linux-ext4 - [PATCH 1/2] e2fsprogs: fix data lost with mke2fs -S

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-next>] [day] [month] [year] [list]

Message-ID: <4EF2EA9E.9080500@rs.jp.nec.com>
Date:	Thu, 22 Dec 2011 17:30:22 +0900
From:	Akira Fujita <a-fujita@...jp.nec.com>
To:	Theodore Tso <tytso@....edu>,
	ext4 development <linux-ext4@...r.kernel.org>
Subject: [PATCH 1/2] e2fsprogs: fix data lost with mke2fs -S

If we run the mke2fs with the -S option and the uninit_bg feature
simultaneously, the mke2fs marks blockgroups as uninitialized.
The e2fsck which run immediately after the mke2fs
removes all of the files.

To avoid this, the patch prohibits user from
setting the -S option and the uninit_bg feature simultaneously.

Usage example of the mke2fsk -S is as follows:

1. mke2fs -t ext4 -S -O ^uninit_bg DEV
2. tune2fs -O uninit_bg DEV 
3. e2fsck DEV

#2 is not necessary only if the uninit_bg feature is not set
to ext4 originally. 

Signed-off-by: Akira Fujita <a-fujita@...jp.nec.com>
---
 misc/mke2fs.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/misc/mke2fs.c b/misc/mke2fs.c
index 0ef2531..19f3684 100644
--- a/misc/mke2fs.c
+++ b/misc/mke2fs.c
@@ -1676,6 +1676,16 @@ profile_error:
        if (tmp)
                free(tmp);

+       if (super_only == 1 &&
+           EXT2_HAS_RO_COMPAT_FEATURE((&fs_param),
+                                       EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
+               fprintf(stderr, _("The -S option and the uninit_bg feature "
+                                 "are not compatible.\n"
+                                 "They can not be set both "
+                                 "simultaneously.\n"));
+               exit(1);
+       }
+
        /*
         * We now need to do a sanity check of fs_blocks_count for
         * 32-bit vs 64-bit block number support.
--
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