Re: [PATCH] staging: r8188eu: Fix unsafe memory access by memcmp.

From: Pavel Skripkin
Date: Sun Apr 03 2022 - 07:20:26 EST


Hi Charlie,

On 4/1/22 23:12, Charlie Sands wrote:
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>
---
drivers/staging/r8188eu/os_dep/ioctl_linux.c | 20 ++++++++++++--------
1 file changed, 12 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..1cfac1b27eb7 100644
--- a/drivers/staging/r8188eu/os_dep/ioctl_linux.c
+++ b/drivers/staging/r8188eu/os_dep/ioctl_linux.c
@@ -3233,23 +3233,27 @@ 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_ptr[9];
+ if (copy_from_user(wrqu_data_ptr, wrqu->data.pointer, 9))
+ return 0;

-EFAULT is standard return value in case of `copy_{to_from}_user` failure



With regards,
Pavel Skripkin