From: butt3rflyh4ck <butterflyhuangxx@gmail.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
linux-fsdevel@vger.kernel.org,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
djwong@kernel.org
Subject: Re: A shift-out-of-bounds in minix_statfs in fs/minix/inode.c
Date: Thu, 22 Jul 2021 10:43:10 +0800 [thread overview]
Message-ID: <CAFcO6XO0GR8GBVD7hT8VL5qey3cCYriMqvt0Dan72i5yVP6FxQ@mail.gmail.com> (raw)
In-Reply-To: <YPhbU/umyUZLdxIw@casper.infradead.org>
On Thu, Jul 22, 2021 at 1:37 AM Matthew Wilcox <willy@infradead.org> wrote:
>
> On Thu, Jul 22, 2021 at 01:14:06AM +0800, butt3rflyh4ck wrote:
> > ms = (struct minix_super_block *) bh->b_data; /// --------------> set
> > minix_super_block pointer
> > sbi->s_ms = ms;
> > sbi->s_sbh = bh;
> > sbi->s_mount_state = ms->s_state;
> > sbi->s_ninodes = ms->s_ninodes;
> > sbi->s_nzones = ms->s_nzones;
> > sbi->s_imap_blocks = ms->s_imap_blocks;
> > sbi->s_zmap_blocks = ms->s_zmap_blocks;
> > sbi->s_firstdatazone = ms->s_firstdatazone;
> > sbi->s_log_zone_size = ms->s_log_zone_size; // ------------------>
> > set sbi->s_log_zone_size
>
> So what you're saying is that if you construct a malicious minix image,
> you can produce undefined behaviour?
Yes, the attachment is a reproduction. just compile it and run.
>That's not something we're
> traditionally interested in, unless the filesystem is one customarily
> used for data interchange (like FAT or iso9660).
>
These file systems are my fuzzing targets.
Regards,
butt3rflyh4ck.
--
Active Defense Lab of Venustech
next prev parent reply other threads:[~2021-07-22 2:43 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-21 17:14 A shift-out-of-bounds in minix_statfs in fs/minix/inode.c butt3rflyh4ck
2021-07-21 17:37 ` Matthew Wilcox
2021-07-21 19:14 ` Darrick J. Wong
2021-07-22 2:43 ` butt3rflyh4ck [this message]
2021-07-22 2:52 ` Matthew Wilcox
2021-07-22 8:09 ` Dan Carpenter
2021-07-22 21:58 ` Theodore Ts'o
2021-07-22 22:34 ` Randy Dunlap
2021-07-23 9:22 ` Christian Brauner
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