====================================================== WARNING: possible circular locking dependency detected 5.15.156-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.2/6694 is trying to acquire lock: ffff888079ea0bd8 (clock-AF_UNIX){+...}-{2:2}, at: sk_psock_drop+0x2f/0x3b0 net/core/skmsg.c:835 but task is already holding lock: ffff8880749e1e20 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0x177/0x400 net/core/sock_map.c:943 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+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_hash_delete_elem+0x177/0x400 net/core/sock_map.c:943 0xffffffffa00365ba bpf_dispatcher_nop_func include/linux/bpf.h:785 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run4+0x1ea/0x390 kernel/trace/bpf_trace.c:1919 __bpf_trace_mm_page_alloc+0xba/0xe0 include/trace/events/kmem.h:201 __traceiter_mm_page_alloc+0x35/0x50 include/trace/events/kmem.h:201 trace_mm_page_alloc include/trace/events/kmem.h:201 [inline] __alloc_pages+0x6e0/0x700 mm/page_alloc.c:5445 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xbb/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] kmem_cache_alloc_node_trace+0x1ce/0x2e0 mm/slub.c:3270 kmalloc_node include/linux/slab.h:609 [inline] kzalloc_node include/linux/slab.h:732 [inline] sk_psock_init+0x114/0x6b0 net/core/skmsg.c:712 sock_map_link+0x708/0xdb0 net/core/sock_map.c:277 sock_hash_update_common+0xd1/0xa30 net/core/sock_map.c:1001 sock_map_update_elem_sys+0x485/0x770 net/core/sock_map.c:590 map_update_elem+0x6a0/0x7c0 kernel/bpf/syscall.c:1185 __sys_bpf+0x2fd/0x670 kernel/bpf/syscall.c:4639 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline] __se_sys_bpf kernel/bpf/syscall.c:4753 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (clock-AF_UNIX){+...}-{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_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline] _raw_write_lock_bh+0x31/0x40 kernel/locking/spinlock.c:324 sk_psock_drop+0x2f/0x3b0 net/core/skmsg.c:835 sock_hash_delete_elem+0x388/0x400 net/core/sock_map.c:947 map_delete_elem+0x431/0x580 kernel/bpf/syscall.c:1239 __sys_bpf+0x311/0x670 kernel/bpf/syscall.c:4642 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline] __se_sys_bpf kernel/bpf/syscall.c:4753 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 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.2/6694: #0: ffffffff8c91fb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 #1: ffff8880749e1e20 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0x177/0x400 net/core/sock_map.c:943 stack backtrace: CPU: 0 PID: 6694 Comm: syz-executor.2 Not tainted 5.15.156-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+0x1e3/0x2d0 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_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline] _raw_write_lock_bh+0x31/0x40 kernel/locking/spinlock.c:324 sk_psock_drop+0x2f/0x3b0 net/core/skmsg.c:835 sock_hash_delete_elem+0x388/0x400 net/core/sock_map.c:947 map_delete_elem+0x431/0x580 kernel/bpf/syscall.c:1239 __sys_bpf+0x311/0x670 kernel/bpf/syscall.c:4642 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline] __se_sys_bpf kernel/bpf/syscall.c:4753 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f7e4e4b7ea9 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:00007f7e4ca2a0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f7e4e5e5f80 RCX: 00007f7e4e4b7ea9 RDX: 0000000000000020 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007f7e4e5044a4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f7e4e5e5f80 R15: 00007fffe9eb8388