f2fs: avoid null dereference in f2fs_acl_from_disk

This patch resolves Coverity #751303:

>>> CID 753103: Explicit null dereferenced (FORWARD_NULL) Passing null
>>> pointer "value" to function "f2fs_acl_from_disk(char const *, size_t)",
	which dereferences it.

[Error path]
- value = NULL;
- retval = 0 by f2fs_getxattr();
- f2fs_acl_from_disk(value:NULL, ...);

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

diff --git a/fs/f2fs/acl.c b/fs/f2fs/acl.c
index e95b94945d5f4e8d93413c77c23d1db4d414b85b..137af4255da6dfab591e4d640821539663d01a7c 100644 (file)
--- a/fs/f2fs/acl.c
+++ b/fs/f2fs/acl.c
@@ -191,15 +191,14 @@ struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
                retval = f2fs_getxattr(inode, name_index, "", value, retval);
        }
 
-       if (retval < 0) {
-               if (retval == -ENODATA)
-                       acl = NULL;
-               else
-                       acl = ERR_PTR(retval);
-       } else {
+       if (retval > 0)
                acl = f2fs_acl_from_disk(value, retval);
-       }
+       else if (retval == -ENODATA)
+               acl = NULL;
+       else
+               acl = ERR_PTR(retval);
        kfree(value);
+
        if (!IS_ERR(acl))
                set_cached_acl(inode, type, acl);