• CVE-2024-35846

发布时间: 2024年6月15日

修改时间: 2025年1月4日

概要

In the Linux kernel, the following vulnerability has been resolved: mm: zswap: fix shrinker NULL crash with cgroup_disable=memory Christian reports a NULL deref in zswap that he bisected down to the zswap shrinker. The issue also cropped up in the bug trackers of libguestfs [1] and the Red Hat bugzilla [2]. The problem is that when memcg is disabled with the boot time flag, the zswap shrinker might get called with sc->memcg == NULL. This is okay in many places, like the lruvec operations. But it crashes in memcg_page_state() - which is only used due to the non-node accounting of cgroup's the zswap memory to begin with. Nhat spotted that the memcg can be NULL in the memcg-disabled case, and I was then able to reproduce the crash locally as well. [1] https://github.com/libguestfs/libguestfs/issues/139 [2] https://bugzilla.redhat.com/show_bug.cgi?id=2275252

CVSS v3 指标

NVD openEuler
Confidentiality None None
Attack Vector Local Local
CVSS评分 5.5 4.0
Attack Complexity Low High
Privileges Required Low High
Scope Unchanged Unchanged
Integrity None None
User Interaction None None
Availability High None

安全公告

公告名 概要 发布时间
KylinSec-SA-2024-2741 In the Linux kernel, the following vulnerability has been resolved: mm: zswap: fix shrinker NULL crash with cgroup_disable=memory Christian reports a NULL deref in zswap that he bisected down to the zswap shrinker. The issue also cropped up in the bug trackers of libguestfs [1] and the Red Hat bugzilla [2]. The problem is that when memcg is disabled with the boot time flag, the zswap shrinker might get called with sc->memcg == NULL. This is okay in many places, like the lruvec operations. But it crashes in memcg_page_state() - which is only used due to the non-node accounting of cgroup's the zswap memory to begin with. Nhat spotted that the memcg can be NULL in the memcg-disabled case, and I was then able to reproduce the crash locally as well. [1] https://github.com/libguestfs/libguestfs/issues/139 [2] https://bugzilla.redhat.com/show_bug.cgi?id=2275252 2024年6月15日

影响产品

产品 状态
KY3.4-5 kernel Unaffected
KY3.5.2 kernel Unaffected
KY3.5.3 kernel Unaffected
V6 kernel Unaffected