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From:   Stanislav Goriainov <goriainov@ispras.ru>
To:     Miklos Szeredi <miklos@szeredi.hu>
Cc:     Stanislav Goriainov <goriainov@ispras.ru>,
        linux-unionfs@vger.kernel.org, linux-kernel@vger.kernel.org,
        ldv-project@linuxtesting.org
Subject: [PATCH] ovl: Fix potential memory leak
Date:   Mon, 22 Aug 2022 14:52:57 +0300
Message-Id: <20220822115257.7457-1-goriainov@ispras.ru>
MIME-Version: 1.0
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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@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