* [PATCH v2] mac80211: mesh: do mesh rhashtable walks with BHs disabled
@ 2019-02-05 20:22 Johannes Berg
0 siblings, 0 replies; only message in thread
From: Johannes Berg @ 2019-02-05 20:22 UTC (permalink / raw)
To: linux-wireless; +Cc: Johannes Berg
From: Johannes Berg <johannes.berg@intel.com>
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@w1.fi>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
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
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