============================================ WARNING: possible recursive locking detected 6.9.0-syzkaller-09868-g6e51b4b5bbc0 #0 Not tainted -------------------------------------------- syz-fuzzer/5189 is trying to acquire lock: ffff888025ace1d8 (&qs->lock){-.-.}-{2:2}, at: queue_stack_map_push_elem+0x353/0x420 kernel/bpf/queue_stack_maps.c:210 but task is already holding lock: ffff88801e2c61d8 (&qs->lock){-.-.}-{2:2}, at: queue_stack_map_push_elem+0x353/0x420 kernel/bpf/queue_stack_maps.c:210 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&qs->lock); lock(&qs->lock); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by syz-fuzzer/5189: #0: ffff88802624f868 (&pipe->mutex){+.+.}-{3:3}, at: pipe_read+0x141/0x1400 fs/pipe.c:264 #1: ffffffff8dbb1760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #1: ffffffff8dbb1760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #1: ffffffff8dbb1760 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #1: ffffffff8dbb1760 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2444 #2: ffff88801e2c61d8 (&qs->lock){-.-.}-{2:2}, at: queue_stack_map_push_elem+0x353/0x420 kernel/bpf/queue_stack_maps.c:210 #3: ffffffff8dbb1760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #3: ffffffff8dbb1760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #3: ffffffff8dbb1760 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #3: ffffffff8dbb1760 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2444 stack backtrace: CPU: 2 PID: 5189 Comm: syz-fuzzer Not tainted 6.9.0-syzkaller-09868-g6e51b4b5bbc0 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain kernel/locking/lockdep.c:3856 [inline] __lock_acquire+0x20e6/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 queue_stack_map_push_elem+0x353/0x420 kernel/bpf/queue_stack_maps.c:210 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:2012 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2253 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+0x231/0x590 kernel/trace/bpf_trace.c:2444 __bpf_trace_contention_end+0xca/0x110 include/trace/events/lock.h:122 __traceiter_contention_end+0x5a/0xa0 include/trace/events/lock.h:122 trace_contention_end.constprop.0+0xea/0x170 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x28e/0xcc0 kernel/locking/qspinlock.c:557 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+0x210/0x2c0 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0x42/0x60 kernel/locking/spinlock.c:162 queue_stack_map_push_elem+0x353/0x420 kernel/bpf/queue_stack_maps.c:210 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:2012 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2253 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+0x231/0x590 kernel/trace/bpf_trace.c:2444 __bpf_trace_contention_end+0xca/0x110 include/trace/events/lock.h:122 __traceiter_contention_end+0x5a/0xa0 include/trace/events/lock.h:122 trace_contention_end+0xce/0x140 include/trace/events/lock.h:122 __mutex_lock_common kernel/locking/mutex.c:617 [inline] __mutex_lock+0x19c/0x9c0 kernel/locking/mutex.c:752 pipe_read+0x141/0x1400 fs/pipe.c:264 call_read_iter include/linux/fs.h:2114 [inline] new_sync_read fs/read_write.c:395 [inline] vfs_read+0x9fd/0xb80 fs/read_write.c:476 ksys_read+0x1f8/0x260 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f 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:000000c000051d80 EFLAGS: 00000216 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000000000000001b RCX: 000000000040720e RDX: 0000000000010000 RSI: 000000c000840000 RDI: 000000000000001b RBP: 000000c000051dc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000216 R12: 000000c000051f00 R13: 000000000000000a R14: 000000c00082c1a0 R15: 0000000000000009