From: tytso@mit.edu
To: Eric Sandeen <sandeen@redhat.com>
Cc: "linux-ext4@vger.kernel.org" <linux-ext4@vger.kernel.org>
Subject: Re: [PATCH 1/1] ext4: fix potential negative array index in do_split()
Date: Wed, 29 Jul 2020 21:48:35 -0400 [thread overview]
Message-ID: <20200730014835.GC44720@mit.edu> (raw)
In-Reply-To: <f53e246b-647c-64bb-16ec-135383c70ad7@redhat.com>
On Wed, Jun 17, 2020 at 02:19:04PM -0500, Eric Sandeen wrote:
> If for any reason a directory passed to do_split() does not have enough
> active entries to exceed half the size of the block, we can end up
> iterating over all "count" entries without finding a split point.
>
> In this case, count == move, and split will be zero, and we will
> attempt a negative index into map[].
>
> Guard against this by detecting this case, and falling back to
> split-to-half-of-count instead; in this case we will still have
> plenty of space (> half blocksize) in each split block.
>
> Fixes: ef2b02d3e617 ("ext34: ensure do_split leaves enough free space in both blocks")
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Thanks, applied.
- Ted
next prev parent reply other threads:[~2020-07-30 1:48 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-17 19:01 [PATCH 0/1] ext4: fix potential negative array index in do_split Eric Sandeen
2020-06-17 19:19 ` [PATCH 1/1] ext4: fix potential negative array index in do_split() Eric Sandeen
2020-06-19 0:33 ` Andreas Dilger
2020-06-19 6:41 ` Lukas Czerner
2020-06-19 7:08 ` Lukas Czerner
2020-06-19 11:16 ` Lukas Czerner
2020-06-19 13:44 ` Eric Sandeen
2020-06-19 13:53 ` Lukas Czerner
2020-06-19 13:42 ` Eric Sandeen
2020-06-19 13:49 ` Lukas Czerner
2020-06-19 13:39 ` Eric Sandeen
2020-07-08 16:09 ` Jan Kara
2020-07-30 1:48 ` tytso [this message]
2020-06-19 2:31 ` [PATCH 0/1] ext4: fix potential negative array index in do_split Andreas Dilger
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