Thread (2 messages) 2 messages, 2 authors, 2021-12-09

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

From: Greg KH <gregkh@linuxfoundation.org>
Date: 2021-12-09 08:00:06
Also in: lkml

On Thu, Dec 09, 2021 at 03:34:21PM +0800, Jianglei Nie wrote:
quoted hunk ↗ jump to hunk
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 <redacted>
---
 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
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