wifi: mac80211: skip BSS_CHANGED_TXPOWER for monitor interfaces

[PATCH wireless] wifi: mac80211: skip BSS_CHANGED_TXPOWER for monitor interfaces

Posted by Dhyan K Prajapati 10 hours ago

Monitor mode interfaces do not maintain a BSS context, since a commit in
July 2025 monitor interfaces with WANT_MONITOR_VIF began receiving link
change notification duing ieee80211_add_vitual_monitor(), when
ieee_assign_link_chanctx() assigns a channel context, it triggers
ieee80211_recalc_txpower() this sends a bss_info_changed callback
receive link->conf as the bss_conf prameter, in monitor mode it isn't
initialised leading to NULL pointer dereference in drivers like iwldvm,
as BSS_CHANGED_TXPOWER is not applicable for monitor mode we can just
skip it.

Fixes: c57e5b9819df ("wifi: mac80211: fix WARN_ON for monitor mode on some devices")
Tested-by: Dhyan K Prajapati <dhyan1902209@gmail.com>
Signed-off-by: Dhyan K Prajapati <dhyan19022009@gmail.com>
---
 net/mac80211/iface.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 515384ca2..47f6bef0e 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -76,8 +76,9 @@ bool __ieee80211_recalc_txpower(struct ieee80211_link_data *link)
 void ieee80211_recalc_txpower(struct ieee80211_link_data *link,
 			      bool update_bss)
 {
-	if (__ieee80211_recalc_txpower(link) ||
-	    (update_bss && ieee80211_sdata_running(link->sdata)))
+	if (link->sdata->vif.type != NL80211_IFTYPE_MONITOR &&
+	    (__ieee80211_recalc_txpower(link) ||
+	     (update_bss && ieee80211_sdata_running(link->sdata))))
 		ieee80211_link_info_change_notify(link->sdata, link,
 						  BSS_CHANGED_TXPOWER);
 }
-- 
2.43.0

Re: [PATCH wireless] wifi: mac80211: skip BSS_CHANGED_TXPOWER for monitor interfaces

Posted by Krzysztof Kozlowski 10 hours ago

On 07/02/2026 12:02, Dhyan K Prajapati wrote:
> Monitor mode interfaces do not maintain a BSS context, since a commit in
> July 2025 monitor interfaces with WANT_MONITOR_VIF began receiving link
> change notification duing ieee80211_add_vitual_monitor(), when
> ieee_assign_link_chanctx() assigns a channel context, it triggers
> ieee80211_recalc_txpower() this sends a bss_info_changed callback
> receive link->conf as the bss_conf prameter, in monitor mode it isn't
> initialised leading to NULL pointer dereference in drivers like iwldvm,
> as BSS_CHANGED_TXPOWER is not applicable for monitor mode we can just

Impossible to understand.

> skip it.
> 
> Fixes: c57e5b9819df ("wifi: mac80211: fix WARN_ON for monitor mode on some devices")
> Tested-by: Dhyan K Prajapati <dhyan1902209@gmail.com>

No, you are the same person.

Plus I do not believe that this is anything more than microslop AI.

You ignore people's feedback, do not respond to it, do not version your
patches (still!). Start reading and responding the feedback. Provide
proofs (e.g. by improving your contributions) that you actually read
what we asked.

Best regards,
Krzysztof