From: Bob Copeland <me@bobcopeland.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Fabian Frederick <fabf@skynet.be>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 1/1] fs/omfs/inode.c: replace count*size kzalloc by kcalloc
Date: Wed, 25 Jun 2014 15:02:50 -0400 [thread overview]
Message-ID: <20140625190250.GB399@localhost> (raw)
In-Reply-To: <CA+55aFypOwqaxfMwG5H8QSsRyMrMV7ibW_k5CQdc=EPXYmrfLg@mail.gmail.com>
On Wed, Jun 25, 2014 at 11:27:21AM -0700, Linus Torvalds wrote:
> On Wed, Jun 25, 2014 at 11:17 AM, Fabian Frederick <fabf@skynet.be> wrote:
> > kcalloc manages count*sizeof overflow.
>
> As far as I can tell, any overflow has happened long before, in
>
> bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8);
>
> where 'sbi->s_num_blocks' i san u64, and 'bitmap_size' is an 'int'.
>
> I don't think the patch is necessarily a bad thing, but I think it
> might be more important to sanity-check that part instead.
Agreed - even though the FS data structures support 64-bit block
count, I've never seen an OMFS fs with more than about 2M blocks
(typical device had 20 gigs w/ 8k blocks). So it would make
sense to bail in omfs_fill_super if that number is greater than
2^31 or so.
(I am fine with the kcalloc patch too, though.)
--
Bob Copeland %% www.bobcopeland.com
next prev parent reply other threads:[~2014-06-25 19:03 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-25 18:17 [PATCH 1/1] fs/omfs/inode.c: replace count*size kzalloc by kcalloc Fabian Frederick
2014-06-25 18:27 ` Linus Torvalds
2014-06-25 19:02 ` Bob Copeland [this message]
2014-06-25 20:03 ` Fabian Frederick
2014-06-25 20:28 ` Bob Copeland
2014-06-25 19:05 ` Bob Copeland
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