On Mon, Aug 25, 2025 at 7:20 PM Leon Hwang <hffilwlqm@xxxxxxxxx> wrote: > > > > On 26/8/25 01:39, syzbot wrote: > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: dd9de524183a xsk: Fix immature cq descriptor production > > git tree: bpf > > console output: https://syzkaller.appspot.com/x/log.txt?x=102da862580000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=c321f33e4545e2a1 > > dashboard link: https://syzkaller.appspot.com/bug?extid=fa5c2814795b5adca240 > > compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=142da862580000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1588aef0580000 > > > > Downloadable assets: > > disk image: https://storage.googleapis.com/syzbot-assets/5a3389c1558f/disk-dd9de524.raw.xz > > vmlinux: https://storage.googleapis.com/syzbot-assets/c97133192a27/vmlinux-dd9de524.xz > > kernel image: https://storage.googleapis.com/syzbot-assets/3ae5a1a88637/bzImage-dd9de524.xz > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+fa5c2814795b5adca240@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > ============================================ > > WARNING: possible recursive locking detected > > syzkaller #0 Not tainted > > -------------------------------------------- > > syz-execprog/5866 is trying to acquire lock: > > ffffc900048c10d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1c7/0x5a0 kernel/bpf/ringbuf.c:423 > > > > but task is already holding lock: > > ffffc900048e90d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1c7/0x5a0 kernel/bpf/ringbuf.c:423 > > > > 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 > > Confirmed. > > I can reproduce this deadlock issue and will work on a fix. Don't. It's due to revert. Once rqspinlock is fixed the revert will be reverted.
