Re: [syzbot] memory leak in xas_create
From: Dmitry Vyukov
Date: Tue Jul 12 2022 - 02:54:53 EST
On Mon, 11 Jul 2022 at 22:47, Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote:
> On Mon, Jul 11, 2022 at 01:38:08PM -0700, Andrew Morton wrote:
> > On Sat, 09 Jul 2022 00:13:23 -0700 syzbot <syzbot+a785d07959bc94837d51@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> > > Hello,
> > >
> > > syzbot found the following issue on:
> > >
> > > HEAD commit: c1084b6c5620 Merge tag 'soc-fixes-5.19-2' of git://git.ker..
> > > git tree: upstream
> > > console output: https://syzkaller.appspot.com/x/log.txt?x=14967ccc080000
> > > kernel config: https://syzkaller.appspot.com/x/.config?x=916233b7694a38ff
> > > dashboard link: https://syzkaller.appspot.com/bug?extid=a785d07959bc94837d51
> > > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=122ae834080000
> > >
> > > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > > Reported-by: syzbot+a785d07959bc94837d51@xxxxxxxxxxxxxxxxxxxxxxxxx
> > >
> > > 2022/07/05 05:22:17 executed programs: 828
> > > 2022/07/05 05:22:23 executed programs: 846
> > > 2022/07/05 05:22:30 executed programs: 866
> > > 2022/07/05 05:22:37 executed programs: 875
> > > BUG: memory leak
> > Thanks. Presumably due to khugepaged changes.
> Huh, I was expecting it to be something I'd messed up. I've been
> looking at it today, but no luck figuring it out so far.
> > Can we expect a bisection search?
> We only have a syz reproducer so far, and if I understand correctly,
> it's probably because this is a flaky test (because it's trying to
> find something that's a race condition).
> I expect a bisection search to go badly wrong if this is true.
Is it possible that parts of xas are not freed on the error paths?
I don't immediately see where anything is freed on these error paths: