Re: [PATCH 1/5] staging: r8188eu: Remove wrappers for kalloc() and kzalloc()

From: Dan Carpenter
Date: Fri Aug 06 2021 - 07:08:23 EST


On Thu, Aug 05, 2021 at 01:37:13PM -0500, Larry Finger wrote:
> diff --git a/drivers/staging/r8188eu/core/rtw_cmd.c b/drivers/staging/r8188eu/core/rtw_cmd.c
> index 4ac76ca6e383..d7d33e201f37 100644
> --- a/drivers/staging/r8188eu/core/rtw_cmd.c
> +++ b/drivers/staging/r8188eu/core/rtw_cmd.c
> @@ -1947,10 +1947,13 @@ static void c2h_wk_callback(struct work_struct *work)
> if ((c2h_evt = (struct c2h_evt_hdr *)rtw_cbuf_pop(evtpriv->c2h_queue)) != NULL) {
> /* This C2H event is read, clear it */
> c2h_evt_clear(adapter);
> - } else if ((c2h_evt = (struct c2h_evt_hdr *)rtw_malloc(16)) != NULL) {
> - /* This C2H event is not read, read & clear now */
> - if (c2h_evt_read(adapter, (u8 *)c2h_evt) != _SUCCESS)
> - continue;
> + } else {
> + c2h_evt = kmalloc(16, GFP_KERNEL);
> + if (c2h_evt) {
> + /* This C2H event is not read, read & clear now */
> + if (c2h_evt_read(adapter, (u8 *)c2h_evt) != _SUCCESS)
> + continue;

Not related to your patch (don't resend, please fix this in a follow on
patch if you want to) but this isn't correct. If the allocation fails,
it leads to a NULL dereference. Or if the c2h_evt_read() call fails
there needs to be a kfree(c2h_evt) before the continue.

> + }
> }
>

regards,
dan carpenter