ext4: fix memory leaks in ext4_fname_{setup_filename,prepare_lookup}

commit 7ca4b085f430f3774c3838b3da569ceccd6a0177 upstream.

If the filename casefolding fails, we'll be leaking memory from the
fscrypt_name struct, namely from the 'crypto_buf.name' member.

Make sure we free it in the error path on both ext4_fname_setup_filename()
and ext4_fname_prepare_lookup() functions.

Cc: stable@kernel.org
Fixes: 1ae98e295fa2 ("ext4: optimize match for casefolded encrypted dirs")
Signed-off-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20230803091713.13239-1-lhenriques@suse.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
index e20ac0654b3f2dfa3213db10444dd8301cbb413f..453d4da5de5207ff3a2c19a74b5311f5ec54add8 100644 (file)
--- 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)
+               ext4_fname_free_filename(fname);
 #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)
+               ext4_fname_free_filename(fname);
 #endif
        return err;
 }