From 15bad6c8291a04692b928e9037844fde6f32a798 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 18 Apr 2018 12:51:31 +0300 Subject: [PATCH] cdrom: information leak in cdrom_ioctl_media_changed() commit 9de4ee40547fd315d4a0ed1dd15a2fa3559ad707 upstream. 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 Signed-off-by: Dan Carpenter Signed-off-by: Jens Axboe Signed-off-by: Ben Hutchings --- 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 a03e849158d4..3792f5cbc8e8 100644 --- a/drivers/cdrom/cdrom.c +++ b/drivers/cdrom/cdrom.c @@ -2342,7 +2342,7 @@ 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); -- 2.30.2