On Mon, Jun 22, 2020 at 10:04:18AM -0700, Nick Desaulniers wrote: > On Fri, Jun 19, 2020 at 8:30 PM Kees Cook <keesc...@chromium.org> wrote: > > > > Using uninitialized_var() is dangerous as it papers over real bugs[1] > > (or can in the future), and suppresses unrelated compiler warnings (e.g. > > "unused variable"). If the compiler thinks it is uninitialized, either > > simply initialize the variable or make compiler changes. As a precursor > > to removing[2] this[3] macro[4], just initialize this variable to NULL. > > No later NULL deref is possible due to the early returns outside of the > > (phy->rev >= 7 && phy->rev < 19) case, which explicitly tests for NULL. > > > > [1] https://lore.kernel.org/lkml/20200603174714.192027-1-gli...@google.com/ > > [2] > > https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1tgqcr5vqkczwj0qxk6cernou6eedsuda...@mail.gmail.com/ > > [3] > > https://lore.kernel.org/lkml/ca+55afwgbgqhbp1fkxvrkepzyr5j8n1vkt1vzdz9knmpuxh...@mail.gmail.com/ > > [4] > > https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yvju65tplgn_ybynv0ve...@mail.gmail.com/ > > > > Fixes: 58619b14d106 ("b43: move under broadcom vendor directory") > > Signed-off-by: Kees Cook <keesc...@chromium.org> > > I see three total uses of uninitialized_var() in this file, do we want > to eliminate all of them?
This is the only one that needed an explicit initialization -- all the others are handled in the treewide patch. I *could* split it out here, but I found it easier to keep the "no op" changes together in the treewide patch. -Kees > > > --- > > drivers/net/wireless/broadcom/b43/phy_n.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/net/wireless/broadcom/b43/phy_n.c > > b/drivers/net/wireless/broadcom/b43/phy_n.c > > index c33b4235839d..46db91846007 100644 > > --- a/drivers/net/wireless/broadcom/b43/phy_n.c > > +++ b/drivers/net/wireless/broadcom/b43/phy_n.c > > @@ -4222,7 +4222,7 @@ static void b43_nphy_tx_gain_table_upload(struct > > b43_wldev *dev) > > u32 rfpwr_offset; > > u8 pga_gain, pad_gain; > > int i; > > - const s16 *uninitialized_var(rf_pwr_offset_table); > > + const s16 *rf_pwr_offset_table = NULL; > > > > table = b43_nphy_get_tx_gain_table(dev); > > if (!table) > > -- > > -- > Thanks, > ~Nick Desaulniers -- Kees Cook
