Commit e53f1b04 authored by Zeng Heng's avatar Zeng Heng Committed by Baokun Li
Browse files

fs/ntfs3: fix panic about slab-out-of-bounds caused by ntfs_list_ea() 

mainline inclusion
from mainline-v6.6-rc7
commit 8e7e27b2
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9E2O5
CVE: CVE-2023-52640

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8e7e27b2ee1e19c4040d4987e345f678a74c0aed



--------------------------------

Here is a BUG report about linux-6.1 from syzbot, but it still remains
within upstream:

BUG: KASAN: slab-out-of-bounds in ntfs_list_ea fs/ntfs3/xattr.c:191 [inline]
BUG: KASAN: slab-out-of-bounds in ntfs_listxattr+0x401/0x570 fs/ntfs3/xattr.c:710
Read of size 1 at addr ffff888021acaf3d by task syz-executor128/3632

Call Trace:
 kasan_report+0x139/0x170 mm/kasan/report.c:495
 ntfs_list_ea fs/ntfs3/xattr.c:191 [inline]
 ntfs_listxattr+0x401/0x570 fs/ntfs3/xattr.c:710
 vfs_listxattr fs/xattr.c:457 [inline]
 listxattr+0x293/0x2d0 fs/xattr.c:804
 path_listxattr fs/xattr.c:828 [inline]
 __do_sys_llistxattr fs/xattr.c:846 [inline]

Before derefering field members of `ea` in unpacked_ea_size(), we need to
check whether the EA_FULL struct is located in access validate range.

Similarly, when derefering `ea->name` field member, we need to check
whethe the ea->name is located in access validate range, too.

Fixes: be71b5cb ("fs/ntfs3: Add attrib operations")
Reported-by: default avatar <syzbot+9fcea5ef6dc4dc72d334@syzkaller.appspotmail.com>
Signed-off-by: default avatarZeng Heng <zengheng4@huawei.com>
[almaz.alexandrovich@paragon-software.com: took the ret variable out of the loop block]
Signed-off-by: default avatarKonstantin Komarov <almaz.alexandrovich@paragon-software.com>
Signed-off-by: default avatarBaokun Li <libaokun1@huawei.com>
parent 318949c5

fs/ntfs3/xattr.c

+6 −1
Original line number Diff line number Diff line
@@ -209,7 +209,8 @@ static ssize_t ntfs_list_ea(struct ntfs_inode *ni, char *buffer, 
	size = le32_to_cpu(info->size);



	/* Enumerate all xattrs. */

	for (ret = 0, off = 0; off < size; off += ea_size) {

	ret = 0;

	for (off = 0; off + sizeof(struct EA_FULL) < size; off += ea_size) {

		ea = Add2Ptr(ea_all, off);

		ea_size = unpacked_ea_size(ea);
@@ -217,6 +218,10 @@ static ssize_t ntfs_list_ea(struct ntfs_inode *ni, char *buffer, 
			break;



		if (buffer) {

			/* Check if we can use field ea->name */

			if (off + ea_size > size)

				break;



			if (ret + ea->name_len + 1 > bytes_per_buffer) {

				err = -ERANGE;

				goto out;