[ALAS-2023-1827] Amazon Linux AMI 2014.03 - ALAS-2023-1827: important priority package update for kernel

Package updates are available for Amazon Linux AMI that fix the following vulnerabilities:
CVE-2023-4208:
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-2023-4206:
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-2023-4128:
A use-after-free flaw was found in net/sched/cls_fw.c in classifiers (cls_fw, cls_u32, and cls_route) in the Linux Kernel. This flaw allows a local attacker to perform a local privilege escalation due to incorrect handling of the existing filter, leading to a kernel information leak issue.

CVE-2023-34319:
A buffer overrun vulnerability was found in the netback driver in Xen due to an unusual split packet. This flaw allows an unprivileged guest to cause a denial of service (DoS) of the host by sending network packets to the backend, causing the backend to crash.

CVE-2023-3390:
A use-after-free vulnerability was found in the Linux kernel's netfilter subsystem in net/netfilter/nf_tables_api.c.

Mishandled error handling with NFT_MSG_NEWRULE makes it possible to use a dangling pointer in the same transaction causing a use-after-free vulnerability. This flaw allows a local attacker with user access to cause a privilege escalation issue.

We recommend upgrading past commit 1240eb93f0616b21c675416516ff3d74798fdc97.