| From ff9f9c6e74848170fcb45c8403c80d661484c8c9 Mon Sep 17 00:00:00 2001 |
| From: Dan Carpenter <dan.carpenter@oracle.com> |
| Date: Wed, 8 Dec 2021 13:33:07 +0300 |
| Subject: vduse: fix memory corruption in vduse_dev_ioctl() |
| |
| From: Dan Carpenter <dan.carpenter@oracle.com> |
| |
| commit ff9f9c6e74848170fcb45c8403c80d661484c8c9 upstream. |
| |
| 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: c8a6153b6c59 ("vduse: Introduce VDUSE - vDPA Device in Userspace") |
| Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> |
| Link: https://lore.kernel.org/r/20211208103307.GA3778@kili |
| Signed-off-by: Michael S. Tsirkin <mst@redhat.com> |
| Cc: stable@vger.kernel.org |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/vdpa/vdpa_user/vduse_dev.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/vdpa/vdpa_user/vduse_dev.c |
| +++ b/drivers/vdpa/vdpa_user/vduse_dev.c |
| @@ -975,7 +975,8 @@ static long vduse_dev_ioctl(struct file |
| break; |
| |
| ret = -EINVAL; |
| - if (config.length == 0 || |
| + if (config.offset > dev->config_size || |
| + config.length == 0 || |
| config.length > dev->config_size - config.offset) |
| break; |
| |