2022-04-06 16:56:41

by Xiaoke Wang

[permalink] [raw]
Subject: [PATCH v4] staging: r8188eu: 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 not be properly
released. Besides, considering there are only two error paths and the
first one can directly return, we do not need to implicitly jump to the
`exit` tag to execute the error handling code.

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().

Signed-off-by: Xiaoke Wang <[email protected]>
---
ChangeLog:
v1->v2: simplify the function.
v2->v3: rebase and recover some whitespace cleanups.
v3->v4: update the description.
drivers/staging/r8188eu/core/rtw_cmd.c | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/r8188eu/core/rtw_cmd.c b/drivers/staging/r8188eu/core/rtw_cmd.c
index 4eeb961..f6653d6 100644
--- a/drivers/staging/r8188eu/core/rtw_cmd.c
+++ b/drivers/staging/r8188eu/core/rtw_cmd.c
@@ -18,8 +18,6 @@ No irqsave is necessary.

static int _rtw_init_cmd_priv(struct cmd_priv *pcmdpriv)
{
- int res = _SUCCESS;
-
init_completion(&pcmdpriv->enqueue_cmd);
/* sema_init(&(pcmdpriv->cmd_done_sema), 0); */
init_completion(&pcmdpriv->start_cmd_thread);
@@ -34,27 +32,24 @@ static int _rtw_init_cmd_priv(struct cmd_priv *pcmdpriv)
pcmdpriv->cmd_allocated_buf = kzalloc(MAX_CMDSZ + CMDBUFF_ALIGN_SZ,
GFP_KERNEL);

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

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

pcmdpriv->rsp_allocated_buf = kzalloc(MAX_RSPSZ + 4, GFP_KERNEL);

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

pcmdpriv->rsp_buf = pcmdpriv->rsp_allocated_buf + 4 - ((size_t)(pcmdpriv->rsp_allocated_buf) & 3);

pcmdpriv->cmd_done_cnt = 0;
pcmdpriv->rsp_cnt = 0;
-exit:

- return res;
+ return _SUCCESS;
}

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