2022-09-08 08:00:25

by Xiaoke Wang

Subject: [PATCH v3] staging: rtl8723bs: fix a potential memory leak in rtw_init_cmd_priv()

From: Xiaoke Wang <[email protected]>

In rtw_init_cmd_priv(), if `pcmdpriv->rsp_allocated_buf` is allocated
in failure, then `pcmdpriv->cmd_allocated_buf` will be not properly
released. Besides, considering there are only two error paths and the
first one can directly return, so we do not need implicitly jump to the
`exit` tag to execute the error handler.

So this patch added `kfree(pcmdpriv->cmd_allocated_buf);` on the error
path to release the resource and simplified the return logic of
rtw_init_cmd_priv(). As there is no FooBar device to test with, no runtime
testing was performed.

Signed-off-by: Xiaoke Wang <[email protected]>
---
ChangeLog:
v1->v2 update the description.
v2->v3 update the description.
drivers/staging/rtl8723bs/core/rtw_cmd.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/rtl8723bs/core/rtw_cmd.c b/drivers/staging/rtl8723bs/core/rtw_cmd.c
index e574893..9126ea9 100644
--- a/drivers/staging/rtl8723bs/core/rtw_cmd.c
+++ b/drivers/staging/rtl8723bs/core/rtw_cmd.c
@@ -161,8 +161,6 @@ static struct cmd_hdl wlancmds[] = {

int rtw_init_cmd_priv(struct cmd_priv *pcmdpriv)
{
- int res = 0;
-
init_completion(&pcmdpriv->cmd_queue_comp);
init_completion(&pcmdpriv->terminate_cmdthread_comp);

@@ -175,18 +173,17 @@ int rtw_init_cmd_priv(struct cmd_priv *pcmdpriv)

pcmdpriv->cmd_allocated_buf = rtw_zmalloc(MAX_CMDSZ + CMDBUFF_ALIGN_SZ);

- if (!pcmdpriv->cmd_allocated_buf) {
- res = -ENOMEM;
- goto exit;
- }
+ if (!pcmdpriv->cmd_allocated_buf)
+ return -ENOMEM;

pcmdpriv->cmd_buf = pcmdpriv->cmd_allocated_buf + CMDBUFF_ALIGN_SZ - ((SIZE_PTR)(pcmdpriv->cmd_allocated_buf) & (CMDBUFF_ALIGN_SZ-1));

pcmdpriv->rsp_allocated_buf = rtw_zmalloc(MAX_RSPSZ + 4);

if (!pcmdpriv->rsp_allocated_buf) {
- res = -ENOMEM;
- goto exit;
+ kfree(pcmdpriv->cmd_allocated_buf);
+ pcmdpriv->cmd_allocated_buf = NULL;
+ return -ENOMEM;
}

pcmdpriv->rsp_buf = pcmdpriv->rsp_allocated_buf + 4 - ((SIZE_PTR)(pcmdpriv->rsp_allocated_buf) & 3);
@@ -196,8 +193,8 @@ int rtw_init_cmd_priv(struct cmd_priv *pcmdpriv)
pcmdpriv->rsp_cnt = 0;

mutex_init(&pcmdpriv->sctx_mutex);
-exit:
- return res;
+
+ return 0;
}

static void c2h_wk_callback(struct work_struct *work);
--

2022-09-09 08:34:54

by Greg Kroah-Hartman

Subject: Re: [PATCH v3] staging: rtl8723bs: fix a potential memory leak in rtw_init_cmd_priv()

On Thu, Sep 08, 2022 at 03:33:00PM +0800, [email protected] wrote:
> From: Xiaoke Wang <[email protected]>
>
> In rtw_init_cmd_priv(), if `pcmdpriv->rsp_allocated_buf` is allocated
> in failure, then `pcmdpriv->cmd_allocated_buf` will be not properly
> released. Besides, considering there are only two error paths and the
> first one can directly return, so we do not need implicitly jump to the
> `exit` tag to execute the error handler.
>
> So this patch added `kfree(pcmdpriv->cmd_allocated_buf);` on the error
> path to release the resource and simplified the return logic of

Again, whitespace at end of changelog text :(

> rtw_init_cmd_priv(). As there is no FooBar device to test with, no runtime
> testing was performed.

"FooBar"?

>
> Signed-off-by: Xiaoke Wang <[email protected]>
> ---
> ChangeLog:
> v1->v2 update the description.
> v2->v3 update the description.
> drivers/staging/rtl8723bs/core/rtw_cmd.c | 17 +++++++----------
> 1 file changed, 7 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/staging/rtl8723bs/core/rtw_cmd.c b/drivers/staging/rtl8723bs/core/rtw_cmd.c
> index e574893..9126ea9 100644
> --- a/drivers/staging/rtl8723bs/core/rtw_cmd.c
> +++ b/drivers/staging/rtl8723bs/core/rtw_cmd.c
> @@ -161,8 +161,6 @@ static struct cmd_hdl wlancmds[] = {
>
> int rtw_init_cmd_priv(struct cmd_priv *pcmdpriv)
> {
> - int res = 0;
> -
> init_completion(&pcmdpriv->cmd_queue_comp);
> init_completion(&pcmdpriv->terminate_cmdthread_comp);
>
> @@ -175,18 +173,17 @@ int rtw_init_cmd_priv(struct cmd_priv *pcmdpriv)
>
> pcmdpriv->cmd_allocated_buf = rtw_zmalloc(MAX_CMDSZ + CMDBUFF_ALIGN_SZ);
>
> - if (!pcmdpriv->cmd_allocated_buf) {
> - res = -ENOMEM;
> - goto exit;
> - }
> + if (!pcmdpriv->cmd_allocated_buf)
> + return -ENOMEM;
>
> pcmdpriv->cmd_buf = pcmdpriv->cmd_allocated_buf + CMDBUFF_ALIGN_SZ - ((SIZE_PTR)(pcmdpriv->cmd_allocated_buf) & (CMDBUFF_ALIGN_SZ-1));
>
> pcmdpriv->rsp_allocated_buf = rtw_zmalloc(MAX_RSPSZ + 4);
>
> if (!pcmdpriv->rsp_allocated_buf) {
> - res = -ENOMEM;
> - goto exit;
> + kfree(pcmdpriv->cmd_allocated_buf);
> + pcmdpriv->cmd_allocated_buf = NULL;

Why does this have to be set to NULL?

thanks,

greg k-h