[syzbot] [bpf?] possible deadlock in __queue_map_get

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Apr 13, 2024, 1:14:44 AMApr 13
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Hello,

syzbot found the following issue on:

HEAD commit: f99c5f563c17 Merge tag 'nf-24-03-21' of git://git.kernel.o..
git tree: net
console+strace: https://syzkaller.appspot.com/x/log.txt?x=140c3f8d180000
kernel config: https://syzkaller.appspot.com/x/.config?x=6fb1be60a193d440
dashboard link: https://syzkaller.appspot.com/bug?extid=8bdfc2c53fb2b63e1871
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16975413180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11062cf3180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/65d3f3eb786e/disk-f99c5f56.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/799cf7f28ff8/vmlinux-f99c5f56.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ab26c60c3845/bzImage-f99c5f56.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8bdfc2...@syzkaller.appspotmail.com

============================================
WARNING: possible recursive locking detected
6.8.0-syzkaller-05271-gf99c5f563c17 #0 Not tainted
--------------------------------------------
strace-static-x/5063 is trying to acquire lock:
ffff8880233421d8 (&qs->lock){-.-.}-{2:2}, at: __queue_map_get+0x14b/0x4d0 kernel/bpf/queue_stack_maps.c:105

but task is already holding lock:
ffff8880233401d8 (&qs->lock){-.-.}-{2:2}, at: __queue_map_get+0x14b/0x4d0 kernel/bpf/queue_stack_maps.c:105

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 strace-static-x/5063:
#0: ffff88807c3d6c68 (&pipe->mutex){+.+.}-{3:3}, at: pipe_write+0x1c9/0x1a40 fs/pipe.c:455
#1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
#1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
#1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline]
#1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x114/0x420 kernel/trace/bpf_trace.c:2420
#2: ffff8880233401d8 (&qs->lock){-.-.}-{2:2}, at: __queue_map_get+0x14b/0x4d0 kernel/bpf/queue_stack_maps.c:105
#3: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
#3: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
#3: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline]
#3: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x114/0x420 kernel/trace/bpf_trace.c:2420

stack backtrace:
CPU: 0 PID: 5063 Comm: strace-static-x Not tainted 6.8.0-syzkaller-05271-gf99c5f563c17 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
check_deadlock kernel/locking/lockdep.c:3062 [inline]
validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856
__lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
lock_acquire+0x1e4/0x530 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_bf9a7c5adf7f532a+0x42/0x46
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+0x204/0x420 kernel/trace/bpf_trace.c:2420
__traceiter_contention_end+0x7b/0xb0 include/trace/events/lock.h:122
trace_contention_end+0xf6/0x120 include/trace/events/lock.h:122
__pv_queued_spin_lock_slowpath+0x939/0xc60 kernel/locking/qspinlock.c:560
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
__queue_map_get+0x14b/0x4d0 kernel/bpf/queue_stack_maps.c:105
bpf_prog_bf9a7c5adf7f532a+0x42/0x46
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+0x204/0x420 kernel/trace/bpf_trace.c:2420
__traceiter_contention_end+0x7b/0xb0 include/trace/events/lock.h:122
trace_contention_end+0xd7/0x100 include/trace/events/lock.h:122
__mutex_lock_common kernel/locking/mutex.c:617 [inline]
__mutex_lock+0x2e5/0xd70 kernel/locking/mutex.c:752
pipe_write+0x1c9/0x1a40 fs/pipe.c:455
call_write_iter include/linux/fs.h:2108 [inline]
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0xa84/0xcb0 fs/read_write.c:590
ksys_write+0x1a0/0x2c0 fs/read_write.c:643
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x4e8593
Code: c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 64 8b 04 25 18 00 00 00 85 c0 75 14 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 55 c3 0f 1f 40 00 48 83 ec 28 48 89 54 24 18
RSP: 002b:00007ffc411c1eb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000002c RCX: 00000000004e8593
RDX: 000000000000002c RSI: 000000001b0c0140 RDI: 0000000000000002
RBP: 000000001b0c0140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000002c
R13: 000000000063f460 R14: 000000000000002c R15: 0000000000000001
</TASK>


---
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