====================================================== WARNING: possible circular locking dependency detected 6.9.0-syzkaller-08561-g2c1713a8f1c9 #0 Not tainted ------------------------------------------------------ syz-executor.2/7657 is trying to acquire lock: ffff888048516bf0 (clock-AF_UNIX){++..}-{2:2}, at: sk_psock_drop+0x34/0x500 net/core/skmsg.c:837 but task is already holding lock: ffff888021c74c68 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888021c74c68 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:957 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:957 0xffffffffa0001cb6 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2444 trace_kfree include/trace/events/kmem.h:94 [inline] kfree+0x2bd/0x3b0 mm/slub.c:4450 __bpf_prog_put_noref+0xd7/0x310 kernel/bpf/syscall.c:2257 bpf_prog_put_deferred+0x2f3/0x3e0 kernel/bpf/syscall.c:2283 __bpf_prog_put kernel/bpf/syscall.c:2295 [inline] bpf_prog_put+0x264/0x2a0 kernel/bpf/syscall.c:2302 psock_set_prog include/linux/skmsg.h:481 [inline] sk_psock_stop_verdict net/core/skmsg.c:1248 [inline] sk_psock_drop+0x24d/0x500 net/core/skmsg.c:843 sk_psock_put include/linux/skmsg.h:463 [inline] sock_map_close+0x209/0x2d0 net/core/sock_map.c:1695 unix_release+0x85/0xc0 net/unix/af_unix.c:1048 __sock_release net/socket.c:659 [inline] sock_close+0xbc/0x240 net/socket.c:1421 __fput+0x429/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (clock-AF_UNIX){++..}-{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:961 map_delete_elem+0x464/0x5e0 kernel/bpf/syscall.c:1709 __sys_bpf+0x598/0x810 kernel/bpf/syscall.c:5678 __do_sys_bpf kernel/bpf/syscall.c:5794 [inline] __se_sys_bpf kernel/bpf/syscall.c:5792 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5792 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_UNIX); lock(&htab->buckets[i].lock); lock(clock-AF_UNIX); *** DEADLOCK *** 2 locks held by syz-executor.2/7657: #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: map_delete_elem+0x388/0x5e0 kernel/bpf/syscall.c:1708 #1: ffff888021c74c68 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #1: ffff888021c74c68 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:957 stack backtrace: CPU: 0 PID: 7657 Comm: syz-executor.2 Not tainted 6.9.0-syzkaller-08561-g2c1713a8f1c9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 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:961 map_delete_elem+0x464/0x5e0 kernel/bpf/syscall.c:1709 __sys_bpf+0x598/0x810 kernel/bpf/syscall.c:5678 __do_sys_bpf kernel/bpf/syscall.c:5794 [inline] __se_sys_bpf kernel/bpf/syscall.c:5792 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5792 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: 0033:0x7fdb1c07cee9 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:00007fdb1ce280c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fdb1c1abf80 RCX: 00007fdb1c07cee9 RDX: 0000000000000020 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007fdb1c0c949e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fdb1c1abf80 R15: 00007ffcefe71328