============================================ WARNING: possible recursive locking detected 6.13.0-rc5-syzkaller-00142-g8ce4f287524c #0 Not tainted -------------------------------------------- sshd/5825 is trying to acquire lock: ffffc90003f3d0d8 (&rb->spinlock){....}-{2:2}, at: __bpf_ringbuf_reserve+0x1ea/0x600 kernel/bpf/ringbuf.c:427 but task is already holding lock: ffffc90003f290d8 (&rb->spinlock){....}-{2:2}, at: __bpf_ringbuf_reserve+0x1ea/0x600 kernel/bpf/ringbuf.c:427 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&rb->spinlock); lock(&rb->spinlock); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by sshd/5825: #0: ffff888062fa6468 (&pipe->mutex){+.+.}-{4:4}, at: pipe_read+0x127/0x13e0 fs/pipe.c:264 #1: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #1: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2361 [inline] #1: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2403 #2: ffffc90003f290d8 (&rb->spinlock){....}-{2:2}, at: __bpf_ringbuf_reserve+0x1ea/0x600 kernel/bpf/ringbuf.c:427 #3: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #3: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2361 [inline] #3: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2403 stack backtrace: CPU: 1 UID: 0 PID: 5825 Comm: sshd Not tainted 6.13.0-rc5-syzkaller-00142-g8ce4f287524c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3037 check_deadlock kernel/locking/lockdep.c:3089 [inline] validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3891 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __bpf_ringbuf_reserve+0x1ea/0x600 kernel/bpf/ringbuf.c:427 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:478 [inline] bpf_ringbuf_reserve+0x5c/0x70 kernel/bpf/ringbuf.c:470 bpf_prog_0e153dac479590bf+0x35/0x70 bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2362 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2403 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0x11b/0x140 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x114/0xdb0 kernel/locking/qspinlock.c:402 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 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xe1/0x120 kernel/locking/spinlock.c:162 __bpf_ringbuf_reserve+0x1ea/0x600 kernel/bpf/ringbuf.c:427 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:478 [inline] bpf_ringbuf_reserve+0x5c/0x70 kernel/bpf/ringbuf.c:470 bpf_prog_0e153dac479590bf+0x35/0x70 bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2362 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2403 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0xf9/0x120 include/trace/events/lock.h:95 __mutex_lock_common kernel/locking/mutex.c:587 [inline] __mutex_lock+0x1bd/0xee0 kernel/locking/mutex.c:735 pipe_read+0x127/0x13e0 fs/pipe.c:264 new_sync_read fs/read_write.c:484 [inline] vfs_read+0x991/0xb70 fs/read_write.c:565 ksys_read+0x18f/0x2b0 fs/read_write.c:708 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: 0033:0x7f953fcd8b6a Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffe31f1a6e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f953fcd8b6a RDX: 0000000000004000 RSI: 00007ffe31f1a708 RDI: 0000000000000009 RBP: 0000562dc467b3c0 R08: 0000000000000000 R09: 0000000000000000 R10: 00007ffe31f1a708 R11: 0000000000000246 R12: 0000562dc46735a0 R13: 0000562db679c937 R14: 0000562db679f480 R15: 0000562dc46735a0