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[SRU,T/A,1/1] cdrom: information leak in cdrom_ioctl_media_changed()

Message ID 20180709213901.7570-2-khalid.elmously@canonical.com
State New
Headers show
Series Fix for CVE-2018-10940 | expand

Commit Message

Khalid Elmously July 9, 2018, 9:39 p.m. UTC 
From: Dan Carpenter <dan.carpenter@oracle.com>

CVE-2018-10940

This cast is wrong.  "cdi->capacity" is an int and "arg" is an unsigned
long.  The way the check is written now, if one of the high 32 bits is
set then we could read outside the info->slots[] array.

This bug is pretty old and it predates git.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
(cherry-picked from 9de4ee40547fd315d4a0ed1dd15a2fa3559ad707)
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
---
 drivers/cdrom/cdrom.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Stefan Bader July 19, 2018, 12:26 p.m. UTC | #1 
On 09.07.2018 23:39, Khalid Elmously wrote:
> From: Dan Carpenter <dan.carpenter@oracle.com>
> 
> CVE-2018-10940
> 
> This cast is wrong.  "cdi->capacity" is an int and "arg" is an unsigned
> long.  The way the check is written now, if one of the high 32 bits is
> set then we could read outside the info->slots[] array.
> 
> This bug is pretty old and it predates git.
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Cc: stable@vger.kernel.org
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> (cherry-picked from 9de4ee40547fd315d4a0ed1dd15a2fa3559ad707)
> Signed-off-by: Khalid Elmously <khalid.elmously@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 a7f37f104d6c..589a770f4270 100644
> --- a/drivers/cdrom/cdrom.c
> +++ b/drivers/cdrom/cdrom.c
> @@ -2374,7 +2374,7 @@ static int cdrom_ioctl_media_changed(struct cdrom_device_info *cdi,
>  	if (!CDROM_CAN(CDC_SELECT_DISC) || arg == CDSL_CURRENT)
>  		return media_changed(cdi, 1);
>  
> -	if ((unsigned int)arg >= cdi->capacity)
> +	if (arg >= cdi->capacity)
>  		return -EINVAL;
>  
>  	info = kmalloc(sizeof(*info), GFP_KERNEL);
>
diff mbox series

Patch

diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index a7f37f104d6c..589a770f4270 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2374,7 +2374,7 @@  static int cdrom_ioctl_media_changed(struct cdrom_device_info *cdi,
 	if (!CDROM_CAN(CDC_SELECT_DISC) || arg == CDSL_CURRENT)
 		return media_changed(cdi, 1);
 
-	if ((unsigned int)arg >= cdi->capacity)
+	if (arg >= cdi->capacity)
 		return -EINVAL;
 
 	info = kmalloc(sizeof(*info), GFP_KERNEL);