============================================ WARNING: possible recursive locking detected 6.9.0-syzkaller-12123-g531876c80004 #0 Not tainted -------------------------------------------- syz-executor.0/6370 is trying to acquire lock: ffff888024f42260 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888024f42260 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:957 but task is already holding lock: ffff88801c74a620 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88801c74a620 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:957 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&htab->buckets[i].lock); lock(&htab->buckets[i].lock); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by syz-executor.0/6370: #0: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #0: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run10+0x330/0x680 kernel/trace/bpf_trace.c:2452 #1: ffff88801c74a620 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #1: ffff88801c74a620 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:957 #2: ffff88806bb6a2b0 (&psock->link_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #2: ffff88806bb6a2b0 (&psock->link_lock){+...}-{2:2}, at: sock_map_del_link net/core/sock_map.c:157 [inline] #2: ffff88806bb6a2b0 (&psock->link_lock){+...}-{2:2}, at: sock_map_unref+0xcc/0x5e0 net/core/sock_map.c:192 #3: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #3: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #3: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #3: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2444 stack backtrace: CPU: 1 PID: 6370 Comm: syz-executor.0 Not tainted 6.9.0-syzkaller-12123-g531876c80004 #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_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3856 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 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 bpf_prog_b89bc06253186eb1+0x56/0x5a 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+0x2bb/0x360 mm/slub.c:4544 sk_psock_free_link include/linux/skmsg.h:423 [inline] sock_map_del_link net/core/sock_map.c:170 [inline] sock_map_unref+0x3ac/0x5e0 net/core/sock_map.c:192 sock_hash_delete_elem+0x392/0x400 net/core/sock_map.c:961 bpf_prog_2c29ac5cdc6b1842+0x42/0x46 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_run10+0x420/0x680 kernel/trace/bpf_trace.c:2452 __bpf_trace_percpu_alloc_percpu+0x4e/0x70 include/trace/events/percpu.h:11 trace_percpu_alloc_percpu include/trace/events/percpu.h:11 [inline] pcpu_alloc_noprof+0x1519/0x16e0 mm/percpu.c:1904 bpf_prog_alloc_no_stats+0x10d/0x4b0 kernel/bpf/core.c:113 bpf_prog_alloc+0x3a/0x1b0 kernel/bpf/core.c:145 bpf_prog_load+0x7f7/0x20f0 kernel/bpf/syscall.c:2818 __sys_bpf+0x4ee/0x810 kernel/bpf/syscall.c:5709 __do_sys_bpf kernel/bpf/syscall.c:5816 [inline] __se_sys_bpf kernel/bpf/syscall.c:5814 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5814 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8b89c7cee9 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:00007f8b897ff0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f8b89db3fa0 RCX: 00007f8b89c7cee9 RDX: 0000000000000090 RSI: 0000000020000840 RDI: 0000000000000005 RBP: 00007f8b89cc947f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f8b89db3fa0 R15: 00007ffc64e52318