This patch fixes sparse warnings about the memcmp function unsafely accessing
userspace memory without first copying it to kernel space.
Signed-off-by: Charlie Sands <sandsch@xxxxxxxxxxxxxxxxxxxxx>
---
V2: Fixed checkpatch.pl warning and changed variable name as suggested by Greg
K. H. and improved error checking on the "copy_from_user" function as suggested
by Pavel Skripkin.
V3: return -EFAULT from the function when there is a memory error while moving
it from user space to kernel space and fix incorrect subject from V2
drivers/staging/r8188eu/os_dep/ioctl_linux.c | 21 ++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)
diff --git a/drivers/staging/r8188eu/os_dep/ioctl_linux.c b/drivers/staging/r8188eu/os_dep/ioctl_linux.c
index 7df213856d66..9f2182b8e451 100644
--- a/drivers/staging/r8188eu/os_dep/ioctl_linux.c
+++ b/drivers/staging/r8188eu/os_dep/ioctl_linux.c
@@ -3233,23 +3233,28 @@ static int rtw_p2p_get(struct net_device *dev,
struct iw_request_info *info,
union iwreq_data *wrqu, char *extra)
{
- if (!memcmp(wrqu->data.pointer, "status", 6)) {
+ char wrqu_data[9];
+
+ if (copy_from_user(wrqu_data, wrqu->data.pointer, 9) != 0)
+ return -EFAULT;
+
+ if (!memcmp(wrqu_data, "status", 6)) {
rtw_p2p_get_status(dev, info, wrqu, extra);
- } else if (!memcmp(wrqu->data.pointer, "role", 4)) {
+ } else if (!memcmp(wrqu_data, "role", 4)) {
rtw_p2p_get_role(dev, info, wrqu, extra);
- } else if (!memcmp(wrqu->data.pointer, "peer_ifa", 8)) {
+ } else if (!memcmp(wrqu_data, "peer_ifa", 8)) {
rtw_p2p_get_peer_ifaddr(dev, info, wrqu, extra);
- } else if (!memcmp(wrqu->data.pointer, "req_cm", 6)) {
+ } else if (!memcmp(wrqu_data, "req_cm", 6)) {
rtw_p2p_get_req_cm(dev, info, wrqu, extra);
- } else if (!memcmp(wrqu->data.pointer, "peer_deva", 9)) {
+ } else if (!memcmp(wrqu_data, "peer_deva", 9)) {
/* Get the P2P device address when receiving the provision discovery request frame. */
rtw_p2p_get_peer_devaddr(dev, info, wrqu, extra);
- } else if (!memcmp(wrqu->data.pointer, "group_id", 8)) {
+ } else if (!memcmp(wrqu_data, "group_id", 8)) {
rtw_p2p_get_groupid(dev, info, wrqu, extra);
- } else if (!memcmp(wrqu->data.pointer, "peer_deva_inv", 9)) {
+ } else if (!memcmp(wrqu_data, "peer_deva_inv", 9)) {
/* Get the P2P device address when receiving the P2P Invitation request frame. */
rtw_p2p_get_peer_devaddr_by_invitation(dev, info, wrqu, extra);
- } else if (!memcmp(wrqu->data.pointer, "op_ch", 5)) {
+ } else if (!memcmp(wrqu_data, "op_ch", 5)) {
rtw_p2p_get_op_ch(dev, info, wrqu, extra);
}
return 0;
--
2.35.1
