mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-05 10:31:46 +09:00
e60b972319
commit 0cfe75c5b0 upstream.
In order to avoid the below overflow issue, we should have checked the
boundaries in superblock before reaching out to allocation. As Linus suggested,
the right place should be sanity_check_raw_super().
Dr Silvio Cesare of InfoSect reported:
There are integer overflows with using the cp_payload superblock field in the
f2fs filesystem potentially leading to memory corruption.
include/linux/f2fs_fs.h
struct f2fs_super_block {
...
__le32 cp_payload;
fs/f2fs/f2fs.h
typedef u32 block_t; /*
* should not change u32, since it is the on-disk block
* address format, __le32.
*/
...
static inline block_t __cp_payload(struct f2fs_sb_info *sbi)
{
return le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_payload);
}
fs/f2fs/checkpoint.c
block_t start_blk, orphan_blocks, i, j;
...
start_blk = __start_cp_addr(sbi) + 1 + __cp_payload(sbi);
orphan_blocks = __start_sum_addr(sbi) - 1 - __cp_payload(sbi);
+++ integer overflows
...
unsigned int cp_blks = 1 + __cp_payload(sbi);
...
sbi->ckpt = kzalloc(cp_blks * blk_size, GFP_KERNEL);
+++ integer overflow leading to incorrect heap allocation.
int cp_payload_blks = __cp_payload(sbi);
...
ckpt->cp_pack_start_sum = cpu_to_le32(1 + cp_payload_blks +
orphan_blocks);
+++ sign bug and integer overflow
...
for (i = 1; i < 1 + cp_payload_blks; i++)
+++ integer overflow
...
sbi->max_orphans = (sbi->blocks_per_seg - F2FS_CP_PACKS -
NR_CURSEG_TYPE - __cp_payload(sbi)) *
F2FS_ORPHANS_PER_BLOCK;
+++ integer overflow
Reported-by: Greg KH <greg@kroah.com>
Reported-by: Silvio Cesare <silvio.cesare@gmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
[bwh: Backported to 4.14: No hot file extension support]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.