fs/squashfs: sqfs_get_abs_path: fix possible memory leak on error

if  sqfs_tokenize(rel_tokens, rc, rel); fails, the function exits
without freeing the array base_tokens.

Reviewed-by: Joao Marcos Costa <jmcosta944@gmail.com>
Signed-off-by: Richard Genoud <richard.genoud@posteo.net>

diff --git a/fs/squashfs/sqfs.c b/fs/squashfs/sqfs.c
index 825d5d1..f41deec 100644 (file)
--- a/fs/squashfs/sqfs.c
+++ b/fs/squashfs/sqfs.c
@@ -340,28 +340,31 @@ static char *sqfs_get_abs_path(const char *base, const char *rel)
        char **base_tokens, **rel_tokens, *resolved = NULL;
        int ret, bc, rc, i, updir = 0, resolved_size = 0, offset = 0;
 
+       base_tokens = NULL;
+       rel_tokens = NULL;
+
        /* Memory allocation for the token lists */
        bc = sqfs_count_tokens(base);
        rc = sqfs_count_tokens(rel);
        if (bc < 1 || rc < 1)
                return NULL;
 
-       base_tokens = malloc(bc * sizeof(char *));
+       base_tokens = calloc(bc, sizeof(char *));
        if (!base_tokens)
                return NULL;
 
-       rel_tokens = malloc(rc * sizeof(char *));
+       rel_tokens = calloc(rc, sizeof(char *));
        if (!rel_tokens)
-               goto free_b_tokens;
+               goto out;
 
        /* Fill token lists */
        ret = sqfs_tokenize(base_tokens, bc, base);
        if (ret)
-               goto free_r_tokens;
+               goto out;
 
        ret = sqfs_tokenize(rel_tokens, rc, rel);
        if (ret)
-               goto free_r_tokens;
+               goto out;
 
        /* count '..' occurrences in target path */
        for (i = 0; i < rc; i++) {
@@ -372,7 +375,7 @@ static char *sqfs_get_abs_path(const char *base, const char *rel)
        /* Remove the last token and the '..' occurrences */
        bc = sqfs_clean_base_path(base_tokens, bc, updir);
        if (bc < 0)
-               goto free_r_tokens;
+               goto out;
 
        /* Calculate resolved path size */
        if (!bc)
@@ -383,7 +386,7 @@ static char *sqfs_get_abs_path(const char *base, const char *rel)
 
        resolved = malloc(resolved_size + 1);
        if (!resolved)
-               goto free_r_tokens_loop;
+               goto out;
 
        /* Set resolved path */
        memset(resolved, '\0', resolved_size + 1);
@@ -391,14 +394,15 @@ static char *sqfs_get_abs_path(const char *base, const char *rel)
        resolved[offset++] = '/';
        offset += sqfs_join(rel_tokens, resolved + offset, updir, rc, '/');
 
-free_r_tokens_loop:
-       for (i = 0; i < rc; i++)
-               free(rel_tokens[i]);
-       for (i = 0; i < bc; i++)
-               free(base_tokens[i]);
-free_r_tokens:
+out:
+       if (rel_tokens)
+               for (i = 0; i < rc; i++)
+                       free(rel_tokens[i]);
+       if (base_tokens)
+               for (i = 0; i < bc; i++)
+                       free(base_tokens[i]);
+
        free(rel_tokens);
-free_b_tokens:
        free(base_tokens);
 
        return resolved;