From: Jeff Layton <jlayton@samba.org>
To: Dan Carpenter <dan.carpenter-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Cc: Steve French <sfrench-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org>,
linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
samba-technical-w/Ol4Ecudpl8XjKLYN78aQ@public.gmane.org,
kernel-janitors-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [patch] cifs: integer overflow in parse_dacl()
Date: Wed, 11 Jan 2012 12:20:29 +0000 [thread overview]
Message-ID: <20120111072029.672dfdca@tlielax.poochiereds.net> (raw)
In-Reply-To: <20120111074627.GA4519-mgFCXtclrQlZLf2FXnZxJA@public.gmane.org>
On Wed, 11 Jan 2012 10:46:27 +0300
Dan Carpenter <dan.carpenter@oracle.com> wrote:
> On 32 bit systems num_aces * sizeof(struct cifs_ace *) could overflow
> leading to a smaller ppace buffer than we expected.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
> index 72ddf23..c1b2544 100644
> --- a/fs/cifs/cifsacl.c
> +++ b/fs/cifs/cifsacl.c
> @@ -909,6 +909,8 @@ static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl,
> umode_t group_mask = S_IRWXG;
> umode_t other_mask = S_IRWXU | S_IRWXG | S_IRWXO;
>
> + if (num_aces > ULONG_MAX / sizeof(struct cifs_ace *))
> + return;
> ppace = kmalloc(num_aces * sizeof(struct cifs_ace *),
> GFP_KERNEL);
> if (!ppace) {
Looks plausible. This function could use some work. I'm not sure why
num_aces is signed here too...
The first arg to kmalloc is a size_t. Does that boil down to an unsigned
long on all arches?
--
Jeff Layton <jlayton@samba.org>
next prev parent reply other threads:[~2012-01-11 12:20 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-11 7:46 [patch] cifs: integer overflow in parse_dacl() Dan Carpenter
[not found] ` <20120111074627.GA4519-mgFCXtclrQlZLf2FXnZxJA@public.gmane.org>
2012-01-11 12:20 ` Jeff Layton [this message]
[not found] ` <20120111072029.672dfdca-9yPaYZwiELC+kQycOl6kW4xkIHaj4LzF@public.gmane.org>
2012-01-11 12:41 ` Dan Carpenter
2012-01-11 13:33 ` Jeff Layton
2012-01-11 15:50 ` Shirish Pargaonkar
[not found] ` <CADT32eLVwQT9V67BX8TkjVHDnQoYS7OqA_-xbnjY57ZXO3EfsA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-01-11 17:24 ` Steve French
[not found] ` <CAH2r5muDQUL=0HcoFHH3QvP7C2pyy0=S9ESFBcm=qOYg3ESdxQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-01-11 18:20 ` Jeff Layton
[not found] ` <20120111132053.467e8cae-9yPaYZwiELC+kQycOl6kW4xkIHaj4LzF@public.gmane.org>
2012-01-11 18:31 ` Steve French
[not found] ` <CAH2r5msciOkxvxTrQrN9mKKCiJvM_anmxU7sag_TGk92LoKEwQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-01-12 7:06 ` Dan Carpenter
2012-01-12 19:17 ` Steve French
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