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Subject: Re: A shift-out-of-bounds in minix_statfs in fs/minix/inode.c
To:     Theodore Ts'o <tytso@mit.edu>, Matthew Wilcox <willy@infradead.org>
Cc:     butt3rflyh4ck <butterflyhuangxx@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-fsdevel@vger.kernel.org,
        syzkaller-bugs <syzkaller-bugs@googlegroups.com>
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 <YPhbU/umyUZLdxIw@casper.infradead.org> <YPnp/zXp3saLbz03@mit.edu>
From:   Randy Dunlap <rdunlap@infradead.org>
Message-ID: <e494c34c-1118-584f-a001-2929df747f8b@infradead.org>
Date:   Thu, 22 Jul 2021 15:34:37 -0700
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On 7/22/21 2:58 PM, Theodore Ts'o wrote:
...

> 
> So I do care about this for ext4, although I don't guarantee immediate
> response, as it's something that I usually end up doing on my own
> time.  I do get cranky that Syzkaller makes it painful to extract out
> the fuzzed file system image, and I much prefer those fuzzing systems
> which provide the file system image and the C program used to trigger
> the failre as two seprate files.  Or failing that, if there was some

gosh yes. I have added a patch to the syzkaller C reproducer multiple times
so that it would write out the fs image and then I could just use that
with 'mount' etc. instead of running the (unreadable) C reproducer.

> trivial way to get the syzkaller reproducer program to disgorge the
> file system image to a specified output file.  As a result, if I have
> a choice of spending time investigating fuzzing report from a more
> file-system friendly fuzzing program and syzkaller, I'll tend choose
> to spend my time dealing with other file system fuzzing reports first.


-- 
~Randy