Re: [PATCH] ext4: fix memory leak in ext4_fname_setup_filename() error path

Eric Biggers [off-list ref] writes:

On Tue, Aug 01, 2023 at 03:41:36PM +0100, Luís Henriques wrote:

quoted

If casefolding the filename fails, we'll be leaking fscrypt_buf name.
Make sure we free it in the error path.

Signed-off-by: Luís Henriques <redacted>
---
 fs/ext4/crypto.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
index e20ac0654b3f..9e4503b051c4 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;
 }

Doesn't ext4_fname_prepare_lookup() have the same bug?

Doh! I looked into that function too and then completely forgot about it.
It may also call fscrypt_setup_filename(), so it has to do the free in the
error path as well.  I'll send out v2 to include that fix too.

Also, please include a Fixes tag.

Ok, makes sense.  Thanks!

Cheers,
-- 
Luís