On 9/30/19 4:18 PM, David Laight wrote:
From: Denis Efremov
Sent: 30 September 2019 12:02 memcpy() in phy_ConfigBBWithParaFile() and PHY_ConfigRFWithParaFile() is called with "src == NULL && len == 0". This is an undefined behavior.
I'm pretty certain it is well defined (to do nothing).
Moreover this if pre-condition "pBufLen && (*pBufLen == 0) && !pBuf" is constantly false because it is a nested if in the else brach, i.e., "if (cond) { ... } else { if (cond) {...} }". This patch alters the if condition to check "pBufLen && pBuf" pointers are not NULL.
...
Not tested. I don't have the hardware. The fix is based on my guess.
drivers/staging/rtl8723bs/hal/hal_com_phycfg.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/rtl8723bs/hal/hal_com_phycfg.c b/drivers/staging/rtl8723bs/hal/hal_com_phycfg.c index 6539bee9b5ba..0902dc3c1825 100644 --- a/drivers/staging/rtl8723bs/hal/hal_com_phycfg.c +++ b/drivers/staging/rtl8723bs/hal/hal_com_phycfg.c @@ -2320,7 +2320,7 @@ int phy_ConfigBBWithParaFile( } } } else {
if (pBufLen && (*pBufLen == 0) && !pBuf) {
if (pBufLen && pBuf) { memcpy(pHalData->para_file_buf, pBuf, *pBufLen);The existing code is clearly garbage. It only ever does memcpy(tgt, NULL, 0).
Under the assumption that the code has been tested the copy clearly isn't needed at all and can be deleted completely!
Initially I also thought that this is just a dead code and it could be simply removed. However, if we look at it more carefully, this if condition looks like a copy-paste error:
if (pBufLen && (*pBufLen == 0) && !pBuf) { // get proper len // allocate pBuf ... memcpy(pBuf, pHalData->para_file_buf, rlen); ... } else { if (pBufLen && (*pBufLen == 0) && !pBuf) { // <== condition in patch memcpy(pHalData->para_file_buf, pBuf, *pBufLen); rtStatus = _SUCCESS; } else DBG_871X("%s(): Critical Error !!!\n", __func__); }
Thus, I think it will be incorrect to delete the second memcpy.
OTOH if the code hasn't been tested maybe the entire source file should be removed :-)
David
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