Re: [PATCH v2] staging: rtl8723bs: initialize le_tmp64 in rtw_BIP_verify()

[Dan Carpenter <dan.carpenter@linaro.org>]

On Fri, Mar 20, 2026 at 06:29:13PM +0100, Greg KH wrote:
> On Sat, Mar 21, 2026 at 01:25:02AM +0800, Lin YuChen wrote:
> > Initialize le_tmp64 to zero in rtw_BIP_verify() to prevent using
> > uninitialized data.
> > 
> > Smatch warns that only 6 bytes are copied to this 8-byte (u64)
> > variable, leaving the last two bytes uninitialized:
> > 
> > drivers/staging/rtl8723bs/core/rtw_security.c:1308 rtw_BIP_verify()
> > warn: not copying enough bytes for '&le_tmp64' (8 vs 6 bytes)
> > 
> > Initializing the variable at the start of the function fixes this
> > warning and ensures predictable behavior.
> 
> Which makes me wonder how this ever worked at all, if random data was in
> those 2 bytes.

These days, everyone sane zeroes their stack variables, but this driver
is older than the zeroing code so it's a puzzling thing.

I could imagine a couple different ways that the code might be able to
work even with uninitialized data...  It wouldn't surprise me if the
check for:

	/* BIP packet number should bigger than previous BIP packet */

is some kind of work around for bug?

regards,
dan carpenter