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From:   =?UTF-8?q?Lu=C3=ADs=20Henriques?= <lhenriques@suse.de>
To:     Theodore Ts'o <tytso@mit.edu>,
        Andreas Dilger <adilger.kernel@dilger.ca>,
        Daniel Rosenberg <drosen@google.com>,
        Eric Biggers <ebiggers@kernel.org>
Cc:     linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
        =?UTF-8?q?Lu=C3=ADs=20Henriques?= <lhenriques@suse.de>
Subject: [PATCH v2] ext4: fix memory leaks in ext4_fname_{setup_filename,prepare_lookup}
Date:   Wed,  2 Aug 2023 10:49:31 +0100
Message-Id: <20230802094931.18215-1-lhenriques@suse.de>
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Precedence: bulk

If casefolding the filename fails, we'll be leaking fscrypt_buf name.
Make sure we free it in the error paths of ext4_fname_setup_filename() and
ext4_fname_prepare_lookup() functions.

Fixes: 1ae98e295fa2 ("ext4: optimize match for casefolded encrypted dirs")
Signed-off-by: Luís Henriques <lhenriques@suse.de>
---
Changes since v1:
- Include fix to ext4_fname_prepare_lookup() as well
- Add 'Fixes:' tag

 fs/ext4/crypto.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
index e20ac0654b3f..3c05c7f3415b 100644
--- a/fs/ext4/crypto.c
+++ b/fs/ext4/crypto.c
@@ -33,6 +33,8 @@ int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
 
 #if IS_ENABLED(CONFIG_UNICODE)
 	err = ext4_fname_setup_ci_filename(dir, iname, fname);
+	if (err)
+		fscrypt_free_filename(&name);
 #endif
 	return err;
 }
@@ -51,6 +53,8 @@ int ext4_fname_prepare_lookup(struct inode *dir, struct dentry *dentry,
 
 #if IS_ENABLED(CONFIG_UNICODE)
 	err = ext4_fname_setup_ci_filename(dir, &dentry->d_name, fname);
+	if (err)
+		fscrypt_free_filename(&name);
 #endif
 	return err;
 }