Manage: Manage_add(): Fix potential NULL pointer dereference

sysfs_read() may return NULL, so we should check the validity of the
pointer before dereferencing it.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>

diff --git a/Manage.c b/Manage.c
index 414373fe6ab2da88557fefffaa981baf01871262..a812ba05d33543488c45a697cdc72d3d06e09b0c 100644 (file)
--- a/Manage.c
+++ b/Manage.c
@@ -938,6 +938,10 @@ int Manage_add(int fd, int tfd, struct mddev_dev *dv,
                struct mdinfo *mdp;
 
                mdp = sysfs_read(fd, NULL, GET_ARRAY_STATE);
+               if (!mdp) {
+                       pr_err("%s unable to read array state.\n", devname);
+                       return -1;
+               }
 
                if (strncmp(mdp->sysfs_array_state, "readonly", 8) != 0) {
                        pr_err("%s is not readonly, cannot add journal.\n", devname);