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authorRoland Dreier2008-09-26 00:26:15 +0200
committerRoland Dreier2008-09-26 00:26:15 +0200
commitc9da4bad5b80c3d9884e2c6ad8d2091252c32d5e (patch)
tree6b954f1ae170ffbbe522e38e3e69f44fc92f3689
parentMerge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6 (diff)
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IPoIB: Fix crash when path record fails after path flush
Commit ee1e2c82 ("IPoIB: Refresh paths instead of flushing them on SM change events") changed how paths are flushed on an SM event. This change introduces a problem if the path record query triggered by fails, causing path->ah to become NULL. A later successful path query will then trigger WARN_ON() in path_rec_completion(), and crash because path->ah has already been freed, so the ipoib_put_ah() inside the lock in path_rec_completion() may actually drop the last reference (contrary to the comment that claims this is safe). Fix this by updating path->ah and freeing old_ah only when the path record query is successful. This prevents the neighbour AH and that path AH from getting out of sync. This fixes <https://bugs.openfabrics.org/show_bug.cgi?id=1194> Reported-by: Rabah Salem <ravah@mellanox.com> Debugged-by: Eli Cohen <eli@mellanox.co.il> Signed-off-by: Roland Dreier <rolandd@cisco.com>
-rw-r--r--drivers/infiniband/ulp/ipoib/ipoib_main.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 1b1df5cc4113..e9ca3cb57d52 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -404,7 +404,7 @@ static void path_rec_completion(int status,
struct net_device *dev = path->dev;
struct ipoib_dev_priv *priv = netdev_priv(dev);
struct ipoib_ah *ah = NULL;
- struct ipoib_ah *old_ah;
+ struct ipoib_ah *old_ah = NULL;
struct ipoib_neigh *neigh, *tn;
struct sk_buff_head skqueue;
struct sk_buff *skb;
@@ -428,12 +428,12 @@ static void path_rec_completion(int status,
spin_lock_irqsave(&priv->lock, flags);
- old_ah = path->ah;
- path->ah = ah;
-
if (ah) {
path->pathrec = *pathrec;
+ old_ah = path->ah;
+ path->ah = ah;
+
ipoib_dbg(priv, "created address handle %p for LID 0x%04x, SL %d\n",
ah, be16_to_cpu(pathrec->dlid), pathrec->sl);