From: Theodore Ts'o <tytso@mit.edu>
To: Ext4 Developers List <linux-ext4@vger.kernel.org>
Cc: gnehzuil.liu@gmail.com, Theodore Ts'o <tytso@mit.edu>
Subject: [PATCH 5/5] libext2fs: avoid 32-bit overflow in ext2fs_initialize with a 512M cluster size
Date: Mon, 14 Jan 2013 19:37:12 -0500 [thread overview]
Message-ID: <1358210232-30578-5-git-send-email-tytso@mit.edu> (raw)
In-Reply-To: <1358210232-30578-1-git-send-email-tytso@mit.edu>
If the user attemps to create a 512MB cluster, we need to adjust the
defaults to avoid a 32-bit overflow of s_blocks_per_group. Also check
to make sure that the caller of ext2fs_initialize() has not given a
value of s_clusters_per_group that would result in an overflow of
s_blocks_per_group.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---
lib/ext2fs/initialize.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/lib/ext2fs/initialize.c b/lib/ext2fs/initialize.c
index b0c15d2..5afdc27 100644
--- a/lib/ext2fs/initialize.c
+++ b/lib/ext2fs/initialize.c
@@ -207,6 +207,8 @@ errcode_t ext2fs_initialize(const char *name, int flags,
super->s_log_block_size;
if (bigalloc_flag) {
+ unsigned long long bpg;
+
if (param->s_blocks_per_group &&
param->s_clusters_per_group &&
((param->s_clusters_per_group * EXT2FS_CLUSTER_RATIO(fs)) !=
@@ -220,12 +222,19 @@ errcode_t ext2fs_initialize(const char *name, int flags,
super->s_clusters_per_group =
param->s_blocks_per_group /
EXT2FS_CLUSTER_RATIO(fs);
- else
+ else if (super->s_log_cluster_size + 15 < 32)
super->s_clusters_per_group = fs->blocksize * 8;
+ else
+ super->s_clusters_per_group = (fs->blocksize - 1) * 8;
if (super->s_clusters_per_group > EXT2_MAX_CLUSTERS_PER_GROUP(super))
super->s_clusters_per_group = EXT2_MAX_CLUSTERS_PER_GROUP(super);
- super->s_blocks_per_group = EXT2FS_C2B(fs,
- super->s_clusters_per_group);
+ bpg = EXT2FS_C2B(fs,
+ (unsigned long long) super->s_clusters_per_group);
+ if (bpg >= (((unsigned long long) 1) << 32)) {
+ retval = EXT2_ET_INVALID_ARGUMENT;
+ goto cleanup;
+ }
+ super->s_blocks_per_group = bpg;
} else {
set_field(s_blocks_per_group, fs->blocksize * 8);
if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super))
--
1.7.12.rc0.22.gcdd159b
next prev parent reply other threads:[~2013-01-15 0:37 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-13 9:08 [PATCH 1/3] mke2fs: indicate bigalloc feature explicity when cluster-size is enabled Zheng Liu
2013-01-13 9:08 ` [PATCH 2/3] mke2fs: reduce the range of cluster-size Zheng Liu
2013-01-14 17:41 ` Andreas Dilger
2013-01-14 21:03 ` Theodore Ts'o
2013-01-14 21:07 ` Andreas Dilger
2013-01-14 21:10 ` Theodore Ts'o
2013-01-15 0:37 ` [PATCH 1/5] mke2fs: enforce that the cluster size must be less that the block size Theodore Ts'o
2013-01-15 0:37 ` [PATCH 2/5] mke2fs: the -g option will now specify the clusters per block group Theodore Ts'o
2013-01-15 15:10 ` Eric Sandeen
2013-01-15 19:05 ` Theodore Ts'o
2013-01-15 15:22 ` Zheng Liu
2013-01-15 0:37 ` [PATCH 3/5] libe2p: teach parse_num_blocks2() to return bytes if log_block_size < 0 Theodore Ts'o
2013-01-15 15:23 ` Zheng Liu
2013-01-15 0:37 ` [PATCH 4/5] mke2fs: teach mke2fs to understand -b 4k and -C 256M Theodore Ts'o
2013-01-15 15:11 ` Eric Sandeen
2013-01-15 15:13 ` Eric Sandeen
2013-01-15 15:24 ` Zheng Liu
2013-01-15 0:37 ` Theodore Ts'o [this message]
2013-01-15 15:33 ` [PATCH 5/5] libext2fs: avoid 32-bit overflow in ext2fs_initialize with a 512M cluster size Zheng Liu
2013-01-15 15:36 ` Zheng Liu
2013-01-15 19:10 ` Theodore Ts'o
2013-01-16 1:49 ` Zheng Liu
2013-01-15 0:41 ` [PATCH 1/5] mke2fs: enforce that the cluster size must be less that the block size Theodore Ts'o
2013-01-15 15:22 ` Zheng Liu
2013-01-13 9:08 ` [PATCH 3/3] mke2fs: document bigalloc and cluster-size Zheng Liu
2013-01-15 3:10 ` Theodore Ts'o
2013-01-15 19:12 ` Theodore Ts'o
2013-01-15 19:46 ` Phillip Susi
2013-01-15 19:57 ` Theodore Ts'o
2013-01-15 20:38 ` Phillip Susi
2013-01-15 22:28 ` Theodore Ts'o
2013-01-14 20:28 ` [PATCH 1/3] mke2fs: indicate bigalloc feature explicity when cluster-size is enabled Theodore Ts'o
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