vitalif
/
e2fsprogs
mirror of https://github.com/vitalif/e2fsprogs
1
0
Fork 0
Code Issues Releases Wiki Activity

libext2fs/e2fsck: don't run off the end of the EA block 

When we're (a) reading EAs into a buffer; (b) byte-swapping EA
entries; or (c) checking EA data, be careful not to run off the end of
the memory buffer, because this causes invalid memory accesses and
e2fsck crashes.  This can happen if we encounter a specially crafted
FS image.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
crypto
Darrick J. Wong 2014-08-10 18:22:07 -04:00 committed by Theodore Ts'o
parent 71e177a2a5
commit 88334ce084
3 changed files with 7 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
e2fsck/pass1.c
View File

@ -302,7 +302,8 @@ static void check_ea_in_inode(e2fsck_t ctx, struct problem_context *pctx)
/* take finish entry 0UL into account */
remain = storage_size - sizeof(__u32);
while (!EXT2_EXT_IS_LAST_ENTRY(entry)) {
while (remain >= sizeof(struct ext2_ext_attr_entry) &&
!EXT2_EXT_IS_LAST_ENTRY(entry)) {
__u32 hash;
/* header eats this space */

3
lib/ext2fs/ext_attr.c
View File

@ -633,7 +633,8 @@ static errcode_t read_xattrs_from_buffer(struct ext2_xattr_handle *handle,
entry = entries;
remain = storage_size;
while (!EXT2_EXT_IS_LAST_ENTRY(entry)) {
while (remain >= sizeof(struct ext2_ext_attr_entry) &&
!EXT2_EXT_IS_LAST_ENTRY(entry)) {
__u32 hash;
/* header eats this space */

4
lib/ext2fs/swapfs.c
View File

@ -196,7 +196,9 @@ void ext2fs_swap_ext_attr(char *to, char *from, int bufsize, int has_header)
to_entry = (struct ext2_ext_attr_entry *)to_header;
}
while ((char *)from_entry < from_end && *(__u32 *)from_entry) {
while ((char *)from_entry < from_end &&
(char *)EXT2_EXT_ATTR_NEXT(from_entry) <= from_end &&
*(__u32 *)from_entry) {
ext2fs_swap_ext_attr_entry(to_entry, from_entry);
from_entry = EXT2_EXT_ATTR_NEXT(from_entry);
to_entry = EXT2_EXT_ATTR_NEXT(to_entry);