On Wed, May 29, 2019 at 05:14:17PM +0200, Dmitry Vyukov wrote:

quoted

It looks like

ommit 1515a63fc413f160d20574ab0894e7f1020c7be2
Author: Nikolay Aleksandrov [off-list ref]
Date:   Wed Apr 3 23:27:24 2019 +0300

    net: bridge: always clear mcast matching struct on reports and leaves

may have at least fixed the uninitialised value error.

The most up-to-date info is always available here:

quoted

quoted

dashboard link: https://syzkaller.appspot.com/bug?extid=bc5ab0af2dbf3b0ae897

It says no new crashes happened besides the original one.

We now have the following choices:

1. Invalidate with "#syz invalid"
2. Mark as tentatively fixed by that commit (could it fix it?) with
"#syz fix: net: bridge: always clear mcast matching struct on reports
and leaves"
3. Do nothing, then syzbot will auto-close it soon (bugs without
reproducers that did not happen in the past 180 days)

I'm still not quite sure how this could cause the use-after-free,
but it certainly seems to be the cause for the second issue of
uninit-value:

https://syzkaller.appspot.com/bug?extid=8dfe5ee27aa6d2e396c2

And this one does seem to have occured again recently (two months
ago).

Thanks,
-- 
Email: Herbert Xu [off-list ref]
Home Page: http://gondor.apana.org.au/~herbert/
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