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| author | Haogang Chen <haogangchen@gmail.com> | 2012-05-28 14:21:55 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2012-05-28 14:21:55 -0400 |
| commit | 967ac8af4475ce45474800709b12137aa7634c77 (patch) | |
| tree | b40d665c1620e801f313ff516c7986e8c3cdbd59 /fs/ext4/resize.c | |
| parent | 9d99012ff26380a09092a9fddbb6e5f996dc631f (diff) | |
| download | linux-967ac8af4475ce45474800709b12137aa7634c77.tar.gz linux-967ac8af4475ce45474800709b12137aa7634c77.tar.bz2 linux-967ac8af4475ce45474800709b12137aa7634c77.zip | |
ext4: fix potential integer overflow in alloc_flex_gd()
In alloc_flex_gd(), when flexbg_size is large, kmalloc size would
overflow and flex_gd->groups would point to a buffer smaller than
expected, causing OOB accesses when it is used.
Note that in ext4_resize_fs(), flexbg_size is calculated using
sbi->s_log_groups_per_flex, which is read from the disk and only bounded
to [1, 31]. The patch returns NULL for too large flexbg_size.
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Haogang Chen <haogangchen@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
Diffstat (limited to 'fs/ext4/resize.c')
| -rw-r--r-- | fs/ext4/resize.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index a58ce7c507ae..05c7979226e5 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -161,6 +161,8 @@ static struct ext4_new_flex_group_data *alloc_flex_gd(unsigned long flexbg_size) if (flex_gd == NULL) goto out3; + if (flexbg_size >= UINT_MAX / sizeof(struct ext4_new_flex_group_data)) + goto out2; flex_gd->count = flexbg_size; flex_gd->groups = kmalloc(sizeof(struct ext4_new_group_data) * |