Re: [PATCH 1/1] brcmfmac: fix pmksa->bssid usage

From: Nicolas Iooss
Date: Mon Aug 22 2016 - 09:04:08 EST


Hello,

After I sent the following patch a few weeks ago, I have not received
any feedback. Could you please review it and tell me what I may have
done wrong?

Thanks,
Nicolas

On 05/08/16 22:34, Nicolas Iooss wrote:
> The struct cfg80211_pmksa defines its bssid field as:
>
> const u8 *bssid;
>
> contrary to struct brcmf_pmksa, which uses:
>
> u8 bssid[ETH_ALEN];
>
> Therefore in brcmf_cfg80211_del_pmksa(), &pmksa->bssid takes the address
> of this field (of type u8**), not the one of its content (which would be
> u8*). Remove the & operator to make brcmf_dbg("%pM") and memcmp()
> behave as expected.
>
> This bug have been found using a custom static checker (which checks the
> usage of %p... attributes at build time). It has been introduced in
> commit 6c404f34f2bd ("brcmfmac: Cleanup pmksa cache handling code"),
> which replaced pmksa->bssid by &pmksa->bssid while refactoring the code,
> without modifying struct cfg80211_pmksa definition.
>
> Fixes: 6c404f34f2bd ("brcmfmac: Cleanup pmksa cache handling code")
> Cc: stable@xxxxxxxxxxxxxx
> Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@xxxxxxx>
> ---
>
> scripts/checkpatch.pl reports a warning: "Prefer ether_addr_equal() or
> ether_addr_equal_unaligned() over memcmp()". Because some files in
> drivers/net/wireless/broadcom/brcm80211/brcmfmac/ still use memcmp()
> to compare addresses and because I do not know whether pmksa->bssid is
> always aligned, I did not follow this warning.
>
> drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> index 2628d5e12c64..aceab77cd95a 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> @@ -3884,11 +3884,11 @@ brcmf_cfg80211_del_pmksa(struct wiphy *wiphy, struct net_device *ndev,
> if (!check_vif_up(ifp->vif))
> return -EIO;
>
> - brcmf_dbg(CONN, "del_pmksa - PMK bssid = %pM\n", &pmksa->bssid);
> + brcmf_dbg(CONN, "del_pmksa - PMK bssid = %pM\n", pmksa->bssid);
>
> npmk = le32_to_cpu(cfg->pmk_list.npmk);
> for (i = 0; i < npmk; i++)
> - if (!memcmp(&pmksa->bssid, &pmk[i].bssid, ETH_ALEN))
> + if (!memcmp(pmksa->bssid, &pmk[i].bssid, ETH_ALEN))
> break;
>
> if ((npmk > 0) && (i < npmk)) {
>