuf net/ipv4/tcp.c:1503 [inline] tcp_read_sock+0x88a/0xb10 net/ipv4/tcp.c:1622 rds_tcp_read_sock net/rds/tcp_recv.c:277 [inline] rds_tcp_data_ready+0x364/0x8b0 net/rds/tcp_recv.c:327 tcp_data_queue+0x1e6d/0x6d90 net/ipv4/tcp_input.c:5223 tcp_rcv_established+0xfb7/0x2020 net/ipv4/tcp_input.c:6170 tcp_v6_do_rcv+0xa09/0x1300 net/ipv6/tcp_ipv6.c:1644 tcp_v6_rcv+0x2ab1/0x3380 net/ipv6/tcp_ipv6.c:1913 ip6_protocol_deliver_rcu+0xc76/0x1570 net/ipv6/ip6_input.c:438 ip6_input_finish+0x186/0x2d0 net/ipv6/ip6_input.c:483 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5544 [inline] __netif_receive_skb+0x1ea/0x650 net/core/dev.c:5658 process_backlog+0x39d/0x7a0 net/core/dev.c:5987 __napi_poll+0xcb/0x490 net/core/dev.c:6638 napi_poll net/core/dev.c:6707 [inline] net_rx_action+0x7bb/0x1090 net/core/dev.c:6822 __do_softirq+0x2c6/0x980 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:851 [inline] __dev_queue_xmit+0x1697/0x3ca0 net/core/dev.c:4368 neigh_output include/net/neighbour.h:542 [inline] ip6_finish_output2+0xff8/0x1670 net/ipv6/ip6_output.c:137 ip6_finish_output+0x41e/0x810 net/ipv6/ip6_output.c:222 NF_HOOK include/linux/netfilter.h:314 [inline] ip6_xmit+0xefe/0x17f0 net/ipv6/ip6_output.c:358 inet6_csk_xmit+0x466/0x700 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x1eda/0x3b80 net/ipv4/tcp_output.c:1462 tcp_transmit_skb net/ipv4/tcp_output.c:1480 [inline] tcp_write_xmit+0x1445/0x6100 net/ipv4/tcp_output.c:2792 tcp_sendmsg_locked+0x27be/0x4d00 net/ipv4/tcp.c:1290 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1342 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xef/0x270 net/socket.c:745 sock_sendmsg+0x134/0x200 net/socket.c:768 splice_to_socket+0xa13/0x10b0 fs/splice.c:889 do_splice_from fs/splice.c:941 [inline] direct_splice_actor+0x11e/0x220 fs/splice.c:1164 splice_direct_to_actor+0x58e/0xc90 fs/splice.c:1108 do_splice_direct_actor fs/splice.c:1207 [inline] do_splice_direct+0x28c/0x3e0 fs/splice.c:1233 do_sendfile+0x56d/0xdc0 fs/read_write.c:1295 __do_sys_sendfile64 fs/read_write.c:1362 [inline] __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1348 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 -> #0 (clock-AF_INET6){++--}-{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_write_lock_bh include/linux/rwlock_api_smp.h:202 [inline] _raw_write_lock_bh+0x35/0x50 kernel/locking/spinlock.c:334 sk_psock_drop+0x34/0x500 net/core/skmsg.c:837 sock_hash_delete_elem+0x392/0x400 net/core/sock_map.c:949 map_delete_elem+0x464/0x5e0 kernel/bpf/syscall.c:1696 __sys_bpf+0x598/0x810 kernel/bpf/syscall.c:5651 __do_sys_bpf kernel/bpf/syscall.c:5767 [inline] __se_sys_bpf kernel/bpf/syscall.c:5765 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5765 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(clock-AF_INET6); lock(&htab->buckets[i].lock); lock(clock-AF_INET6); *** DEADLOCK *** 2 locks held by syz-executor.4/13177: #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: map_delete_elem+0x388/0x5e0 kernel/bpf/syscall.c:1695 #1: ffff88802ac43368 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #1: ffff88802ac43368 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:945 stack backtrace: CPU: 0 PID: 13177 Comm: syz-executor.4 Not tainted 6.9.0-rc6-syzkaller-00109-ge0863634bf9f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __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_write_lock_bh include/linux/rwlock_api_smp.h:202 [inline] _raw_write_lock_bh+0x35/0x50 kernel/locking/spinlock.c:334 sk_psock_drop+0x34/0x500 net/core/skmsg.c:837 sock_hash_delete_elem+0x392/0x400 net/core/sock_map.c:949 map_delete_elem+0x464/0x5e0 kernel/bpf/syscall.c:1696 __sys_bpf+0x598/0x810 kernel/bpf/syscall.c:5651 __do_sys_bpf kernel/bpf/syscall.c:5767 [inline] __se_sys_bpf kernel/bpf/syscall.c:5765 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5765 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: 0033:0x7f98ec27dca9 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:00007f98ed0170c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f98ec3abf80 RCX: 00007f98ec27dca9 RDX: 0000000000000020 RSI: 00000000200015c0 RDI: 0000000000000003 RBP: 00007f98ec2c947e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f98ec3abf80 R15: 00007ffea2f743e8