[CVE-2018-16658,Trusty,Bionic,SRU,1/1] cdrom: Fix info leak/OOB read in cdrom_ioctl_drive_status

Message ID 20181003062939.16699-2-po-hsu.lin@canonical.com
State New
Headers show
Series
  • Fix for CVE-2018-16658
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Commit Message

Po-Hsu Lin Oct. 3, 2018, 6:29 a.m.
From: Scott Bauer <scott.bauer@intel.com>

CVE-2018-16658

Like d88b6d04: "cdrom: information leak in cdrom_ioctl_media_changed()"

There is another cast from unsigned long to int which causes
a bounds check to fail with specially crafted input. The value is
then used as an index in the slot array in cdrom_slot_status().

Signed-off-by: Scott Bauer <scott.bauer@intel.com>
Signed-off-by: Scott Bauer <sbauer@plzdonthack.me>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
(cherry picked from commit 8f3fafc9c2f0ece10832c25f7ffcb07c97a32ad4)
Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com>
---
 drivers/cdrom/cdrom.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Stefan Bader Oct. 8, 2018, 7:15 a.m. | #1
On 03.10.2018 08:29, Po-Hsu Lin wrote:
> From: Scott Bauer <scott.bauer@intel.com>
> 
> CVE-2018-16658
> 
> Like d88b6d04: "cdrom: information leak in cdrom_ioctl_media_changed()"
> 
> There is another cast from unsigned long to int which causes
> a bounds check to fail with specially crafted input. The value is
> then used as an index in the slot array in cdrom_slot_status().
> 
> Signed-off-by: Scott Bauer <scott.bauer@intel.com>
> Signed-off-by: Scott Bauer <sbauer@plzdonthack.me>
> Cc: stable@vger.kernel.org
> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> (cherry picked from commit 8f3fafc9c2f0ece10832c25f7ffcb07c97a32ad4)
> Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
> ---
>  drivers/cdrom/cdrom.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
> index cbee2e7..f0534a4 100644
> --- a/drivers/cdrom/cdrom.c
> +++ b/drivers/cdrom/cdrom.c
> @@ -2542,7 +2542,7 @@ static int cdrom_ioctl_drive_status(struct cdrom_device_info *cdi,
>  	if (!CDROM_CAN(CDC_SELECT_DISC) ||
>  	    (arg == CDSL_CURRENT || arg == CDSL_NONE))
>  		return cdi->ops->drive_status(cdi, CDSL_CURRENT);
> -	if (((int)arg >= cdi->capacity))
> +	if (arg >= cdi->capacity)
>  		return -EINVAL;
>  	return cdrom_slot_status(cdi, arg);
>  }
>
Kleber Souza Oct. 11, 2018, 11:56 a.m. | #2
On 10/03/18 08:29, Po-Hsu Lin wrote:
> From: Scott Bauer <scott.bauer@intel.com>
> 
> CVE-2018-16658
> 
> Like d88b6d04: "cdrom: information leak in cdrom_ioctl_media_changed()"
> 
> There is another cast from unsigned long to int which causes
> a bounds check to fail with specially crafted input. The value is
> then used as an index in the slot array in cdrom_slot_status().
> 
> Signed-off-by: Scott Bauer <scott.bauer@intel.com>
> Signed-off-by: Scott Bauer <sbauer@plzdonthack.me>
> Cc: stable@vger.kernel.org
> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> (cherry picked from commit 8f3fafc9c2f0ece10832c25f7ffcb07c97a32ad4)
> Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com>

Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

> ---
>  drivers/cdrom/cdrom.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
> index cbee2e7..f0534a4 100644
> --- a/drivers/cdrom/cdrom.c
> +++ b/drivers/cdrom/cdrom.c
> @@ -2542,7 +2542,7 @@ static int cdrom_ioctl_drive_status(struct cdrom_device_info *cdi,
>  	if (!CDROM_CAN(CDC_SELECT_DISC) ||
>  	    (arg == CDSL_CURRENT || arg == CDSL_NONE))
>  		return cdi->ops->drive_status(cdi, CDSL_CURRENT);
> -	if (((int)arg >= cdi->capacity))
> +	if (arg >= cdi->capacity)
>  		return -EINVAL;
>  	return cdrom_slot_status(cdi, arg);
>  }
>

Patch

diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index cbee2e7..f0534a4 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2542,7 +2542,7 @@  static int cdrom_ioctl_drive_status(struct cdrom_device_info *cdi,
 	if (!CDROM_CAN(CDC_SELECT_DISC) ||
 	    (arg == CDSL_CURRENT || arg == CDSL_NONE))
 		return cdi->ops->drive_status(cdi, CDSL_CURRENT);
-	if (((int)arg >= cdi->capacity))
+	if (arg >= cdi->capacity)
 		return -EINVAL;
 	return cdrom_slot_status(cdi, arg);
 }