============================================ WARNING: possible recursive locking detected 6.9.0-rc5-syzkaller-00355-g2c8159388952 #0 Not tainted -------------------------------------------- syz-execprog/5408 is trying to acquire lock: ffff88806151d200 (&stab->lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88806151d200 (&stab->lock){+.-.}-{2:2}, at: __sock_map_delete net/core/sock_map.c:417 [inline] ffff88806151d200 (&stab->lock){+.-.}-{2:2}, at: sock_map_delete_elem+0x171/0x250 net/core/sock_map.c:449 but task is already holding lock: ffff88806151ba00 (&stab->lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88806151ba00 (&stab->lock){+.-.}-{2:2}, at: __sock_map_delete net/core/sock_map.c:417 [inline] ffff88806151ba00 (&stab->lock){+.-.}-{2:2}, at: sock_map_delete_elem+0x171/0x250 net/core/sock_map.c:449 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&stab->lock); lock(&stab->lock); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by syz-execprog/5408: #0: ffff888017fe6868 (&pipe->mutex){+.+.}-{3:3}, at: pipe_read+0x126/0x13e0 fs/pipe.c:264 #1: ffffffff8dd32120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #1: ffffffff8dd32120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #1: ffffffff8dd32120 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] #1: ffffffff8dd32120 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x110/0x420 kernel/trace/bpf_trace.c:2420 #2: ffff88806151ba00 (&stab->lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #2: ffff88806151ba00 (&stab->lock){+.-.}-{2:2}, at: __sock_map_delete net/core/sock_map.c:417 [inline] #2: ffff88806151ba00 (&stab->lock){+.-.}-{2:2}, at: sock_map_delete_elem+0x171/0x250 net/core/sock_map.c:449 #3: ffffffff8dd32120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #3: ffffffff8dd32120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #3: ffffffff8dd32120 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] #3: ffffffff8dd32120 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x110/0x420 kernel/trace/bpf_trace.c:2420 stack backtrace: CPU: 0 PID: 5408 Comm: syz-execprog Not tainted 6.9.0-rc5-syzkaller-00355-g2c8159388952 #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+0x23d/0x360 lib/dump_stack.c:114 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain kernel/locking/lockdep.c:3856 [inline] __lock_acquire+0x6a95/0x7fa0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e9/0x540 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] __sock_map_delete net/core/sock_map.c:417 [inline] sock_map_delete_elem+0x171/0x250 net/core/sock_map.c:449 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e 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+0x200/0x420 kernel/trace/bpf_trace.c:2420 __traceiter_contention_end+0x77/0xb0 include/trace/events/lock.h:122 trace_contention_end+0x10a/0x130 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x935/0xc50 kernel/locking/qspinlock.c:560 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x298/0x3a0 kernel/locking/spinlock_debug.c:116 spin_lock_bh include/linux/spinlock.h:356 [inline] __sock_map_delete net/core/sock_map.c:417 [inline] sock_map_delete_elem+0x171/0x250 net/core/sock_map.c:449 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e 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+0x200/0x420 kernel/trace/bpf_trace.c:2420 __traceiter_contention_end+0x77/0xb0 include/trace/events/lock.h:122 trace_contention_end+0xeb/0x110 include/trace/events/lock.h:122 __mutex_lock_common kernel/locking/mutex.c:617 [inline] __mutex_lock+0x2e1/0xd60 kernel/locking/mutex.c:752 pipe_read+0x126/0x13e0 fs/pipe.c:264 call_read_iter include/linux/fs.h:2104 [inline] new_sync_read fs/read_write.c:395 [inline] vfs_read+0x93a/0xb30 fs/read_write.c:476 ksys_read+0x19c/0x2c0 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x84/0x190 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x40720e Code: 48 83 ec 38 e8 13 00 00 00 48 83 c4 38 5d c3 cc cc cc cc cc cc cc cc cc cc cc cc cc 49 89 f2 48 89 fa 48 89 ce 48 89 df 0f 05 <48> 3d 01 f0 ff ff 76 15 48 f7 d8 48 89 c1 48 c7 c0 ff ff ff ff 48 RSP: 002b:000000c001341928 EFLAGS: 00000206 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000028 RCX: 000000000040720e RDX: 000000000000000c RSI: 000000c0015c2810 RDI: 0000000000000028 RBP: 000000c001341968 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 000000c00132bdc8 R13: 000000c00005378c R14: 000000c0004469c0 R15: 0000000000000000