[PATCH v2] fs: ext4fs: Free memory while handling errors

[Francois Berder]

If zalloc fails, one needs to free memory previously
allocated in the function. This commit makes sure that
we do not leak any memory.

Signed-off-by: Francois Berder <fberder at outlook.fr>
---
 fs/ext4/ext4_common.c  | 6 +++++-
 fs/ext4/ext4_journal.c | 4 +++-
 fs/ext4/ext4_write.c   | 4 ++--
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c
index 8e6531fa3f0..9e1d574e5b1 100644
--- a/fs/ext4/ext4_common.c
+++ b/fs/ext4/ext4_common.c
@@ -727,8 +727,12 @@ static int parse_path(char **arr, char *dirname)
 	/* add each path entry after root */
 	while (token != NULL) {
 		arr[i] = zalloc(strlen(token) + 1);
-		if (!arr[i])
+		if (!arr[i]) {
+			while (i--)
+				free(arr[i]);
+
 			return -ENOMEM;
+		}
 		memcpy(arr[i++], token, strlen(token));
 		token = strtok(NULL, "/");
 	}
diff --git a/fs/ext4/ext4_journal.c b/fs/ext4/ext4_journal.c
index 868a2c1804a..3a2e9f30c12 100644
--- a/fs/ext4/ext4_journal.c
+++ b/fs/ext4/ext4_journal.c
@@ -256,8 +256,10 @@ void ext4fs_push_revoke_blk(char *buffer)
 	}
 
 	node->content = zalloc(fs->blksz);
-	if (node->content == NULL)
+	if (!node->content) {
+		free(node);
 		return;
+	}
 	memcpy(node->content, buffer, fs->blksz);
 
 	if (first_node == true) {
diff --git a/fs/ext4/ext4_write.c b/fs/ext4/ext4_write.c
index 5b290f0d80d..2b8ed1cd110 100644
--- a/fs/ext4/ext4_write.c
+++ b/fs/ext4/ext4_write.c
@@ -205,7 +205,7 @@ static void delete_double_indirect_block(struct ext2_inode *inode)
 		di_buffer = zalloc(fs->blksz);
 		if (!di_buffer) {
 			printf("No memory\n");
-			return;
+			goto fail;
 		}
 		dib_start_addr = di_buffer;
 		blknr = le32_to_cpu(inode->b.blocks.double_indir_block);
@@ -304,7 +304,7 @@ static void delete_triple_indirect_block(struct ext2_inode *inode)
 		tigp_buffer = zalloc(fs->blksz);
 		if (!tigp_buffer) {
 			printf("No memory\n");
-			return;
+			goto fail;
 		}
 		tib_start_addr = tigp_buffer;
 		blknr = le32_to_cpu(inode->b.blocks.triple_indir_block);
-- 
2.43.0