[PATCH v3 ipsec-next 1/3] xfrm: check for xdo_dev_state_free

[Shannon Nelson]

The current XFRM code assumes that we've implemented the
xdo_dev_state_free() callback, even if it is meaningless to the driver.
This patch adds a check for it before calling, as done in other APIs,
to prevent a NULL function pointer kernel crash.

Signed-off-by: Shannon Nelson <shannon.nel...@oracle.com>
---
 include/net/xfrm.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index e015e16..dfabd04 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1891,7 +1891,8 @@ static inline void xfrm_dev_state_free(struct xfrm_state 
*x)
         struct net_device *dev = xso->dev;
 
        if (dev && dev->xfrmdev_ops) {
-               dev->xfrmdev_ops->xdo_dev_state_free(x);
+               if (dev->xfrmdev_ops->xdo_dev_state_free)
+                       dev->xfrmdev_ops->xdo_dev_state_free(x);
                xso->dev = NULL;
                dev_put(dev);
        }
-- 
2.7.4