============================================ WARNING: possible recursive locking detected 6.9.0-syzkaller-12255-g0b32d436c015 #0 Not tainted -------------------------------------------- syz-fuzzer/5089 is trying to acquire lock: ffff8880239941d8 (&qs->lock){..-.}-{2:2}, at: __queue_map_get+0x14b/0x4d0 kernel/bpf/queue_stack_maps.c:105 but task is already holding lock: ffff8880629771d8 (&qs->lock){..-.}-{2:2}, at: __stack_map_get+0x14b/0x4b0 kernel/bpf/queue_stack_maps.c:140 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/5089: #0: ffff8880b943e798 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 #1: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #1: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #1: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #1: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x244/0x590 kernel/trace/bpf_trace.c:2446 #2: ffff8880629771d8 (&qs->lock){..-.}-{2:2}, at: __stack_map_get+0x14b/0x4b0 kernel/bpf/queue_stack_maps.c:140 #3: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #3: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #3: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #3: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2444 stack backtrace: CPU: 0 PID: 5089 Comm: syz-fuzzer Not tainted 6.9.0-syzkaller-12255-g0b32d436c015 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 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+0x15d3/0x5900 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_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __queue_map_get+0x14b/0x4d0 kernel/bpf/queue_stack_maps.c:105 bpf_prog_00798911c748094f+0x42/0x46 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+0x2ec/0x540 kernel/trace/bpf_trace.c:2444 trace_contention_end+0x114/0x140 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0xb81/0xdc0 kernel/locking/qspinlock.c:557 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 __stack_map_get+0x14b/0x4b0 kernel/bpf/queue_stack_maps.c:140 bpf_prog_00798911c748094f+0x42/0x46 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_run4+0x334/0x590 kernel/trace/bpf_trace.c:2446 __traceiter_sched_switch+0x98/0xd0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2535/0x49d0 kernel/sched/core.c:6742 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_hrtimeout_range_clock+0x2a9/0x480 kernel/time/hrtimer.c:2289 ep_poll fs/eventpoll.c:2062 [inline] do_epoll_wait+0x1d79/0x2040 fs/eventpoll.c:2464 do_epoll_pwait+0x56/0x1e0 fs/eventpoll.c:2498 __do_sys_epoll_pwait fs/eventpoll.c:2511 [inline] __se_sys_epoll_pwait fs/eventpoll.c:2505 [inline] __x64_sys_epoll_pwait+0x2b8/0x310 fs/eventpoll.c:2505 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: 0033:0x40720e 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:000000c00065f748 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000040720e RDX: 0000000000000080 RSI: 000000c00065f818 RDI: 0000000000000004 RBP: 000000c00065f790 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000329 R11: 0000000000000246 R12: 000000c00065f820 R13: 000000c00005678c R14: 000000c0003611e0 R15: 0000000000000000