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;