====================================================== WARNING: possible circular locking dependency detected 6.1.91-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/8741 is trying to acquire lock: ffff888043807bb8 (clock-AF_UNIX){+...}-{2:2}, at: sk_psock_drop+0x30/0x500 net/core/skmsg.c:836 but task is already holding lock: ffff888078858a40 (&stab->lock){+.-.}-{2:2}, at: __sock_map_delete net/core/sock_map.c:419 [inline] ffff888078858a40 (&stab->lock){+.-.}-{2:2}, at: sock_map_delete_elem+0x161/0x230 net/core/sock_map.c:451 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&stab->lock){+.-.}-{2:2}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [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 0xffffffffa0000a70 bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline] bpf_trace_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2312 __bpf_trace_kfree+0x6e/0x90 include/trace/events/kmem.h:94 __traceiter_kfree+0x26/0x40 include/trace/events/kmem.h:94 trace_kfree include/trace/events/kmem.h:94 [inline] kfree+0xf6/0x190 mm/slab_common.c:994 __bpf_prog_put_noref+0x9c/0x2b0 kernel/bpf/syscall.c:2059 bpf_prog_put_deferred+0x2ee/0x3e0 kernel/bpf/syscall.c:2085 __bpf_prog_put kernel/bpf/syscall.c:2097 [inline] bpf_prog_put+0x260/0x2a0 kernel/bpf/syscall.c:2104 psock_set_prog include/linux/skmsg.h:472 [inline] sk_psock_stop_strp net/core/skmsg.c:1153 [inline] sk_psock_drop+0xd6/0x500 net/core/skmsg.c:840 sock_map_free+0x1e3/0x3d0 net/core/sock_map.c:353 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 -> #0 (clock-AF_UNIX){+...}-{2:2}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_write_lock_bh include/linux/rwlock_api_smp.h:202 [inline] _raw_write_lock_bh+0x31/0x40 kernel/locking/spinlock.c:334 sk_psock_drop+0x30/0x500 net/core/skmsg.c:836 __sock_map_delete net/core/sock_map.c:425 [inline] sock_map_delete_elem+0x191/0x230 net/core/sock_map.c:451 bpf_prog_107af3efe6330ca3+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline] __bpf_prog_run include/linux/filter.h:596 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline] bpf_trace_run10+0x475/0x520 kernel/trace/bpf_trace.c:2320 __bpf_trace_percpu_alloc_percpu+0x4a/0x60 include/trace/events/percpu.h:11 trace_percpu_alloc_percpu include/trace/events/percpu.h:11 [inline] pcpu_alloc+0x16d9/0x18f0 mm/percpu.c:1887 bpf_prog_alloc_no_stats+0xd5/0x3f0 kernel/bpf/core.c:101 bpf_prog_alloc+0x1c/0x1b0 kernel/bpf/core.c:130 bpf_prog_load+0x803/0x1bb0 kernel/bpf/syscall.c:2577 __sys_bpf+0x382/0x6c0 kernel/bpf/syscall.c:5005 __do_sys_bpf kernel/bpf/syscall.c:5109 [inline] __se_sys_bpf kernel/bpf/syscall.c:5107 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5107 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&stab->lock); lock(clock-AF_UNIX); lock(&stab->lock); lock(clock-AF_UNIX); *** DEADLOCK *** 2 locks held by syz-executor.3/8741: #0: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2272 [inline] #0: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run10+0x248/0x520 kernel/trace/bpf_trace.c:2320 #1: ffff888078858a40 (&stab->lock){+.-.}-{2:2}, at: __sock_map_delete net/core/sock_map.c:419 [inline] #1: ffff888078858a40 (&stab->lock){+.-.}-{2:2}, at: sock_map_delete_elem+0x161/0x230 net/core/sock_map.c:451 stack backtrace: CPU: 1 PID: 8741 Comm: syz-executor.3 Not tainted 6.1.91-syzkaller #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+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_write_lock_bh include/linux/rwlock_api_smp.h:202 [inline] _raw_write_lock_bh+0x31/0x40 kernel/locking/spinlock.c:334 sk_psock_drop+0x30/0x500 net/core/skmsg.c:836 __sock_map_delete net/core/sock_map.c:425 [inline] sock_map_delete_elem+0x191/0x230 net/core/sock_map.c:451 bpf_prog_107af3efe6330ca3+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline] __bpf_prog_run include/linux/filter.h:596 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline] bpf_trace_run10+0x475/0x520 kernel/trace/bpf_trace.c:2320 __bpf_trace_percpu_alloc_percpu+0x4a/0x60 include/trace/events/percpu.h:11 trace_percpu_alloc_percpu include/trace/events/percpu.h:11 [inline] pcpu_alloc+0x16d9/0x18f0 mm/percpu.c:1887 bpf_prog_alloc_no_stats+0xd5/0x3f0 kernel/bpf/core.c:101 bpf_prog_alloc+0x1c/0x1b0 kernel/bpf/core.c:130 bpf_prog_load+0x803/0x1bb0 kernel/bpf/syscall.c:2577 __sys_bpf+0x382/0x6c0 kernel/bpf/syscall.c:5005 __do_sys_bpf kernel/bpf/syscall.c:5109 [inline] __se_sys_bpf kernel/bpf/syscall.c:5107 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5107 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7efefc47cee9 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:00007efefd1490c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007efefc5abf80 RCX: 00007efefc47cee9 RDX: 0000000000000090 RSI: 00000000200000c0 RDI: 0000000000000005 RBP: 00007efefc4c949e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007efefc5abf80 R15: 00007fff76343f88