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authorPatrick McHardy <kaber@trash.net>2012-08-30 07:01:30 +0000
committerRoland Dreier <roland@purestorage.com>2012-09-30 20:32:33 -0700
commitbea1e22df494a729978e7f2c54f7bda328f74bc3 (patch)
tree89d9e7ce19232caf86b38833fdbacbe8517b1f97
parent979570e02981d4a8fc20b3cc8fd651856c98ee9d (diff)
downloadlinux-linaro-stable-bea1e22df494a729978e7f2c54f7bda328f74bc3.tar.gz
IPoIB: Fix use-after-free of multicast object
Fix a crash in ipoib_mcast_join_task(). (with help from Or Gerlitz) Commit c8c2afe360b7 ("IPoIB: Use rtnl lock/unlock when changing device flags") added a call to rtnl_lock() in ipoib_mcast_join_task(), which is run from the ipoib_workqueue, and hence the workqueue can't be flushed from the context of ipoib_stop(). In the current code, ipoib_stop() (which doesn't flush the workqueue) calls ipoib_mcast_dev_flush(), which goes and deletes all the multicast entries. This takes place without any synchronization with a possible running instance of ipoib_mcast_join_task() for the same ipoib device, leading to a crash due to NULL pointer dereference. Fix this by making sure that the workqueue is flushed before ipoib_mcast_dev_flush() is called. To make that possible, we move the RTNL-lock wrapped code to ipoib_mcast_join_finish(). Signed-off-by: Patrick McHardy <kaber@trash.net> Cc: <stable@vger.kernel.org> Signed-off-by: Roland Dreier <roland@purestorage.com>
-rw-r--r--drivers/infiniband/ulp/ipoib/ipoib_main.c2
-rw-r--r--drivers/infiniband/ulp/ipoib/ipoib_multicast.c19
2 files changed, 11 insertions, 10 deletions
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 1e19b5ae7c47..ea0dfc77a7f4 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -150,7 +150,7 @@ static int ipoib_stop(struct net_device *dev)
netif_stop_queue(dev);
- ipoib_ib_dev_down(dev, 0);
+ ipoib_ib_dev_down(dev, 1);
ipoib_ib_dev_stop(dev, 0);
if (!test_bit(IPOIB_FLAG_SUBINTERFACE, &priv->flags)) {
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index 75367249f447..cecb98a4c662 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -175,7 +175,9 @@ static int ipoib_mcast_join_finish(struct ipoib_mcast *mcast,
mcast->mcmember = *mcmember;
- /* Set the cached Q_Key before we attach if it's the broadcast group */
+ /* Set the multicast MTU and cached Q_Key before we attach if it's
+ * the broadcast group.
+ */
if (!memcmp(mcast->mcmember.mgid.raw, priv->dev->broadcast + 4,
sizeof (union ib_gid))) {
spin_lock_irq(&priv->lock);
@@ -183,10 +185,17 @@ static int ipoib_mcast_join_finish(struct ipoib_mcast *mcast,
spin_unlock_irq(&priv->lock);
return -EAGAIN;
}
+ priv->mcast_mtu = IPOIB_UD_MTU(ib_mtu_enum_to_int(priv->broadcast->mcmember.mtu));
priv->qkey = be32_to_cpu(priv->broadcast->mcmember.qkey);
spin_unlock_irq(&priv->lock);
priv->tx_wr.wr.ud.remote_qkey = priv->qkey;
set_qkey = 1;
+
+ if (!ipoib_cm_admin_enabled(dev)) {
+ rtnl_lock();
+ dev_set_mtu(dev, min(priv->mcast_mtu, priv->admin_mtu));
+ rtnl_unlock();
+ }
}
if (!test_bit(IPOIB_MCAST_FLAG_SENDONLY, &mcast->flags)) {
@@ -574,14 +583,6 @@ void ipoib_mcast_join_task(struct work_struct *work)
return;
}
- priv->mcast_mtu = IPOIB_UD_MTU(ib_mtu_enum_to_int(priv->broadcast->mcmember.mtu));
-
- if (!ipoib_cm_admin_enabled(dev)) {
- rtnl_lock();
- dev_set_mtu(dev, min(priv->mcast_mtu, priv->admin_mtu));
- rtnl_unlock();
- }
-
ipoib_dbg_mcast(priv, "successfully joined all multicast groups\n");
clear_bit(IPOIB_MCAST_RUN, &priv->flags);