Re: [PATCH] wifi: brcmfmac: Adjust n_channels usage for __counted_by
From: Arend Van Spriel
Date: Fri Feb 02 2024 - 05:01:35 EST
On 2/2/2024 10:58 AM, Arend Van Spriel wrote:
On 2/1/2024 11:04 AM, Kalle Valo wrote:
Kees Cook <keescook@xxxxxxxxxxxx> wrote:
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>
I'm planning to queue this for wireless tree. Arend, ack?
This slipped past my broadcom email. As the Fixes commit is in 6.7 I
would say ACK.
Cc: to stable?
Gr. AvS