From: Dan Carpenter Date: Wed, 18 Apr 2018 09:51:31 +0000 (+0300) Subject: cdrom: information leak in cdrom_ioctl_media_changed() X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=9de4ee40547fd315d4a0ed1dd15a2fa3559ad707;p=openwrt%2Fstaging%2Fblogic.git cdrom: information leak in cdrom_ioctl_media_changed() 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 Cc: stable@vger.kernel.org Signed-off-by: Dan Carpenter Signed-off-by: Jens Axboe --- diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c index 8327478effd0..bfc566d3f31a 100644 --- a/drivers/cdrom/cdrom.c +++ b/drivers/cdrom/cdrom.c @@ -2371,7 +2371,7 @@ 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);