From: Eric Sandeen <sandeen@sandeen.net>
To: Eric Sandeen <sandeen@redhat.com>, xfs-oss <xfs@oss.sgi.com>
Subject: Re: [PATCH] xfs: catch invalid negative blknos in _xfs_buf_find()
Date: Wed, 19 Nov 2014 16:27:25 -0600 [thread overview]
Message-ID: <546D194D.2010600@sandeen.net> (raw)
In-Reply-To: <546D15E3.5000200@redhat.com>
On 11/19/14 4:12 PM, Eric Sandeen wrote:
> Here blkno is a daddr_t, which is a __s64; it's possible to hold
> a value which is negative, and thus pass the (blkno >= eofs)
> test. Then we try to do a xfs_perag_get() for a ridiculous
> agno via xfs_daddr_to_agno(), and bad things happen when that
> fails, and returns a null pag which is dereferenced shortly
> thereafter.
>
> Found via a user-supplied fuzzed image...
NAK - this needs a bit more love; if we catch this and fail,
the caller may still do something crazy with this data.
V2 coming in a bit.
-Eric
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next prev parent reply other threads:[~2014-11-19 22:27 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-19 22:12 [PATCH] xfs: catch invalid negative blknos in _xfs_buf_find() Eric Sandeen
2014-11-19 22:27 ` Eric Sandeen [this message]
2014-11-26 15:58 ` Eric Sandeen
2014-11-26 16:38 ` Mark Tinguely
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