net/mac80211/cfg.c | 38 ++++++++++++++++++++++++++++++++++---- 1 file changed, 34 insertions(+), 4 deletions(-)
Commit 78a7a126dc5b ("wifi: mac80211: validate SCAN_FLAG_AP in scan request
during MLO") introduced a check that rejects scan requests if any link is
already beaconing. This works fine when all links share the same radio, but
breaks down in multi-radio setups.
Consider a scenario where a 2.4 GHz link is beaconing and a scan is
requested on a 5 GHz link, each backed by a different physical radio. The
current logic still blocks the scan, even though it should be allowed. As a
result, interface bring-up fails unnecessarily in valid configurations.
Fix this by checking whether the scan is being requested on the same
underlying radio as the beaconing link. Only reject the scan if it targets
a link that is already beaconing and the SCAN_FLAG_AP is not set. This
ensures correct behavior in multi-radio environments and avoids false
rejections.
Fixes: 78a7a126dc5b ("wifi: mac80211: validate SCAN_FLAG_AP in scan request during MLO")
Signed-off-by: Aditya Kumar Singh <aditya.kumar.singh@oss.qualcomm.com>
---
Depends-on: https://lore.kernel.org/all/20250527-mlo-dfs-acs-v2-0-92c2f37c81d9@quicinc.com/
---
net/mac80211/cfg.c | 38 ++++++++++++++++++++++++++++++++++----
1 file changed, 34 insertions(+), 4 deletions(-)
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index d9d88f2f283120ba366401d3ac546e59d8c61c21..22bbe1f4bfc3e2248e6c376c8a465da924180e0f 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2897,6 +2897,10 @@ static int ieee80211_scan(struct wiphy *wiphy,
struct cfg80211_scan_request *req)
{
struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_link_data *link;
+ struct ieee80211_channel *chan;
+ int radio_idx;
+ u8 link_id;
sdata = IEEE80211_WDEV_TO_SUB_IF(req->wdev);
@@ -2924,10 +2928,36 @@ static int ieee80211_scan(struct wiphy *wiphy,
* the frames sent while scanning on other channel will be
* lost)
*/
- if (ieee80211_num_beaconing_links(sdata) &&
- (!(wiphy->features & NL80211_FEATURE_AP_SCAN) ||
- !(req->flags & NL80211_SCAN_FLAG_AP)))
- return -EOPNOTSUPP;
+ for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS;
+ link_id++) {
+ link = sdata_dereference(sdata->link[link_id], sdata);
+ if (!link)
+ continue;
+
+ /* if the link is not beaconing, ignore it */
+ if (!sdata_dereference(link->u.ap.beacon, sdata))
+ continue;
+
+ /* If we are here then at least one of the link is
+ * beaconing and since radio level information is
+ * not present or single underlying radio is present,
+ * no point in checking further and hence return if
+ * flag requirements are not met.
+ */
+ if (wiphy->n_radio < 2 &&
+ (!(wiphy->features & NL80211_FEATURE_AP_SCAN) ||
+ !(req->flags & NL80211_SCAN_FLAG_AP)))
+ return -EOPNOTSUPP;
+
+ chan = link->conf->chanreq.oper.chan;
+ radio_idx = cfg80211_get_radio_idx_by_chan(wiphy, chan);
+
+ if (ieee80211_is_radio_idx_in_scan_req(wiphy, req,
+ radio_idx) &&
+ (!(wiphy->features & NL80211_FEATURE_AP_SCAN) ||
+ !(req->flags & NL80211_SCAN_FLAG_AP)))
+ return -EOPNOTSUPP;
+ }
break;
case NL80211_IFTYPE_NAN:
default:
---
base-commit: ea15e046263b19e91ffd827645ae5dfa44ebd044
change-id: 20250527-fix_scan_ap_flag_requirement_during_mlo-d9bce1b859a1Hi Aditya,
kernel test robot noticed the following build errors:
[auto build test ERROR on ea15e046263b19e91ffd827645ae5dfa44ebd044]
url: https://github.com/intel-lab-lkp/linux/commits/Aditya-Kumar-Singh/wifi-mac80211-consider-links-for-validating-SCAN_FLAG_AP-in-scan-request-during-MLO/20250528-113350
base: ea15e046263b19e91ffd827645ae5dfa44ebd044
patch link: https://lore.kernel.org/r/20250528-fix_scan_ap_flag_requirement_during_mlo-v1-1-35ac0e3a2f7b%40oss.qualcomm.com
patch subject: [PATCH wireless-next] wifi: mac80211: consider links for validating SCAN_FLAG_AP in scan request during MLO
config: arm-randconfig-003-20250528 (https://download.01.org/0day-ci/archive/20250528/202505281853.CBjCB3yV-lkp@intel.com/config)
compiler: clang version 19.1.7 (https://github.com/llvm/llvm-project cd708029e0b2869e80abe31ddb175f7c35361f90)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250528/202505281853.CBjCB3yV-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202505281853.CBjCB3yV-lkp@intel.com/
All errors (new ones prefixed by >>):
>> net/mac80211/cfg.c:2953:16: error: call to undeclared function 'cfg80211_get_radio_idx_by_chan'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
2953 | radio_idx = cfg80211_get_radio_idx_by_chan(wiphy, chan);
| ^
>> net/mac80211/cfg.c:2955:8: error: call to undeclared function 'ieee80211_is_radio_idx_in_scan_req'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
2955 | if (ieee80211_is_radio_idx_in_scan_req(wiphy, req,
| ^
2 errors generated.
vim +/cfg80211_get_radio_idx_by_chan +2953 net/mac80211/cfg.c
2895
2896 static int ieee80211_scan(struct wiphy *wiphy,
2897 struct cfg80211_scan_request *req)
2898 {
2899 struct ieee80211_sub_if_data *sdata;
2900 struct ieee80211_link_data *link;
2901 struct ieee80211_channel *chan;
2902 int radio_idx;
2903 u8 link_id;
2904
2905 sdata = IEEE80211_WDEV_TO_SUB_IF(req->wdev);
2906
2907 switch (ieee80211_vif_type_p2p(&sdata->vif)) {
2908 case NL80211_IFTYPE_STATION:
2909 case NL80211_IFTYPE_ADHOC:
2910 case NL80211_IFTYPE_MESH_POINT:
2911 case NL80211_IFTYPE_P2P_CLIENT:
2912 case NL80211_IFTYPE_P2P_DEVICE:
2913 break;
2914 case NL80211_IFTYPE_P2P_GO:
2915 if (sdata->local->ops->hw_scan)
2916 break;
2917 /*
2918 * FIXME: implement NoA while scanning in software,
2919 * for now fall through to allow scanning only when
2920 * beaconing hasn't been configured yet
2921 */
2922 fallthrough;
2923 case NL80211_IFTYPE_AP:
2924 /*
2925 * If the scan has been forced (and the driver supports
2926 * forcing), don't care about being beaconing already.
2927 * This will create problems to the attached stations (e.g. all
2928 * the frames sent while scanning on other channel will be
2929 * lost)
2930 */
2931 for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS;
2932 link_id++) {
2933 link = sdata_dereference(sdata->link[link_id], sdata);
2934 if (!link)
2935 continue;
2936
2937 /* if the link is not beaconing, ignore it */
2938 if (!sdata_dereference(link->u.ap.beacon, sdata))
2939 continue;
2940
2941 /* If we are here then at least one of the link is
2942 * beaconing and since radio level information is
2943 * not present or single underlying radio is present,
2944 * no point in checking further and hence return if
2945 * flag requirements are not met.
2946 */
2947 if (wiphy->n_radio < 2 &&
2948 (!(wiphy->features & NL80211_FEATURE_AP_SCAN) ||
2949 !(req->flags & NL80211_SCAN_FLAG_AP)))
2950 return -EOPNOTSUPP;
2951
2952 chan = link->conf->chanreq.oper.chan;
> 2953 radio_idx = cfg80211_get_radio_idx_by_chan(wiphy, chan);
2954
> 2955 if (ieee80211_is_radio_idx_in_scan_req(wiphy, req,
2956 radio_idx) &&
2957 (!(wiphy->features & NL80211_FEATURE_AP_SCAN) ||
2958 !(req->flags & NL80211_SCAN_FLAG_AP)))
2959 return -EOPNOTSUPP;
2960 }
2961 break;
2962 case NL80211_IFTYPE_NAN:
2963 default:
2964 return -EOPNOTSUPP;
2965 }
2966
2967 return ieee80211_request_scan(sdata, req);
2968 }
2969
--
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