linux-ext4 - [PATCH 4/5] ext4: use EXT4_BAD_INO for buddy cache to avoid colliding with valid inode #

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]

Message-Id: <1312204398-12460-5-git-send-email-tytso@mit.edu>
Date:	Mon,  1 Aug 2011 09:13:17 -0400
From:	Theodore Ts'o <tytso@....edu>
To:	Ext4 Developers List <linux-ext4@...r.kernel.org>
Cc:	Yu Jian <yujian@...mcloud.com>,
	Andreas Dilger <adilger@...mcloud.com>,
	"Theodore Ts'o" <tytso@....edu>
Subject: [PATCH 4/5] ext4: use EXT4_BAD_INO for buddy cache to avoid colliding with valid inode #

From: Yu Jian <yujian@...mcloud.com>

Signed-off-by: Yu Jian <yujian@...mcloud.com>
Signed-off-by: Andreas Dilger <adilger@...mcloud.com>
Signed-off-by: "Theodore Ts'o" <tytso@....edu>
---
 fs/ext4/mballoc.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 262fa47..8beccd8 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2342,7 +2342,11 @@ static int ext4_mb_init_backend(struct super_block *sb)
 		ext4_msg(sb, KERN_ERR, "can't get new inode");
 		goto err_freesgi;
 	}
-	sbi->s_buddy_cache->i_ino = get_next_ino();
+	/* To avoid potentially colliding with an valid on-disk inode number,
+	 * use EXT4_BAD_INO for the buddy cache inode number.  This inode is
+	 * not in the inode hash, so it should never be found by iget(), but
+	 * this will avoid confusion if it ever shows up during debugging. */
+	sbi->s_buddy_cache->i_ino = EXT4_BAD_INO;
 	EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
 	for (i = 0; i < ngroups; i++) {
 		desc = ext4_get_group_desc(sb, i, NULL);
-- 
1.7.4.1.22.gec8e1.dirty

--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html