Commit 5869357f authored by Ferry Meng's avatar Ferry Meng Committed by Yu Liao
Browse files

ocfs2: strict bound check before memcmp in ocfs2_xattr_find_entry() 

mainline inclusion
from mainline-v6.11-rc1
commit af77c4fc1871847b528d58b7fdafb4aa1f6a9262
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAG8SI
CVE: CVE-2024-41016

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=af77c4fc1871847b528d58b7fdafb4aa1f6a9262

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

xattr in ocfs2 maybe 'non-indexed', which saved with additional space
requested.  It's better to check if the memory is out of bound before
memcmp, although this possibility mainly comes from crafted poisonous
images.

Link: https://lkml.kernel.org/r/20240520024024.1976129-2-joseph.qi@linux.alibaba.com


Signed-off-by: default avatarFerry Meng <mengferry@linux.alibaba.com>
Signed-off-by: default avatarJoseph Qi <joseph.qi@linux.alibaba.com>
Reported-by: default avatarlei lu <llfamsec@gmail.com>
Reviewed-by: default avatarJoseph Qi <joseph.qi@linux.alibaba.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarYu Liao <liaoyu15@huawei.com>
parent 358d5c21

fs/ocfs2/xattr.c

+10 −5
Original line number Diff line number Diff line
@@ -1068,7 +1068,7 @@ static int ocfs2_xattr_find_entry(struct inode *inode, int name_index, 
{

	struct ocfs2_xattr_entry *entry;

	size_t name_len;

	int i, cmp = 1;

	int i, name_offset, cmp = 1;



	if (name == NULL)

		return -EINVAL;
@@ -1083,10 +1083,15 @@ static int ocfs2_xattr_find_entry(struct inode *inode, int name_index, 
		cmp = name_index - ocfs2_xattr_get_type(entry);

		if (!cmp)

			cmp = name_len - entry->xe_name_len;

		if (!cmp)

			cmp = memcmp(name, (xs->base +

				     le16_to_cpu(entry->xe_name_offset)),

				     name_len);

		if (!cmp) {

			name_offset = le16_to_cpu(entry->xe_name_offset);

			if ((xs->base + name_offset + name_len) > xs->end) {

				ocfs2_error(inode->i_sb,

					    "corrupted xattr entries");

				return -EFSCORRUPTED;

			}

			cmp = memcmp(name, (xs->base + name_offset), name_len);

		}

		if (cmp == 0)

			break;

		entry += 1;