[CVE-2010-4529 Karmic] irda: prevent integer underflow in IRLMP_ENUMDEVICES, CVE-2010-4529
Stefan Bader
stefan.bader at canonical.com
Tue Mar 22 15:14:46 UTC 2011
On 03/21/2011 08:17 PM, Leann Ogasawara wrote:
> The following changes since commit d57e49668c98881fc4daab39ea71dc24f838ea85:
> Leann Ogasawara (1):
> sound: Prevent buffer overflow in OSS load_mixer_volumes, CVE-2010-4527
>
> are available in the git repository at:
>
> git://kernel.ubuntu.com/ogasawara/ubuntu-karmic.git CVE-2010-4529
>
> Dan Rosenberg (1):
> irda: prevent integer underflow in IRLMP_ENUMDEVICES, CVE-2010-4529
>
> net/irda/af_irda.c | 16 +++++++++-------
> 1 files changed, 9 insertions(+), 7 deletions(-)
>
> From bbe20d84f2bc23756faf61ad1ca4e750b41d0e30 Mon Sep 17 00:00:00 2001
> From: Dan Rosenberg <drosenberg at vsecurity.com>
> Date: Wed, 22 Dec 2010 13:58:27 +0000
> Subject: [PATCH] irda: prevent integer underflow in IRLMP_ENUMDEVICES, CVE-2010-4529
>
> CVE-2010-4529
>
> BugLink: http://bugs.launchpad.net/bugs/737823
>
> If the user-provided len is less than the expected offset, the
> IRLMP_ENUMDEVICES getsockopt will do a copy_to_user() with a very large
> size value. While this isn't be a security issue on x86 because it will
> get caught by the access_ok() check, it may leak large amounts of kernel
> heap on other architectures. In any event, this patch fixes it.
>
> Signed-off-by: Dan Rosenberg <drosenberg at vsecurity.com>
> Signed-off-by: David S. Miller <davem at davemloft.net>
> (backport of upstream commit fdac1e0697356ac212259f2147aa60c72e334861)
>
> Signed-off-by: Leann Ogasawara <leann.ogasawara at canonical.com>
> ---
> net/irda/af_irda.c | 16 +++++++++-------
> 1 files changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/net/irda/af_irda.c b/net/irda/af_irda.c
> index ad88268..a93afad 100644
> --- a/net/irda/af_irda.c
> +++ b/net/irda/af_irda.c
> @@ -2164,6 +2164,14 @@ static int irda_getsockopt(struct socket *sock, int level, int optname,
>
> switch (optname) {
> case IRLMP_ENUMDEVICES:
> +
> + /* Offset to first device entry */
> + offset = sizeof(struct irda_device_list) -
> + sizeof(struct irda_device_info);
> +
> + if (len < offset)
> + return -EINVAL;
> +
> /* Ask lmp for the current discovery log */
> discoveries = irlmp_get_discoveries(&list.len, self->mask.word,
> self->nslots);
> @@ -2173,15 +2181,9 @@ static int irda_getsockopt(struct socket *sock, int level, int optname,
> err = 0;
>
> /* Write total list length back to client */
> - if (copy_to_user(optval, &list,
> - sizeof(struct irda_device_list) -
> - sizeof(struct irda_device_info)))
> + if (copy_to_user(optval, &list, offset))
> err = -EFAULT;
>
> - /* Offset to first device entry */
> - offset = sizeof(struct irda_device_list) -
> - sizeof(struct irda_device_info);
> -
> /* Copy the list itself - watch for overflow */
> if(list.len > 2048)
> {
Acked-by: Stefan Bader <stefan.bader at canonical.com>
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