====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc5-syzkaller-00007-g4d2008430ce8 #0 Not tainted ------------------------------------------------------ syz-executor.3/8706 is trying to acquire lock: ffff88802dad8290 (&psock->link_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88802dad8290 (&psock->link_lock){+...}-{2:2}, at: sock_map_add_link net/core/sock_map.c:134 [inline] ffff88802dad8290 (&psock->link_lock){+...}-{2:2}, at: sock_hash_update_common+0x624/0xa30 net/core/sock_map.c:1029 but task is already holding lock: ffff888029bca8f8 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888029bca8f8 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_update_common+0x20c/0xa30 net/core/sock_map.c:1013 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:945 0xffffffffa0002001 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run2+0x204/0x420 kernel/trace/bpf_trace.c:2420 trace_kfree include/trace/events/kmem.h:94 [inline] kfree+0x2af/0x3a0 mm/slub.c:4377 sk_psock_free_link include/linux/skmsg.h:421 [inline] sock_map_del_link net/core/sock_map.c:158 [inline] sock_map_unref+0x3ac/0x5e0 net/core/sock_map.c:180 __sock_map_delete net/core/sock_map.c:423 [inline] sock_map_delete_elem+0x1a2/0x250 net/core/sock_map.c:449 bpf_prog_bf707b1a92d906a5+0xe/0x57 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run10+0x338/0x540 kernel/trace/bpf_trace.c:2428 __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+0x152e/0x16f0 mm/percpu.c:1878 mm_alloc_cid include/linux/mm_types.h:1175 [inline] mm_init+0x725/0xb60 kernel/fork.c:1301 bprm_mm_init fs/exec.c:374 [inline] alloc_bprm+0x2b1/0xa00 fs/exec.c:1580 kernel_execve+0x99/0xa10 fs/exec.c:2004 call_usermodehelper_exec_async+0x237/0x380 kernel/umh.c:110 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 (&psock->link_lock){+...}-{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_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_map_add_link net/core/sock_map.c:134 [inline] sock_hash_update_common+0x624/0xa30 net/core/sock_map.c:1029 sock_map_update_elem_sys+0x5a4/0x910 net/core/sock_map.c:584 map_update_elem+0x53a/0x6f0 kernel/bpf/syscall.c:1641 __sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5648 __do_sys_bpf kernel/bpf/syscall.c:5767 [inline] __se_sys_bpf kernel/bpf/syscall.c:5765 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5765 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(&psock->link_lock); lock(&htab->buckets[i].lock); lock(&psock->link_lock); *** DEADLOCK *** 3 locks held by syz-executor.3/8706: #0: ffff88807f755a58 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1671 [inline] #0: ffff88807f755a58 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_sk_acquire net/core/sock_map.c:117 [inline] #0: ffff88807f755a58 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_update_elem_sys+0x1cc/0x910 net/core/sock_map.c:578 #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: sock_map_sk_acquire net/core/sock_map.c:118 [inline] #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: sock_map_update_elem_sys+0x1d8/0x910 net/core/sock_map.c:578 #2: ffff888029bca8f8 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #2: ffff888029bca8f8 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_update_common+0x20c/0xa30 net/core/sock_map.c:1013 stack backtrace: CPU: 1 PID: 8706 Comm: syz-executor.3 Not tainted 6.9.0-rc5-syzkaller-00007-g4d2008430ce8 #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_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_map_add_link net/core/sock_map.c:134 [inline] sock_hash_update_common+0x624/0xa30 net/core/sock_map.c:1029 sock_map_update_elem_sys+0x5a4/0x910 net/core/sock_map.c:584 map_update_elem+0x53a/0x6f0 kernel/bpf/syscall.c:1641 __sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5648 __do_sys_bpf kernel/bpf/syscall.c:5767 [inline] __se_sys_bpf kernel/bpf/syscall.c:5765 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5765 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: 0033:0x7f40a347dea9 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:00007f40a42420c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f40a35abf80 RCX: 00007f40a347dea9 RDX: 0000000000000020 RSI: 00000000200003c0 RDI: 0000000000000002 RBP: 00007f40a34ca4a4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f40a35abf80 R15: 00007ffcb0d9efb8