linux-ext4 - [PATCH 2/5] ext4: Simplify the handling of chached insensitive names

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 21 Mar 2022 23:00:01 -0400
From:   Gabriel Krisman Bertazi <krisman@...labora.com>
To:     tytso@....edu
Cc:     ebiggers@...nel.org, jaegeuk@...nel.org,
        linux-ext4@...r.kernel.org,
        Gabriel Krisman Bertazi <krisman@...labora.com>,
        kernel@...labora.com
Subject: [PATCH 2/5] ext4: Simplify the handling of chached insensitive names

Keeping it as qstr avoids the unnecessary conversion in ext4_match

Signed-off-by: Gabriel Krisman Bertazi <krisman@...labora.com>
---
 fs/ext4/ext4.h  |  2 +-
 fs/ext4/namei.c | 23 +++++++++++------------
 2 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index bcd3b9bf8069..46e729ce7b35 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2484,7 +2484,7 @@ struct ext4_filename {
 	struct fscrypt_str crypto_buf;
 #endif
 #if IS_ENABLED(CONFIG_UNICODE)
-	struct fscrypt_str cf_name;
+	struct qstr cf_name;
 #endif
 };
 
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 24ea3bb446d0..8976e5a28c73 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1382,28 +1382,29 @@ static int ext4_ci_compare(const struct inode *parent, const struct qstr *name,
 int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
 				  struct ext4_filename *name)
 {
-	struct fscrypt_str *cf_name = &name->cf_name;
+	struct qstr *cf_name = &name->cf_name;
+	unsigned char *buf;
 	struct dx_hash_info *hinfo = &name->hinfo;
 	int len;
 
 	if (!IS_CASEFOLDED(dir) || !dir->i_sb->s_encoding ||
 	    (IS_ENCRYPTED(dir) && !fscrypt_has_encryption_key(dir))) {
-		cf_name->name = NULL;
+		name->cf_name.name = NULL;
 		return 0;
 	}
 
-	cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
-	if (!cf_name->name)
+	buf = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
+	if (!buf)
 		return -ENOMEM;
 
-	len = utf8_casefold(dir->i_sb->s_encoding,
-			    iname, cf_name->name,
-			    EXT4_NAME_LEN);
+	len = utf8_casefold(dir->i_sb->s_encoding, iname, buf, EXT4_NAME_LEN);
 	if (len <= 0) {
-		kfree(cf_name->name);
-		cf_name->name = NULL;
+		kfree(buf);
+		buf = NULL;
 	}
+	cf_name->name = buf;
 	cf_name->len = (unsigned) len;
+
 	if (!IS_ENCRYPTED(dir))
 		return 0;
 
@@ -1442,8 +1443,6 @@ static bool ext4_match(struct inode *parent,
 	if (parent->i_sb->s_encoding && IS_CASEFOLDED(parent) &&
 	    (!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) {
 		if (fname->cf_name.name) {
-			struct qstr cf = {.name = fname->cf_name.name,
-					  .len = fname->cf_name.len};
 			if (IS_ENCRYPTED(parent)) {
 				if (fname->hinfo.hash != EXT4_DIRENT_HASH(de) ||
 					fname->hinfo.minor_hash !=
@@ -1452,7 +1451,7 @@ static bool ext4_match(struct inode *parent,
 					return false;
 				}
 			}
-			ret = ext4_ci_compare(parent, &cf, de->name,
+			ret = ext4_ci_compare(parent, &fname->cf_name, de->name,
 					      de->name_len, true);
 		} else {
 			ret = ext4_ci_compare(parent, fname->usr_fname,
-- 
2.35.1