You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
52 lines
2.0 KiB
52 lines
2.0 KiB
6 years ago
|
commit 49d0fe2a14f2a23da2fe299643379b8c1d37df73
|
||
|
|
Author: Theodore Ts'o <tytso@mit.edu>
|
||
|
|
Date: Fri Feb 6 12:46:39 2015 -0500
|
||
|
|
|
||
|
|
libext2fs: fix potential buffer overflow in closefs()
|
||
|
|
|
||
|
|
The bug fix in f66e6ce4446: "libext2fs: avoid buffer overflow if
|
||
|
|
s_first_meta_bg is too big" had a typo in the fix for
|
||
|
|
ext2fs_closefs(). In practice most of the security exposure was from
|
||
|
|
the openfs path, since this meant if there was a carefully crafted
|
||
|
|
file system, buffer overrun would be triggered when the file system was
|
||
|
|
opened.
|
||
|
|
|
||
|
|
However, if corrupted file system didn't trip over some corruption
|
||
|
|
check, and then the file system was modified via tune2fs or debugfs,
|
||
|
|
such that the superblock was marked dirty and then written out via the
|
||
|
|
closefs() path, it's possible that the buffer overrun could be
|
||
|
|
triggered when the file system is closed.
|
||
|
|
|
||
|
|
Also clear up a signed vs unsigned warning while we're at it.
|
||
|
|
|
||
|
|
Thanks to Nick Kralevich <nnk@google.com> for asking me to look at
|
||
|
|
compiler warning in the code in question, which led me to notice the
|
||
|
|
bug in f66e6ce4446.
|
||
|
|
|
||
|
|
Addresses: CVE-2015-1572
|
||
|
|
|
||
|
|
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
||
|
|
|
||
|
|
Index: e2fsprogs-1.42.9/lib/ext2fs/closefs.c
|
||
|
|
===================================================================
|
||
|
|
--- e2fsprogs-1.42.9.orig/lib/ext2fs/closefs.c
|
||
|
|
+++ e2fsprogs-1.42.9/lib/ext2fs/closefs.c
|
||
|
|
@@ -279,7 +279,7 @@ errcode_t ext2fs_flush2(ext2_filsys fs,
|
||
|
|
dgrp_t j;
|
||
|
|
#endif
|
||
|
|
char *group_ptr;
|
||
|
|
- int old_desc_blocks;
|
||
|
|
+ blk64_t old_desc_blocks;
|
||
|
|
struct ext2fs_numeric_progress_struct progress;
|
||
|
|
|
||
|
|
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
|
||
|
|
@@ -338,7 +338,7 @@ errcode_t ext2fs_flush2(ext2_filsys fs,
|
||
|
|
group_ptr = (char *) group_shadow;
|
||
|
|
if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) {
|
||
|
|
old_desc_blocks = fs->super->s_first_meta_bg;
|
||
|
|
- if (old_desc_blocks > fs->super->s_first_meta_bg)
|
||
|
|
+ if (old_desc_blocks > fs->desc_blocks)
|
||
|
|
old_desc_blocks = fs->desc_blocks;
|
||
|
|
} else
|
||
|
|
old_desc_blocks = fs->desc_blocks;
|