====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc3-next-20240409-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/14846 is trying to acquire lock: ffff88802ef13bf0 (clock-AF_INET6){++--}-{2:2}, at: sock_map_del_link net/core/sock_map.c:163 [inline] ffff88802ef13bf0 (clock-AF_INET6){++--}-{2:2}, at: sock_map_unref+0x442/0x5e0 net/core/sock_map.c:180 but task is already holding lock: ffff888051378a88 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888051378a88 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_update_common+0x20c/0xa30 net/core/sock_map.c:1013 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 bpf_prog_0ad30bd092d3b9fd+0x2/0x23 bpf_dispatcher_nop_func include/linux/bpf.h:1233 [inline] __bpf_prog_run include/linux/filter.h:688 [inline] bpf_prog_run include/linux/filter.h:695 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2392 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2433 __traceiter_kfree+0x2b/0x50 include/trace/events/kmem.h:94 trace_kfree include/trace/events/kmem.h:94 [inline] kfree+0x2ad/0x350 mm/slub.c:4501 rds_send_remove_from_sock+0x66e/0x800 net/rds/send.c:666 rds_send_path_drop_acked+0x36b/0x3b0 net/rds/send.c:709 rds_tcp_write_space+0x196/0x5f0 net/rds/tcp_send.c:199 tcp_new_space net/ipv4/tcp_input.c:5622 [inline] tcp_check_space+0x65e/0xb00 net/ipv4/tcp_input.c:5641 tcp_data_snd_check net/ipv4/tcp_input.c:5650 [inline] tcp_rcv_established+0x111d/0x2020 net/ipv4/tcp_input.c:6077 tcp_v6_do_rcv+0xa09/0x1300 net/ipv6/tcp_ipv6.c:1645 sk_backlog_rcv include/net/sock.h:1106 [inline] __release_sock+0x1c8/0x350 net/core/sock.c:2983 release_sock+0x61/0x1f0 net/core/sock.c:3549 rds_send_xmit+0x1d3d/0x25b0 net/rds/send.c:421 rds_send_worker+0x7d/0x2b0 net/rds/threads.c:200 process_one_work kernel/workqueue.c:3218 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299 worker_thread+0x86d/0xd70 kernel/workqueue.c:3380 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 -> #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 sock_map_del_link net/core/sock_map.c:163 [inline] sock_map_unref+0x442/0x5e0 net/core/sock_map.c:180 sock_hash_update_common+0x915/0xa30 net/core/sock_map.c:1036 sock_map_update_elem_sys+0x5a4/0x910 net/core/sock_map.c:584 map_update_elem+0x53a/0x6f0 kernel/bpf/syscall.c:1641 __sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5648 __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_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x72/0x7a 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 *** 3 locks held by syz-executor.3/14846: #0: ffff88805c583a58 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1671 [inline] #0: ffff88805c583a58 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_sk_acquire net/core/sock_map.c:117 [inline] #0: ffff88805c583a58 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_update_elem_sys+0x1cc/0x910 net/core/sock_map.c:578 #1: ffffffff8e335920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #1: ffffffff8e335920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #1: ffffffff8e335920 (rcu_read_lock){....}-{1:2}, at: sock_map_sk_acquire net/core/sock_map.c:118 [inline] #1: ffffffff8e335920 (rcu_read_lock){....}-{1:2}, at: sock_map_update_elem_sys+0x1d8/0x910 net/core/sock_map.c:578 #2: ffff888051378a88 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #2: ffff888051378a88 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_update_common+0x20c/0xa30 net/core/sock_map.c:1013 stack backtrace: CPU: 1 PID: 14846 Comm: syz-executor.3 Not tainted 6.9.0-rc3-next-20240409-syzkaller #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 sock_map_del_link net/core/sock_map.c:163 [inline] sock_map_unref+0x442/0x5e0 net/core/sock_map.c:180 sock_hash_update_common+0x915/0xa30 net/core/sock_map.c:1036 sock_map_update_elem_sys+0x5a4/0x910 net/core/sock_map.c:584 map_update_elem+0x53a/0x6f0 kernel/bpf/syscall.c:1641 __sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5648 __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_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x72/0x7a RIP: 0033:0x7f3bb3c7de69 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:00007f3bb37ff0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f3bb3dabf80 RCX: 00007f3bb3c7de69 RDX: 0000000000000020 RSI: 0000000020000340 RDI: 0000000000000002 RBP: 00007f3bb3cca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f3bb3dabf80 R15: 00007ffe7ae2fe68