ALAS2-2023-2268

Related Vulnerabilities: CVE-2023-4206   CVE-2023-4208  

A use-after-free vulnerability in the Linux kernel's net/sched: cls_route component can be exploited to achieve local privilege escalation. When route4_change() is called on an existing filter, the whole tcf_result struct is always copied into the new instance of the filter. This causes a problem when updating a filter bound to a class, as tcf_unbind_filter() is always called on the old instance in the success path, decreasing filter_cnt of the still referenced class and allowing it to be deleted, leading to a use-after-free. We recommend upgrading past commit b80b829e9e2c1b3f7aae34855e04d8f6ecaf13c8. (CVE-2023-4206) A use-after-free vulnerability in the Linux kernel's net/sched: cls_u32 component can be exploited to achieve local privilege escalation. When u32_change() is called on an existing filter, the whole tcf_result struct is always copied into the new instance of the filter. This causes a problem when updating a filter bound to a class, as tcf_unbind_filter() is always called on the old instance in the success path, decreasing filter_cnt of the still referenced class and allowing it to be deleted, leading to a use-after-free. We recommend upgrading past commit 3044b16e7c6fe5d24b1cdbcf1bd0a9d92d1ebd81. (CVE-2023-4208)

ALAS2-2023-2268


Amazon Linux 2 Security Advisory: ALAS-2023-2268
Advisory Release Date: 2023-09-27 22:48 Pacific
Advisory Updated Date: 2023-10-05 22:02 Pacific
Severity: Important

Issue Overview:

A use-after-free vulnerability in the Linux kernel's net/sched: cls_route component can be exploited to achieve local privilege escalation.

When route4_change() is called on an existing filter, the whole tcf_result struct is always copied into the new instance of the filter. This causes a problem when updating a filter bound to a class, as tcf_unbind_filter() is always called on the old instance in the success path, decreasing filter_cnt of the still referenced class and allowing it to be deleted, leading to a use-after-free.

We recommend upgrading past commit b80b829e9e2c1b3f7aae34855e04d8f6ecaf13c8. (CVE-2023-4206)

A use-after-free vulnerability in the Linux kernel's net/sched: cls_u32 component can be exploited to achieve local privilege escalation.

When u32_change() is called on an existing filter, the whole tcf_result struct is always copied into the new instance of the filter. This causes a problem when updating a filter bound to a class, as tcf_unbind_filter() is always called on the old instance in the success path, decreasing filter_cnt of the still referenced class and allowing it to be deleted, leading to a use-after-free.

We recommend upgrading past commit 3044b16e7c6fe5d24b1cdbcf1bd0a9d92d1ebd81. (CVE-2023-4208)


Affected Packages:

kernel


Issue Correction:
Run yum update kernel to update your system.

New Packages:
aarch64:
    kernel-4.14.322-244.536.amzn2.aarch64
    kernel-headers-4.14.322-244.536.amzn2.aarch64
    kernel-debuginfo-common-aarch64-4.14.322-244.536.amzn2.aarch64
    perf-4.14.322-244.536.amzn2.aarch64
    perf-debuginfo-4.14.322-244.536.amzn2.aarch64
    python-perf-4.14.322-244.536.amzn2.aarch64
    python-perf-debuginfo-4.14.322-244.536.amzn2.aarch64
    kernel-tools-4.14.322-244.536.amzn2.aarch64
    kernel-tools-devel-4.14.322-244.536.amzn2.aarch64
    kernel-tools-debuginfo-4.14.322-244.536.amzn2.aarch64
    kernel-devel-4.14.322-244.536.amzn2.aarch64
    kernel-debuginfo-4.14.322-244.536.amzn2.aarch64

i686:
    kernel-headers-4.14.322-244.536.amzn2.i686

src:
    kernel-4.14.322-244.536.amzn2.src

x86_64:
    kernel-4.14.322-244.536.amzn2.x86_64
    kernel-headers-4.14.322-244.536.amzn2.x86_64
    kernel-debuginfo-common-x86_64-4.14.322-244.536.amzn2.x86_64
    perf-4.14.322-244.536.amzn2.x86_64
    perf-debuginfo-4.14.322-244.536.amzn2.x86_64
    python-perf-4.14.322-244.536.amzn2.x86_64
    python-perf-debuginfo-4.14.322-244.536.amzn2.x86_64
    kernel-tools-4.14.322-244.536.amzn2.x86_64
    kernel-tools-devel-4.14.322-244.536.amzn2.x86_64
    kernel-tools-debuginfo-4.14.322-244.536.amzn2.x86_64
    kernel-devel-4.14.322-244.536.amzn2.x86_64
    kernel-debuginfo-4.14.322-244.536.amzn2.x86_64
    kernel-livepatch-4.14.322-244.536-1.0-0.amzn2.x86_64