Important: kernel

Issue Overview:

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

If tcf_change_indev() fails, u32_set_parms() will immediately return an error after incrementing or decrementing the reference counter in tcf_bind_filter(). If an attacker can control the reference counter and set it to zero, they can cause the reference to be freed, leading to a use-after-free vulnerability.

We recommend upgrading past commit 04c55383fa5689357bcdd2c8036725a55ed632bc. (CVE-2023-3609)

An out-of-bounds write vulnerability in the Linux kernel’s net/sched: sch_qfq component can be exploited to achieve local privilege escalation.

The qfq_change_agg() function in net/sched/sch_qfq.c allows an out-of-bounds write because lmax is updated according to packet sizes without bounds checks.

We recommend upgrading past commit 3e337087c3b5805fe0b8a46ba622a962880b5d64. (CVE-2023-3611)

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

If tcf_change_indev() fails, fw_set_parms() will immediately return an error after incrementing or decrementing the reference counter in tcf_bind_filter(). If an attacker can control the reference counter and set it to zero, they can cause the reference to be freed, leading to a use-after-free vulnerability.

We recommend upgrading past commit 0323bce598eea038714f941ce2b22541c46d488f. (CVE-2023-3776)

Affected Packages:

kernel

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

New Packages:

aarch64:  
    kernel-4.14.320-243.544.amzn2.aarch64  
    kernel-headers-4.14.320-243.544.amzn2.aarch64  
    kernel-debuginfo-common-aarch64-4.14.320-243.544.amzn2.aarch64  
    perf-4.14.320-243.544.amzn2.aarch64  
    perf-debuginfo-4.14.320-243.544.amzn2.aarch64  
    python-perf-4.14.320-243.544.amzn2.aarch64  
    python-perf-debuginfo-4.14.320-243.544.amzn2.aarch64  
    kernel-tools-4.14.320-243.544.amzn2.aarch64  
    kernel-tools-devel-4.14.320-243.544.amzn2.aarch64  
    kernel-tools-debuginfo-4.14.320-243.544.amzn2.aarch64  
    kernel-devel-4.14.320-243.544.amzn2.aarch64  
    kernel-debuginfo-4.14.320-243.544.amzn2.aarch64  
  
i686:  
    kernel-headers-4.14.320-243.544.amzn2.i686  
  
src:  
    kernel-4.14.320-243.544.amzn2.src  
  
x86_64:  
    kernel-4.14.320-243.544.amzn2.x86_64  
    kernel-headers-4.14.320-243.544.amzn2.x86_64  
    kernel-debuginfo-common-x86_64-4.14.320-243.544.amzn2.x86_64  
    perf-4.14.320-243.544.amzn2.x86_64  
    perf-debuginfo-4.14.320-243.544.amzn2.x86_64  
    python-perf-4.14.320-243.544.amzn2.x86_64  
    python-perf-debuginfo-4.14.320-243.544.amzn2.x86_64  
    kernel-tools-4.14.320-243.544.amzn2.x86_64  
    kernel-tools-devel-4.14.320-243.544.amzn2.x86_64  
    kernel-tools-debuginfo-4.14.320-243.544.amzn2.x86_64  
    kernel-devel-4.14.320-243.544.amzn2.x86_64  
    kernel-debuginfo-4.14.320-243.544.amzn2.x86_64  
    kernel-livepatch-4.14.320-243.544-1.0-0.amzn2.x86_64  

Additional References

Red Hat: CVE-2023-3609, CVE-2023-3611, CVE-2023-3776

Mitre: CVE-2023-3609, CVE-2023-3611, CVE-2023-3776