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: <1406359167-13610-1-git-send-email-a3at.mail@gmail.com>
Date:	Sat, 26 Jul 2014 11:19:27 +0400
From:	Azat Khuzhin <a3at.mail@...il.com>
To:	linux-ext4@...r.kernel.org
Cc:	lists2009@...rfbargle.com, tytso@....edu,
	Azat Khuzhin <a3at.mail@...il.com>
Subject: [PATCH] resize2fs: fix 32bit overflow during minimal size calculation for 64bit fs.

calculate_minimum_resize_size() multiplying two 32bit numbers, however the
result must be 64bit, but it will be truncated to 32bit, and because of this
data_blocks will be zero, and it will never leave loop:
blocks_per_group=32768 (u32)
extra_groups=131072 (u32)
data_blocks=4294967296 # overflow

And here is messages from log with resize2fs -f 255:
fs has 4007207 inodes, 1957 groups required.
fs requires 4374122900 data blocks.
With 1957 group(s), we have 63820826 blocks available.
Added 131540 extra group(s), blks_needed 4374122900, data_blocks·62023030, last_start 4356599580
Added 131595 extra group(s), blks_needed 4374122900, data_blocks·73483100, last_start 5781212288
Added 131246 extra group(s), blks_needed 4374122900, data_blocks·79184732, last_start 5781244926
Added 131072 extra group(s), blks_needed 4374122900, data_blocks·79184732, last_start 5781277564
Added 131072 extra group(s), blks_needed 4374122900, data_blocks·79184732, last_start 5781310202
...

Reported-by: Brad Campbell <lists2009@...rfbargle.com>
Tested-by: Brad Campbell <lists2009@...rfbargle.com>
Signed-off-by: Azat Khuzhin <a3at.mail@...il.com>
---
 resize/resize2fs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/resize/resize2fs.c b/resize/resize2fs.c
index 546b1d8..6777bfa 100644
--- a/resize/resize2fs.c
+++ b/resize/resize2fs.c
@@ -2479,7 +2479,8 @@ blk64_t calculate_minimum_resize_size(ext2_filsys fs, int flags)
 		extra_grps = ext2fs_div64_ceil(remainder,
 					       EXT2_BLOCKS_PER_GROUP(fs->super));
 
-		data_blocks += extra_grps * EXT2_BLOCKS_PER_GROUP(fs->super);
+		data_blocks += (unsigned long long)extra_grps *
+			EXT2_BLOCKS_PER_GROUP(fs->super);
 
 		/* ok we have to account for the last group */
 		overhead = calc_group_overhead(fs, groups-1, old_desc_blocks);
-- 
2.0.1

--
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

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ