From 4571767d66d62eb0d4ffda0a42a42c84eefb38c3 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 26 Jan 2024 14:31:53 -0800 Subject: [PATCH] wifi: brcmfmac: Adjust n_channels usage for __counted_by [ Upstream commit 5bdda0048c8d1bbe2019513b2d6200cc0d09c7bd ] After commit e3eac9f32ec0 ("wifi: cfg80211: Annotate struct cfg80211_scan_request with __counted_by"), the compiler may enforce dynamic array indexing of req->channels to stay below n_channels. As a result, n_channels needs to be increased _before_ accessing the newly added array index. Increment it first, then use "i" for the prior index. Solves this warning in the coming GCC that has __counted_by support: ../drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c: In function 'brcmf_internal_escan_add_info': ../drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c:3783:46: warning: operation on 'req-> n_channels' may be undefined [-Wsequence-point] 3783 | req->channels[req->n_channels++] = chan; | ~~~~~~~~~~~~~~~^~ Fixes: e3eac9f32ec0 ("wifi: cfg80211: Annotate struct cfg80211_scan_request with __counted_by") Cc: Arend van Spriel Cc: Franky Lin Cc: Hante Meuleman Cc: Kalle Valo Cc: Chi-hsien Lin Cc: Ian Lin Cc: Johannes Berg Cc: Wright Feng Cc: Hector Martin Cc: linux-wireless@vger.kernel.org Cc: brcm80211-dev-list.pdl@broadcom.com Signed-off-by: Kees Cook Reviewed-by: Hans de Goede Reviewed-by: Linus Walleij Reviewed-by: Gustavo A. R. Silva Signed-off-by: Kalle Valo Link: https://msgid.link/20240126223150.work.548-kees@kernel.org Signed-off-by: Sasha Levin --- drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c index 2a90bb2..6049f9a 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c @@ -3780,8 +3780,10 @@ static int brcmf_internal_escan_add_info(struct cfg80211_scan_request *req, if (req->channels[i] == chan) break; } - if (i == req->n_channels) - req->channels[req->n_channels++] = chan; + if (i == req->n_channels) { + req->n_channels++; + req->channels[i] = chan; + } for (i = 0; i < req->n_ssids; i++) { if (req->ssids[i].ssid_len == ssid_len && -- 2.7.4