Fixes for issues found with cppcheck tool

The patch fixes small number of errors/false positives reported by `cppcheck`,
static analysis tool for C/C++.

cppcheck 1.72

$ cppcheck . --force --quiet
[cmd/zfs/zfs_main.c:4444]: (error) Possible null pointer dereference: who_perm
[cmd/zfs/zfs_main.c:4445]: (error) Possible null pointer dereference: who_perm
[cmd/zfs/zfs_main.c:4446]: (error) Possible null pointer dereference: who_perm
[cmd/zpool/zpool_iter.c:317]: (error) Uninitialized variable: nvroot
[cmd/zpool/zpool_vdev.c:1526]: (error) Memory leak: child
[lib/libefi/rdwr_efi.c:1118]: (error) Memory leak: efi_label
[lib/libuutil/uu_misc.c:207]: (error) va_list 'args' was opened but not closed by va_end().
[lib/libzfs/libzfs_import.c:1554]: (error) Dangerous usage of 'diskname' (strncpy doesn't always null-terminate it).
[lib/libzfs/libzfs_sendrecv.c:3279]: (error) Dereferencing 'cp' after it is deallocated / released
[tests/zfs-tests/cmd/file_write/file_write.c:154]: (error) Possible null pointer dereference: operation
[tests/zfs-tests/cmd/randfree_file/randfree_file.c:90]: (error) Memory leak: buf
[cmd/zinject/zinject.c:1068]: (error) Uninitialized variable: dataset
[module/icp/io/sha2_mod.c:698]: (error) Uninitialized variable: blocks_per_int64

Signed-off-by: Gvozden Neskovic <[email protected]>
Signed-off-by: Chunwei Chen <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #1392

4 files changed, 16 insertions, 5 deletions

diff --git a/cmd/zfs/zfs_main.c b/cmd/zfs/zfs_main.c
index e8a4421cc..8a8f56af9 100644
--- a/cmd/zfs/zfs_main.c
+++ b/cmd/zfs/zfs_main.c
@@ -4553,7 +4553,7 @@ parse_fs_perm(fs_perm_t *fsperm, nvlist_t *nvl)
 				who_perm = &node->who_perm;
 			}
 		}
-
+		VERIFY3P(who_perm, !=, NULL);
 		(void) parse_who_perm(who_perm, nvl2, perm_locality);
 	}
 
diff --git a/cmd/zinject/zinject.c b/cmd/zinject/zinject.c
index e687b733c..7e8381325 100644
--- a/cmd/zinject/zinject.c
+++ b/cmd/zinject/zinject.c
@@ -663,8 +663,8 @@ main(int argc, char **argv)
 	err_type_t type = TYPE_INVAL;
 	err_type_t label = TYPE_INVAL;
 	zinject_record_t record = { 0 };
-	char pool[MAXNAMELEN];
-	char dataset[MAXNAMELEN];
+	char pool[MAXNAMELEN] = "";
+	char dataset[MAXNAMELEN] = "";
 	zfs_handle_t *zhp = NULL;
 	int nowrites = 0;
 	int dur_txg = 0;
diff --git a/cmd/zpool/zpool_iter.c b/cmd/zpool/zpool_iter.c
index a18ccf29d..1b64a5a5c 100644
--- a/cmd/zpool/zpool_iter.c
+++ b/cmd/zpool/zpool_iter.c
@@ -308,7 +308,7 @@ for_each_vdev_cb(zpool_handle_t *zhp, nvlist_t *nv, pool_vdev_iter_f func,
 int
 for_each_vdev(zpool_handle_t *zhp, pool_vdev_iter_f func, void *data)
 {
-	nvlist_t *config, *nvroot;
+	nvlist_t *config, *nvroot = NULL;
 
 	if ((config = zpool_get_config(zhp, NULL)) != NULL) {
 		verify(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
diff --git a/cmd/zpool/zpool_vdev.c b/cmd/zpool/zpool_vdev.c
index 587aa7fd4..3f419079c 100644
--- a/cmd/zpool/zpool_vdev.c
+++ b/cmd/zpool/zpool_vdev.c
@@ -1522,8 +1522,13 @@ construct_spec(nvlist_t *props, int argc, char **argv)
 				if (child == NULL)
 					zpool_no_memory();
 				if ((nv = make_leaf_vdev(props, argv[c],
-				    B_FALSE)) == NULL)
+				    B_FALSE)) == NULL) {
+					for (c = 0; c < children - 1; c++)
+						nvlist_free(child[c]);
+					free(child);
 					return (NULL);
+				}
+
 				child[children - 1] = nv;
 			}
 
@@ -1531,6 +1536,9 @@ construct_spec(nvlist_t *props, int argc, char **argv)
 				(void) fprintf(stderr, gettext("invalid vdev "
 				    "specification: %s requires at least %d "
 				    "devices\n"), argv[0], mindev);
+				for (c = 0; c < children; c++)
+					nvlist_free(child[c]);
+				free(child);
 				return (NULL);
 			}
 
@@ -1538,6 +1546,9 @@ construct_spec(nvlist_t *props, int argc, char **argv)
 				(void) fprintf(stderr, gettext("invalid vdev "
 				    "specification: %s supports no more than "
 				    "%d devices\n"), argv[0], maxdev);
+				for (c = 0; c < children; c++)
+					nvlist_free(child[c]);
+				free(child);
 				return (NULL);
 			}