From 29cc798e7061e603843091af2f17b5b25009e7b8 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 5 Nov 2025 16:03:42 +0100 Subject: [PATCH] wifi: mac80211: make link iteration safe for 'break' The current link iteration macros for_each_sdata_link() and for_each_sdata_link_rcu() are various nested for loops, but because they iterate all sdata instances and then all links inside, using 'break' inside the iteration doesn't actually break out of the whole iteration. Make it work by tracking whether or not the inner iteration (over links) actually completed, if it broke out then given list_for_each_entry() it still iterates all sdata instances but won't go into them. Link: https://patch.msgid.link/20251105160431.c21956654fc0.I8d4739af061c44c57d172f19a15303a44ad1e596@changeid Signed-off-by: Johannes Berg --- net/mac80211/ieee80211_i.h | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 878c3b14aeb80..72e4f326946fa 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -1239,9 +1239,12 @@ struct ieee80211_sub_if_data *vif_to_sdata(struct ieee80211_vif *p) for (struct ieee80211_sub_if_data *___sdata = NULL; \ !___sdata; \ ___sdata = (void *)~0 /* always stop */) \ + for (int ___link_id = ARRAY_SIZE(___sdata->link); \ + ___link_id; ___link_id = 0 /* always stop */) \ list_for_each_entry(___sdata, &(_local)->interfaces, list) \ - if (ieee80211_sdata_running(___sdata)) \ - for (int ___link_id = 0; \ + if (___link_id == ARRAY_SIZE(___sdata->link) && \ + ieee80211_sdata_running(___sdata)) \ + for (___link_id = 0; \ ___link_id < ARRAY_SIZE(___sdata->link); \ ___link_id++) \ if ((_link = wiphy_dereference((_local)->hw.wiphy, \ @@ -1255,9 +1258,12 @@ struct ieee80211_sub_if_data *vif_to_sdata(struct ieee80211_vif *p) for (struct ieee80211_sub_if_data *___sdata = NULL; \ !___sdata; \ ___sdata = (void *)~0 /* always stop */) \ - list_for_each_entry_rcu(___sdata, &(_local)->interfaces, list) \ - if (ieee80211_sdata_running(___sdata)) \ - for (int ___link_id = 0; \ + for (int ___link_id = ARRAY_SIZE(___sdata->link); \ + ___link_id; ___link_id = 0 /* always stop */) \ + list_for_each_entry(___sdata, &(_local)->interfaces, list) \ + if (___link_id == ARRAY_SIZE(___sdata->link) && \ + ieee80211_sdata_running(___sdata)) \ + for (___link_id = 0; \ ___link_id < ARRAY_SIZE((___sdata)->link); \ ___link_id++) \ if ((_link = rcu_dereference((___sdata)->link[___link_id]))) -- 2.47.3