From: Aditya Kumar Singh <quic_adisi@xxxxxxxxxxx>
[ Upstream commit b5c32ff6a3a38c74facdd1fe34c0d709a55527fd ]
Currently, during link deletion, the link ID is first removed from the
valid_links bitmap before performing any clean-up operations. However, some
functions require the link ID to remain in the valid_links bitmap. One
such example is cfg80211_cac_event(). The flow is -
nl80211_remove_link()
cfg80211_remove_link()
ieee80211_del_intf_link()
ieee80211_vif_set_links()
ieee80211_vif_update_links()
ieee80211_link_stop()
cfg80211_cac_event()
cfg80211_cac_event() requires link ID to be present but it is cleared
already in cfg80211_remove_link(). Ultimately, WARN_ON() is hit.
Therefore, clear the link ID from the bitmap only after completing the link
clean-up.
Signed-off-by: Aditya Kumar Singh <quic_adisi@xxxxxxxxxxx>
Link: https://patch.msgid.link/20241121-mlo_dfs_fix-v2-1-92c3bf7ab551@xxxxxxxxxxx
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/mac80211/cfg.c | 8 +++++++-
net/wireless/util.c | 3 +--
2 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 6dfc61a9acd4..d589ea12e596 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -4993,10 +4993,16 @@ static void ieee80211_del_intf_link(struct wiphy *wiphy,
unsigned int link_id)
{
struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
+ u16 new_links = wdev->valid_links & ~BIT(link_id);
lockdep_assert_wiphy(sdata->local->hw.wiphy);
- ieee80211_vif_set_links(sdata, wdev->valid_links, 0);
+ /* During the link teardown process, certain functions require the
+ * link_id to remain in the valid_links bitmap. Therefore, instead
+ * of removing the link_id from the bitmap, pass a masked value to
+ * simulate as if link_id does not exist anymore.
+ */
+ ieee80211_vif_set_links(sdata, new_links, 0);
}
static int
diff --git a/net/wireless/util.c b/net/wireless/util.c
index f49b55724f83..18585b1416c6 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -2843,10 +2843,9 @@ void cfg80211_remove_link(struct wireless_dev *wdev, unsigned int link_id)
break;
}
- wdev->valid_links &= ~BIT(link_id);
-
rdev_del_intf_link(rdev, wdev, link_id);
+ wdev->valid_links &= ~BIT(link_id);
eth_zero_addr(wdev->links[link_id].addr);
}
--
2.39.5
