From: Johannes Berg <johannes.berg@xxxxxxxxx> Since we do some walks from *within* softirq context and the rhashtable code just uses a plain spin_lock(), we need to disable softirqs for other walks that are not within softirq context to avoid a potential deadlock (taking a softirq that takes the spinlock while inside the spinlock from regular process context.) Reported-by: Jouni Malinen <j@xxxxx> Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> --- net/mac80211/mesh_pathtbl.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c index a5125624a76d..f235a05b8226 100644 --- a/net/mac80211/mesh_pathtbl.c +++ b/net/mac80211/mesh_pathtbl.c @@ -574,9 +574,11 @@ void mesh_path_flush_by_nexthop(struct sta_info *sta) struct rhashtable_iter iter; int ret; + local_bh_disable(); + ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC); if (ret) - return; + goto out; rhashtable_walk_start(&iter); @@ -592,6 +594,8 @@ void mesh_path_flush_by_nexthop(struct sta_info *sta) rhashtable_walk_stop(&iter); rhashtable_walk_exit(&iter); +out: + local_bh_enable(); } static void mpp_flush_by_proxy(struct ieee80211_sub_if_data *sdata, @@ -602,9 +606,10 @@ static void mpp_flush_by_proxy(struct ieee80211_sub_if_data *sdata, struct rhashtable_iter iter; int ret; + local_bh_disable(); ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC); if (ret) - return; + goto out; rhashtable_walk_start(&iter); @@ -620,6 +625,8 @@ static void mpp_flush_by_proxy(struct ieee80211_sub_if_data *sdata, rhashtable_walk_stop(&iter); rhashtable_walk_exit(&iter); +out: + local_bh_enable(); } static void table_flush_by_iface(struct mesh_table *tbl) @@ -628,9 +635,10 @@ static void table_flush_by_iface(struct mesh_table *tbl) struct rhashtable_iter iter; int ret; + local_bh_disable(); ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC); if (ret) - return; + goto out; rhashtable_walk_start(&iter); @@ -644,6 +652,8 @@ static void table_flush_by_iface(struct mesh_table *tbl) rhashtable_walk_stop(&iter); rhashtable_walk_exit(&iter); +out: + local_bh_enable(); } /** @@ -857,9 +867,10 @@ void mesh_path_tbl_expire(struct ieee80211_sub_if_data *sdata, struct rhashtable_iter iter; int ret; + local_bh_disable(); ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_KERNEL); if (ret) - return; + goto out; rhashtable_walk_start(&iter); @@ -876,6 +887,8 @@ void mesh_path_tbl_expire(struct ieee80211_sub_if_data *sdata, rhashtable_walk_stop(&iter); rhashtable_walk_exit(&iter); +out: + local_bh_enable(); } void mesh_path_expire(struct ieee80211_sub_if_data *sdata) -- 2.17.2
