net/9p: Add a Warning to catch NULL fids passed to p9_client_clunk().

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/net/9p/client.c b/net/9p/client.c
index c155cc45eff9..e50ec802937a 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1168,6 +1168,12 @@ int p9_client_clunk(struct p9_fid *fid)
         struct p9_client *clnt;
         struct p9_req_t *req;
 
+        if (!fid) {
+                P9_EPRINTK(KERN_WARNING, "Trying to clunk with NULL fid\n");
+                dump_stack();
+                return 0;
+        }
+
         P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
         err = 0;
         clnt = fid->clnt;