Re: [PATCH] wifi: brcmfmac: Adjust n_channels usage for __counted_by

[Kalle Valo]

Arend Van Spriel <aspriel@xxxxxxxxx> writes:

> 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.

Thanks.

> Cc: to stable?

Is commit e3eac9f32ec0 in stable releases? (I don't follow stable and
don't know what commits they take.) I propose that as we have Fixes tag
let's not add cc but instead let stable maintainers to decide.

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