syzbot

============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
udevd/3637 is trying to acquire lock:
ffff88807dac7a18 (&qs->lock){-.-.}-{2:2}, at: __stack_map_get+0x11a/0x440 kernel/bpf/queue_stack_maps.c:144

but task is already holding lock:
ffff88807dac0218 (&qs->lock){-.-.}-{2:2}, at: __stack_map_get+0x11a/0x440 kernel/bpf/queue_stack_maps.c:144

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 udevd/3637:
 #0: ffff888078b3c0e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
 #1: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #1: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #1: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline]
 #1: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xda/0x3b0 kernel/trace/bpf_trace.c:2324
 #2: ffff88807dac0218 (&qs->lock){-.-.}-{2:2}, at: __stack_map_get+0x11a/0x440 kernel/bpf/queue_stack_maps.c:144
 #3: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #3: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #3: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline]
 #3: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xda/0x3b0 kernel/trace/bpf_trace.c:2324

stack backtrace:
CPU: 0 PID: 3637 Comm: udevd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 __lock_acquire+0x122f/0x7c50 kernel/locking/lockdep.c:-1
 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
 __stack_map_get+0x11a/0x440 kernel/bpf/queue_stack_maps.c:144
 bpf_prog_00798911c748094f+0x3a/0x3e
 bpf_dispatcher_nop_func include/linux/bpf.h:1012 [inline]
 __bpf_prog_run include/linux/filter.h:603 [inline]
 bpf_prog_run include/linux/filter.h:610 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2285 [inline]
 bpf_trace_run2+0x1cd/0x3b0 kernel/trace/bpf_trace.c:2324
 __traceiter_contention_end+0x74/0xa0 include/trace/events/lock.h:122
 trace_contention_end+0x13f/0x190 include/trace/events/lock.h:122
 __pv_queued_spin_lock_slowpath+0x7e8/0x9c0 kernel/locking/qspinlock.c:560
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline]
 queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock+0x217/0x280 kernel/locking/spinlock_debug.c:115
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0xb0/0xf0 kernel/locking/spinlock.c:162
 __stack_map_get+0x11a/0x440 kernel/bpf/queue_stack_maps.c:144
 bpf_prog_00798911c748094f+0x3a/0x3e
 bpf_dispatcher_nop_func include/linux/bpf.h:1012 [inline]
 __bpf_prog_run include/linux/filter.h:603 [inline]
 bpf_prog_run include/linux/filter.h:610 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2285 [inline]
 bpf_trace_run2+0x1cd/0x3b0 kernel/trace/bpf_trace.c:2324
 __traceiter_contention_end+0x74/0xa0 include/trace/events/lock.h:122
 trace_contention_end+0x123/0x170 include/trace/events/lock.h:122
 __mutex_lock_common kernel/locking/mutex.c:612 [inline]
 __mutex_lock+0x194/0xaf0 kernel/locking/mutex.c:747
 __fdget_pos+0x2ae/0x360 fs/file.c:1038
 fdget_pos include/linux/file.h:74 [inline]
 __do_sys_getdents64 fs/readdir.c:365 [inline]
 __se_sys_getdents64+0xbe/0x260 fs/readdir.c:354
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3478cf0d23
Code: 8b 05 d9 00 10 00 64 c7 00 16 00 00 00 31 c0 eb b0 66 0f 1f 44 00 00 b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 a1 00 10 00 f7 d8
RSP: 002b:00007ffe71221eb8 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00005638f5ef20b0 RCX: 00007f3478cf0d23
RDX: 0000000000008000 RSI: 00005638f5ef20e0 RDI: 000000000000000d
RBP: 00005638f5ef20b4 R08: 00007f3478df1ac0 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000293 R12: 00005638f5ef20e0
R13: fffffffffffffe68 R14: 0000000000000002 R15: 00007ffe71222190
 </TASK>