Commit ff9f9c6e authored by Dan Carpenter's avatar Dan Carpenter Committed by Michael S. Tsirkin
Browse files

vduse: fix memory corruption in vduse_dev_ioctl() 



The "config.offset" comes from the user.  There needs to a check to
prevent it being out of bounds.  The "config.offset" and
"dev->config_size" variables are both type u32.  So if the offset if
out of bounds then the "dev->config_size - config.offset" subtraction
results in a very high u32 value.  The out of bounds offset can result
in memory corruption.

Fixes: c8a6153b ("vduse: Introduce VDUSE - vDPA Device in Userspace")
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20211208103307.GA3778@kili


Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Cc: stable@vger.kernel.org
parent 0fcfb00b

drivers/vdpa/vdpa_user/vduse_dev.c

+2 −1
Original line number Diff line number Diff line
@@ -975,7 +975,8 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd, 
			break;



		ret = -EINVAL;

		if (config.length == 0 ||

		if (config.offset > dev->config_size ||

		    config.length == 0 ||

		    config.length > dev->config_size - config.offset)

			break;