On Tue, Aug 31, 2021 at 01:03:55AM +0530, F.A.Sulaiman wrote:
> Smatch reported memory leak bug in rtl8723b_FirmwareDownload function.
> The problem is pFirmware memory is not released in release_fw1.
> Instead of redirecting to release_fw1 we can turn it into exit
> and free the memory.
>
> Signed-off-by: F.A. SULAIMAN <asha...@itfac.mrt.ac.lk>
> ---
> drivers/staging/rtl8723bs/hal/rtl8723b_hal_init.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/staging/rtl8723bs/hal/rtl8723b_hal_init.c
> b/drivers/staging/rtl8723bs/hal/rtl8723b_hal_init.c
> index de8caa6cd418..b59c2aa3a9d8 100644
> --- a/drivers/staging/rtl8723bs/hal/rtl8723b_hal_init.c
> +++ b/drivers/staging/rtl8723bs/hal/rtl8723b_hal_init.c
> @@ -436,7 +436,7 @@ s32 rtl8723b_FirmwareDownload(struct adapter *padapter,
> bool bUsedWoWLANFw)
> if (pFirmware->fw_length > FW_8723B_SIZE) {
> rtStatus = _FAIL;
> DBG_871X_LEVEL(_drv_emerg_, "Firmware size:%u exceed %u\n",
> pFirmware->fw_length, FW_8723B_SIZE);
> - goto release_fw1;
> + goto exit;
> }
The current tree doesn't have DBG_871X_LEVEL() so you must be working
against something old. You need to work against linux-next or staging
next.
Your patch fixes a bug, but it would be better to just re-write the
error handling for this function. There is another bug that a bunch
of error paths don't call release_firmware(fw). Use the "Free the Last
Thing" method.
pFirmware = kzalloc(sizeof(struct rt_firmware), GFP_KERNEL);
if (!pFirmware)
return _FAIL;
The last thing we allocated is "pFirmware" so free that if we have an
error.
pBTFirmware = kzalloc(sizeof(struct rt_firmware), GFP_KERNEL);
if (!pBTFirmware) {
rtStatus = _FAIL;
goto free_firmware;
}
Now the last thing is pBTFirmware.
rtStatus = request_firmware(&fw, fwfilepath, device);
if (rtStatus) {
rtStatus = _FAIL;
goto free_bt_firmware;
}
Now the last thing is "fw". But this is a bit tricky because we're
going to release it as soon as possible and not wait until the end of
the function. There isn't a reason for this... We can change that or
keep it as-is. If we keep it as is, then the we'll just call
release_firmware(fw); before the goto free_bt_firmware; The current
code leaks fw on a bunch of error paths.
pFirmware->fw_buffer_sz = kmemdup(fw->data, fw->size, GFP_KERNEL);
if (!pFirmware->fw_buffer_sz) {
rtStatus = _FAIL;
release_firmware(fw);
goto free_bt_firmware;
}
Or:
pFirmware->fw_buffer_sz = kmemdup(fw->data, fw->size, GFP_KERNEL);
if (!pFirmware->fw_buffer_sz) {
rtStatus = _FAIL;
goto release_fw;
}
Now the last thing is pFirmware->fw_buffer_sz. Etc.
Then at the end it's just:
free_fw_buffer:
kfree(pFirmware->fw_buffer_sz);
release_fw:
release_firmware(fw);
free_bt_firmware:
kfree(pBTFirmware);
free_firmware:
kfree(pFirmware);
return rtStatus;
}
regards,
dan carpenter
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