libnvdimm, namespace: potential NULL deref on allocation error

If the kcalloc() fails then "devs" can be NULL and we dereference it
checking "devs[i]".

Fixes: 1b40e09a1232 ('libnvdimm: blk labels and namespace instantiation')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index 3509cff68ef9..abe5c6bc756c 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -2176,12 +2176,14 @@ static struct device **scan_labels(struct nd_region *nd_region)
         return devs;
 
  err:
-        for (i = 0; devs[i]; i++)
-                if (is_nd_blk(&nd_region->dev))
-                        namespace_blk_release(devs[i]);
-                else
-                        namespace_pmem_release(devs[i]);
-        kfree(devs);
+        if (devs) {
+                for (i = 0; devs[i]; i++)
+                        if (is_nd_blk(&nd_region->dev))
+                                namespace_blk_release(devs[i]);
+                        else
+                                namespace_pmem_release(devs[i]);
+                kfree(devs);
+        }
         return NULL;
 }