linux/fs/f2fs
Chao Yu dd6c89b5f2 f2fs: fix to do sanity check with inode.i_inline_xattr_size
As Paul Bandha reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=202709

When I run the poc on the mounted f2fs img I get a buffer overflow in
read_inline_xattr due to there being no sanity check on the value of
i_inline_xattr_size.

I created the img by just modifying the value of i_inline_xattr_size
in the inode:

i_name                        		[test1.txt]
i_ext: fofs:0 blkaddr:0 len:0
i_extra_isize                 		[0x      18 : 24]
i_inline_xattr_size           		[0x    ffff : 65535]
i_addr[ofs]                   		[0x       0 : 0]

mkdir /mnt/f2fs
mount ./f2fs1.img /mnt/f2fs
gcc poc.c -o poc
./poc

int main() {
	int y = syscall(SYS_listxattr, "/mnt/f2fs/test1.txt", NULL, 0);
	printf("ret %d", y);
	printf("errno: %d\n", errno);

}

 BUG: KASAN: slab-out-of-bounds in read_inline_xattr+0x18f/0x260
 Read of size 262140 at addr ffff88011035efd8 by task f2fs1poc/3263

 CPU: 0 PID: 3263 Comm: f2fs1poc Not tainted 4.18.0-custom #1
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.1-0-g0551a4be2c-prebuilt.qemu-project.org 04/01/2014
 Call Trace:
  dump_stack+0x71/0xab
  print_address_description+0x83/0x250
  kasan_report+0x213/0x350
  memcpy+0x1f/0x50
  read_inline_xattr+0x18f/0x260
  read_all_xattrs+0xba/0x190
  f2fs_listxattr+0x9d/0x3f0
  listxattr+0xb2/0xd0
  path_listxattr+0x93/0xe0
  do_syscall_64+0x9d/0x220
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Let's add sanity check for inode.i_inline_xattr_size during f2fs_iget()
to avoid this issue.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2019-03-12 19:02:26 -07:00
..
acl.c f2fs: use kvmalloc, if kmalloc is failed 2018-12-26 15:16:53 -08:00
acl.h f2fs: add SPDX license identifiers 2018-09-12 13:07:10 -07:00
checkpoint.c f2fs: fix to add refcount once page is tagged PG_private 2019-03-12 18:59:19 -07:00
data.c f2fs: don't trigger read IO for beyond EOF page 2019-03-12 18:59:19 -07:00
debug.c f2fs: no need to check return value of debugfs_create functions 2019-01-08 20:41:09 -08:00
dir.c f2fs: fix to add refcount once page is tagged PG_private 2019-03-12 18:59:19 -07:00
extent_cache.c f2fs: fix to initialize variable to avoid UBSAN/smatch warning 2019-01-22 15:31:26 -08:00
f2fs.h f2fs: fix to add refcount once page is tagged PG_private 2019-03-12 18:59:19 -07:00
file.c f2fs: trace f2fs_ioc_shutdown 2019-03-12 18:59:19 -07:00
gc.c f2fs: check PageWriteback flag for ordered case 2018-12-26 15:16:56 -08:00
gc.h f2fs: add SPDX license identifiers 2018-09-12 13:07:10 -07:00
hash.c f2fs: add SPDX license identifiers 2018-09-12 13:07:10 -07:00
inline.c f2fs: fix potential data inconsistence of checkpoint 2019-03-05 19:58:06 -08:00
inode.c f2fs: fix to do sanity check with inode.i_inline_xattr_size 2019-03-12 19:02:26 -07:00
Kconfig fs/*/Kconfig: drop links to 404-compliant http://acl.bestbits.at 2018-01-01 12:45:37 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
namei.c f2fs: give random value to i_generation 2019-03-12 18:59:18 -07:00
node.c f2fs: fix to add refcount once page is tagged PG_private 2019-03-12 18:59:19 -07:00
node.h f2fs: check PageWriteback flag for ordered case 2018-12-26 15:16:56 -08:00
recovery.c f2fs: check PageWriteback flag for ordered case 2018-12-26 15:16:56 -08:00
segment.c f2fs: fix to add refcount once page is tagged PG_private 2019-03-12 18:59:19 -07:00
segment.h f2fs: don't wake up too frequently, if there is lots of IOs 2019-02-15 20:59:45 -08:00
shrinker.c f2fs: fix sbi->extent_list corruption issue 2018-12-26 15:16:54 -08:00
super.c f2fs: fix to do sanity check with inode.i_inline_xattr_size 2019-03-12 19:02:26 -07:00
sysfs.c f2fs: run discard jobs when put_super 2019-02-04 08:55:34 -08:00
trace.c f2fs: do not use mutex lock in atomic context 2019-03-05 19:58:06 -08:00
trace.h f2fs: add SPDX license identifiers 2018-09-12 13:07:10 -07:00
xattr.c f2fs: fix to use kvfree instead of kzfree 2019-03-12 18:59:19 -07:00
xattr.h f2fs: fix to do sanity check with inode.i_inline_xattr_size 2019-03-12 19:02:26 -07:00