6.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kees Cook <keescook@xxxxxxxxxxxx> [ 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 <aspriel@xxxxxxxxx> Cc: Franky Lin <franky.lin@xxxxxxxxxxxx> Cc: Hante Meuleman <hante.meuleman@xxxxxxxxxxxx> Cc: Kalle Valo <kvalo@xxxxxxxxxx> Cc: Chi-hsien Lin <chi-hsien.lin@xxxxxxxxxxxx> Cc: Ian Lin <ian.lin@xxxxxxxxxxxx> Cc: Johannes Berg <johannes.berg@xxxxxxxxx> Cc: Wright Feng <wright.feng@xxxxxxxxxxx> Cc: Hector Martin <marcan@xxxxxxxxx> Cc: linux-wireless@xxxxxxxxxxxxxxx Cc: brcm80211-dev-list.pdl@xxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx> Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx> Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx> Link: https://msgid.link/20240126223150.work.548-kees@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 667462369a32..44cea18dd20e 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c @@ -3779,8 +3779,10 @@ 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 && -- 2.43.0