Re: WARNING in cbq_destroy

From: Cong Wang
Date: Thu Jan 23 2020 - 13:14:54 EST


On Tue, Jan 21, 2020 at 10:57 PM syzbot
<syzbot+63bdb6006961d8c917c6@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: d96d875e Merge tag 'fixes_for_v5.5-rc8' of git://git.kerne..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=144f7601e00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=83c00afca9cf5153
> dashboard link: https://syzkaller.appspot.com/bug?extid=63bdb6006961d8c917c6
> compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17a1a721e00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11a91a95e00000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+63bdb6006961d8c917c6@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> netlink: 96 bytes leftover after parsing attributes in process `syz-executor899'.
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 8828 at net/sched/sch_cbq.c:1437 cbq_destroy_class net/sched/sch_cbq.c:1437 [inline]
> WARNING: CPU: 1 PID: 8828 at net/sched/sch_cbq.c:1437 cbq_destroy+0x324/0x400 net/sched/sch_cbq.c:1471


Just FYI: I am still working on a fix, which is more complicated than I thought.

Thanks.