[ldv-project] [PATCH] ovl: Fix potential memory leak

[Stanislav Goriainov]

ovl: Fix potential memory leak in ovl_lookup()

If memory for uperredirect was allocated with kstrdup()
in upperdir != NULL and d.redirect != NULL path,
it may be lost when upperredirect is reassigned later.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Stanislav Goriainov <goriainov at ispras.ru>
---
 fs/overlayfs/namei.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 69dc577974f8..226c69812379 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -1085,6 +1085,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
 			.mnt = ovl_upper_mnt(ofs),
 		};
 
+		kfree(upperredirect);
 		upperredirect = ovl_get_redirect_xattr(ofs, &upperpath, 0);
 		if (IS_ERR(upperredirect)) {
 			err = PTR_ERR(upperredirect);
-- 
2.34.1