2021-12-09 07:36:02

by Jianglei Nie

Subject: [PATCH] staging: r8188eu: fix a memory leak in rtw_mp_QueryDrv()

Line 6183 (#1) allocates a memory chunk for input by kmalloc().
Line 6204 (#3) frees the input before the function returns while
line 6190 (#2) forget to free it, which will lead to a memory leak.

We should kfree() input in line 6190 (#2).

6177 static int rtw_mp_QueryDrv(struct net_device *dev,
6178 struct iw_request_info *info,
6179 union iwreq_data *wrqu, char *extra)
6180 {
6182 char *input = kmalloc(wrqu->data.length, GFP_KERNEL);
// #1: kmalloc space

6186 if (!input)
6187 return -ENOMEM;

6189 if (copy_from_user(input, wrqu->data.pointer, wrqu->data.length))
6190 return -EFAULT; // #2: missing kfree

6204 kfree(input); // #3: kfree space
6205 return 0;
6206 }

Signed-off-by: Jianglei Nie <[email protected]>
---
drivers/staging/r8188eu/os_dep/ioctl_linux.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/r8188eu/os_dep/ioctl_linux.c b/drivers/staging/r8188eu/os_dep/ioctl_linux.c
index 1fd375076001..0524523910f0 100644
--- a/drivers/staging/r8188eu/os_dep/ioctl_linux.c
+++ b/drivers/staging/r8188eu/os_dep/ioctl_linux.c
@@ -6186,8 +6186,11 @@ static int rtw_mp_QueryDrv(struct net_device *dev,
if (!input)
return -ENOMEM;

- if (copy_from_user(input, wrqu->data.pointer, wrqu->data.length))
- return -EFAULT;
+ if (copy_from_user(input, wrqu->data.pointer, wrqu->data.length)) {
+ kfree(input);
+ return -EFAULT;
+ }
+
DBG_88E("%s:iwpriv in =%s\n", __func__, input);

qAutoLoad = strncmp(input, "autoload", 8); /* strncmp true is 0 */
--
2.25.1

2021-12-09 08:00:06

by Greg Kroah-Hartman

Subject: Re: [PATCH] staging: r8188eu: fix a memory leak in rtw_mp_QueryDrv()

On Thu, Dec 09, 2021 at 03:34:21PM +0800, Jianglei Nie wrote:
> Line 6183 (#1) allocates a memory chunk for input by kmalloc().
> Line 6204 (#3) frees the input before the function returns while
> line 6190 (#2) forget to free it, which will lead to a memory leak.
>
> We should kfree() input in line 6190 (#2).
>
> 6177 static int rtw_mp_QueryDrv(struct net_device *dev,
> 6178 struct iw_request_info *info,
> 6179 union iwreq_data *wrqu, char *extra)
> 6180 {
> 6182 char *input = kmalloc(wrqu->data.length, GFP_KERNEL);
> // #1: kmalloc space
>
> 6186 if (!input)
> 6187 return -ENOMEM;
>
> 6189 if (copy_from_user(input, wrqu->data.pointer, wrqu->data.length))
> 6190 return -EFAULT; // #2: missing kfree
>
> 6204 kfree(input); // #3: kfree space
> 6205 return 0;
> 6206 }
>
> Signed-off-by: Jianglei Nie <[email protected]>
> ---
> drivers/staging/r8188eu/os_dep/ioctl_linux.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/staging/r8188eu/os_dep/ioctl_linux.c b/drivers/staging/r8188eu/os_dep/ioctl_linux.c
> index 1fd375076001..0524523910f0 100644
> --- a/drivers/staging/r8188eu/os_dep/ioctl_linux.c
> +++ b/drivers/staging/r8188eu/os_dep/ioctl_linux.c
> @@ -6186,8 +6186,11 @@ static int rtw_mp_QueryDrv(struct net_device *dev,
> if (!input)
> return -ENOMEM;
>
> - if (copy_from_user(input, wrqu->data.pointer, wrqu->data.length))
> - return -EFAULT;
> + if (copy_from_user(input, wrqu->data.pointer, wrqu->data.length)) {
> + kfree(input);
> + return -EFAULT;
> + }
> +
> DBG_88E("%s:iwpriv in =%s\n", __func__, input);
>
> qAutoLoad = strncmp(input, "autoload", 8); /* strncmp true is 0 */
> --
> 2.25.1
>
>

Again, what tree are you making this patch against? This function is no
longer present.

Also, when sending more than one patch for the same driver, always make
a patch series so we know what order they should be applied in.

thanks,

greg k-h