nfsd4: fix bare destroy_session null dereference
It's legal to send a DESTROY_SESSION outside any session (as the only
operation in a compound), in which case cstate->session will be NULL;
check for that case.
While we're at it, move these checks into a separate helper function.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index f05a327..835d6ce 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1352,6 +1352,13 @@
return argp->opcnt == resp->opcnt;
}
+static bool nfsd4_compound_in_session(struct nfsd4_session *session, struct nfs4_sessionid *sid)
+{
+ if (!session)
+ return 0;
+ return !memcmp(sid, &session->se_sessionid, sizeof(*sid));
+}
+
__be32
nfsd4_destroy_session(struct svc_rqst *r,
struct nfsd4_compound_state *cstate,
@@ -1367,8 +1374,7 @@
* - Do we need to clear any callback info from previous session?
*/
- if (!memcmp(&sessionid->sessionid, &cstate->session->se_sessionid,
- sizeof(struct nfs4_sessionid))) {
+ if (nfsd4_compound_in_session(cstate->session, &sessionid->sessionid)) {
if (!nfsd4_last_compound_op(r))
return nfserr_not_only_op;
}