Patch "wifi: ath9k: work around memset overflow warning" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    wifi: ath9k: work around memset overflow warning

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     wifi-ath9k-work-around-memset-overflow-warning.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit c8f1eb0f52624366d065fc9d7b77af77d329a440
Author: Arnd Bergmann <arnd@xxxxxxxx>
Date:   Thu Apr 4 09:35:59 2024 +0300

    wifi: ath9k: work around memset overflow warning
    
    [ Upstream commit 61752ac69b69ed2e04444d090f6917c77ab36d42 ]
    
    gcc-9 and some other older versions produce a false-positive warning
    for zeroing two fields
    
    In file included from include/linux/string.h:369,
                     from drivers/net/wireless/ath/ath9k/main.c:18:
    In function 'fortify_memset_chk',
        inlined from 'ath9k_ps_wakeup' at drivers/net/wireless/ath/ath9k/main.c:140:3:
    include/linux/fortify-string.h:462:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
      462 |                         __write_overflow_field(p_size_field, size);
          |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    
    Using a struct_group seems to reliably avoid the warning and
    not make the code much uglier. The combined memset() should even
    save a couple of cpu cycles.
    
    Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
    Acked-by: Toke Høiland-Jørgensen <toke@xxxxxxx>
    Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
    Signed-off-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx>
    Link: https://msgid.link/20240328135509.3755090-3-arnd@xxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/wireless/ath/ath.h b/drivers/net/wireless/ath/ath.h
index f02a308a9ffc5..34654f710d8a1 100644
--- a/drivers/net/wireless/ath/ath.h
+++ b/drivers/net/wireless/ath/ath.h
@@ -171,8 +171,10 @@ struct ath_common {
 	unsigned int clockrate;
 
 	spinlock_t cc_lock;
-	struct ath_cycle_counters cc_ani;
-	struct ath_cycle_counters cc_survey;
+	struct_group(cc,
+		struct ath_cycle_counters cc_ani;
+		struct ath_cycle_counters cc_survey;
+	);
 
 	struct ath_regulatory regulatory;
 	struct ath_regulatory reg_world_copy;
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 1494feedb27db..aa271b82875e0 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -135,8 +135,7 @@ void ath9k_ps_wakeup(struct ath_softc *sc)
 	if (power_mode != ATH9K_PM_AWAKE) {
 		spin_lock(&common->cc_lock);
 		ath_hw_cycle_counters_update(common);
-		memset(&common->cc_survey, 0, sizeof(common->cc_survey));
-		memset(&common->cc_ani, 0, sizeof(common->cc_ani));
+		memset(&common->cc, 0, sizeof(common->cc));
 		spin_unlock(&common->cc_lock);
 	}