============================================ WARNING: possible recursive locking detected 6.9.0-rc7-syzkaller-01795-g383eed2de529 #0 Not tainted -------------------------------------------- kworker/u8:3/50 is trying to acquire lock: ffff88802af45020 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88802af45020 (&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: ffff8880229d2820 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff8880229d2820 (&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 7 locks held by kworker/u8:3/50: #0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3242 [inline] #0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3348 #1: ffffc90000ba7d00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3243 [inline] #1: ffffc90000ba7d00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3348 #2: ffffffff8e33a238 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #2: ffffffff8e33a238 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x463/0x820 kernel/rcu/tree_exp.h:939 #3: ffffffff8e33a1f0 (rcu_state.exp_mutex.wait_lock){+.+.}-{2:2}, at: __mutex_lock_common kernel/locking/mutex.c:706 [inline] #3: ffffffff8e33a1f0 (rcu_state.exp_mutex.wait_lock){+.+.}-{2:2}, at: __mutex_lock+0x7fc/0xd70 kernel/locking/mutex.c:752 #4: ffffffff8e334ea0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #4: ffffffff8e334ea0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #4: ffffffff8e334ea0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2391 [inline] #4: ffffffff8e334ea0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2433 #5: ffff8880229d2820 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #5: ffff8880229d2820 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:957 #6: ffffffff8e334ea0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #6: ffffffff8e334ea0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #6: ffffffff8e334ea0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2391 [inline] #6: ffffffff8e334ea0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2433 stack backtrace: CPU: 1 PID: 50 Comm: kworker/u8:3 Not tainted 6.9.0-rc7-syzkaller-01795-g383eed2de529 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Workqueue: events_unbound bpf_map_free_deferred 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+0x15c1/0x58e0 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_05fc780d7a5f93f9+0x4a/0x4e 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:2392 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2433 __traceiter_contention_end+0x7b/0xb0 include/trace/events/lock.h:122 trace_contention_end+0x114/0x140 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x939/0xc60 kernel/locking/qspinlock.c:560 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [inline] queued_spin_lock_slowpath+0x42/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x272/0x370 kernel/locking/spinlock_debug.c:116 spin_lock_bh include/linux/spinlock.h:356 [inline] sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:957 bpf_prog_05fc780d7a5f93f9+0x4a/0x4e 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:2392 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2433 __traceiter_contention_end+0x7b/0xb0 include/trace/events/lock.h:122 trace_contention_end+0xf5/0x120 include/trace/events/lock.h:122 __mutex_lock_common kernel/locking/mutex.c:727 [inline] __mutex_lock+0x991/0xd70 kernel/locking/mutex.c:752 exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] synchronize_rcu_expedited+0x463/0x820 kernel/rcu/tree_exp.h:939 synchronize_rcu+0x136/0x3e0 kernel/rcu/tree.c:3611 sock_hash_free+0xac/0x820 net/core/sock_map.c:1162 bpf_map_free_deferred+0xe6/0x110 kernel/bpf/syscall.c:746 process_one_work kernel/workqueue.c:3267 [inline] process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3348 worker_thread+0x86d/0xd70 kernel/workqueue.c:3429 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244