====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc5-syzkaller-01452-ga9e7715ce8b3 #0 Not tainted ------------------------------------------------------ syz-executor.3/5449 is trying to acquire lock: ffff88807252e3f0 (clock-AF_UNIX){+...}-{2:2}, at: sk_psock_drop+0x34/0x500 net/core/skmsg.c:837 but task is already holding lock: ffff88807b83e420 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88807b83e420 (&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 0xffffffffa0001db6 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_run4+0x334/0x590 kernel/trace/bpf_trace.c:2446 trace_mm_page_alloc include/trace/events/kmem.h:177 [inline] __alloc_pages+0x694/0x6c0 mm/page_alloc.c:4597 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page+0x5f/0x160 mm/slub.c:2175 allocate_slab mm/slub.c:2338 [inline] new_slab+0x84/0x2f0 mm/slub.c:2391 ___slab_alloc+0xc73/0x1260 mm/slub.c:3525 __slab_alloc mm/slub.c:3610 [inline] __slab_alloc_node mm/slub.c:3663 [inline] slab_alloc_node mm/slub.c:3835 [inline] kmalloc_node_trace+0x264/0x3a0 mm/slub.c:4005 kmalloc_node include/linux/slab.h:644 [inline] kzalloc_node include/linux/slab.h:760 [inline] sk_psock_init+0x144/0x750 net/core/skmsg.c:717 sock_map_link+0x76b/0xe40 net/core/sock_map.c:287 sock_hash_update_common+0xd1/0xa30 net/core/sock_map.c:1015 sock_map_update_elem_sys+0x5a4/0x910 net/core/sock_map.c:596 map_update_elem+0x53a/0x6f0 kernel/bpf/syscall.c:1654 __sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5670 __do_sys_bpf kernel/bpf/syscall.c:5789 [inline] __se_sys_bpf kernel/bpf/syscall.c:5787 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5787 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_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:5673 __do_sys_bpf kernel/bpf/syscall.c:5789 [inline] __se_sys_bpf kernel/bpf/syscall.c:5787 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5787 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.3/5449: #0: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: map_delete_elem+0x388/0x5e0 kernel/bpf/syscall.c:1708 #1: ffff88807b83e420 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #1: ffff88807b83e420 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:957 stack backtrace: CPU: 0 PID: 5449 Comm: syz-executor.3 Not tainted 6.9.0-rc5-syzkaller-01452-ga9e7715ce8b3 #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:961 map_delete_elem+0x464/0x5e0 kernel/bpf/syscall.c:1709 __sys_bpf+0x598/0x810 kernel/bpf/syscall.c:5673 __do_sys_bpf kernel/bpf/syscall.c:5789 [inline] __se_sys_bpf kernel/bpf/syscall.c:5787 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5787 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: 0033:0x7f2e8227dca9 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:00007f2e830c40c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f2e823abf80 RCX: 00007f2e8227dca9 RDX: 0000000000000020 RSI: 0000000020000800 RDI: 0000000000000003 RBP: 00007f2e822c947e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f2e823abf80 R15: 00007ffc7024b478