Incorrect calculation in Linux kernel - CVE-2021-31440

Vulnerability identifier: #VU64201

CSH Severity: Low

CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2021-31440

CWE-ID: CWE-682

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to out-of-bounds access flaw in the Linux kernel’s implementation of the eBPF code verifier, where an incorrect register bounds calculation while checking unsigned 32-bit instructions in an eBPF program occurs. A local user can use this flaw to crash the system or possibly escalate their privileges on the system.

Linux kernel
Red Hat Enterprise Linux for Real Time
Red Hat Enterprise Linux for Real Time for NFV
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
Red Hat CodeReady Linux Builder for x86_64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for ARM 64
SUSE Linux Enterprise Module for Live Patching
Ubuntu
kernel (Red Hat package)
kernel-rt (Red Hat package)
linux-image-generic-64k (Ubuntu package)
linux-image-lowlatency (Ubuntu package)
linux-image-generic-lpae (Ubuntu package)
linux-image-generic (Ubuntu package)
linux-image-virtual (Ubuntu package)
linux-image-5.8.0-59-generic (Ubuntu package)
linux-image-5.8.0-59-lowlatency (Ubuntu package)
linux-image-5.8.0-59-generic-lpae (Ubuntu package)
linux-image-5.8.0-59-generic-64k (Ubuntu package)
linux-image-generic-hwe-20.04 (Ubuntu package)
linux-image-virtual-hwe-20.04 (Ubuntu package)
linux-image-generic-lpae-hwe-20.04 (Ubuntu package)
linux-image-generic-64k-hwe-20.04 (Ubuntu package)
linux-image-lowlatency-hwe-20.04 (Ubuntu package)
linux-image-raspi-nolpae (Ubuntu package)
linux-image-raspi (Ubuntu package)
linux-image-5.8.0-1029-raspi-nolpae (Ubuntu package)
linux-image-5.8.0-1029-raspi (Ubuntu package)
linux-image-5.8.0-1030-kvm (Ubuntu package)
linux-image-kvm (Ubuntu package)
linux-image-oracle (Ubuntu package)
linux-image-5.8.0-1033-oracle (Ubuntu package)
linux-image-gcp (Ubuntu package)
linux-image-gke (Ubuntu package)
linux-image-5.8.0-1035-gcp (Ubuntu package)
linux-image-azure (Ubuntu package)
linux-image-5.8.0-1036-azure (Ubuntu package)
linux-image-5.8.0-1038-aws (Ubuntu package)
linux-image-aws (Ubuntu package)
kernel-livepatch-5_3_18-57-default-debuginfo
kernel-livepatch-SLE15-SP3_Update_0-debugsource
kernel-livepatch-5_3_18-57-default
Pixel

Install updates from vendor's website.

Linux kernel - update to 5.13 rc1
kernel (Red Hat package) - update to 4.18.0-348.el8
kernel-rt (Red Hat package) - update to 4.18.0-348.rt7.130.el8
linux-image-generic-64k (Ubuntu package) - update to 5.8.0.59.64
linux-image-lowlatency (Ubuntu package) - update to 5.8.0.59.64
linux-image-generic-lpae (Ubuntu package) - update to 5.8.0.59.64
linux-image-generic (Ubuntu package) - update to 5.8.0.59.64
linux-image-virtual (Ubuntu package) - update to 5.8.0.59.64
linux-image-5.8.0-59-generic (Ubuntu package) - update to 5.8.0-59.66~20.04.1
linux-image-5.8.0-59-lowlatency (Ubuntu package) - update to 5.8.0-59.66~20.04.1
linux-image-5.8.0-59-generic-lpae (Ubuntu package) - update to 5.8.0-59.66~20.04.1
linux-image-5.8.0-59-generic-64k (Ubuntu package) - update to 5.8.0-59.66~20.04.1
linux-image-generic-hwe-20.04 (Ubuntu package) - update to 5.8.0.59.66~20.04.42
linux-image-virtual-hwe-20.04 (Ubuntu package) - update to 5.8.0.59.66~20.04.42
linux-image-generic-lpae-hwe-20.04 (Ubuntu package) - update to 5.8.0.59.66~20.04.42
linux-image-generic-64k-hwe-20.04 (Ubuntu package) - update to 5.8.0.59.66~20.04.42
linux-image-lowlatency-hwe-20.04 (Ubuntu package) - update to 5.8.0.59.66~20.04.42
linux-image-raspi-nolpae (Ubuntu package) - update to 5.8.0.1029.31
linux-image-raspi (Ubuntu package) - update to 5.8.0.1029.31
linux-image-5.8.0-1029-raspi-nolpae (Ubuntu package) - update to 5.8.0-1029.32
linux-image-5.8.0-1029-raspi (Ubuntu package) - update to 5.8.0-1029.32
linux-image-5.8.0-1030-kvm (Ubuntu package) - update to 5.8.0-1030.32
linux-image-kvm (Ubuntu package) - update to 5.8.0.1030.32
linux-image-oracle (Ubuntu package) - addressed in versions 5.8.0.1033.32, 5.8.0.1033.34~20.04.9
linux-image-5.8.0-1033-oracle (Ubuntu package) - update to 5.8.0-1033.34~20.04.1
linux-image-gcp (Ubuntu package) - addressed in versions 5.8.0.1035.35, 5.8.0.1035.37~20.04.9
linux-image-gke (Ubuntu package) - update to 5.8.0.1035.35
linux-image-5.8.0-1035-gcp (Ubuntu package) - update to 5.8.0-1035.37~20.04.1
linux-image-azure (Ubuntu package) - addressed in versions 5.8.0.1036.36, 5.8.0.1036.38~20.04.8
linux-image-5.8.0-1036-azure (Ubuntu package) - update to 5.8.0-1036.38~20.04.1
linux-image-5.8.0-1038-aws (Ubuntu package) - update to 5.8.0-1038.40~20.04.1
linux-image-aws (Ubuntu package) - update to 5.8.0.1038.40~20.04.11
kernel-livepatch-5_3_18-57-default-debuginfo - update to 7-3.1
kernel-livepatch-SLE15-SP3_Update_0-debugsource - update to 7-3.1
kernel-livepatch-5_3_18-57-default - update to 7-3.1
Pixel - update to 12L 2022-06-05

• https://www.zerodayinitiative.com/advisories/ZDI-21-503/
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=10bf4e83167cc68595b85fd73bb91e8f2c086e36
• https://security.netapp.com/advisory/ntap-20210706-0003/
• https://bugzilla.redhat.com/show_bug.cgi?id=1964028

• Multiple vulnerabilities in Google Pixel
• Red Hat Enterprise Linux 8 update for kernel-rt
• Red Hat Enterprise Linux 8 update for kernel
• SUSE update for the Linux Kernel (Live Patch 0 for SLE 15 SP3)
• Ubuntu update for linux