PT-2025-8274 · Linux+2 · Linux Kernel+2

Syzbot · Published 2022-06-08 · Updated 2025-09-29 · CVE-2022-49340

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A vulnerability in the Linux kernel has been resolved. The issue is related to the ip gre module, where the GRE protocol with TUNNEL CSUM applies local checksum offload on CHECKSUM PARTIAL packets. The function ipgre xmit must validate csum start after an optional skb pull to prevent an overflow. The original check had false positives when skb checksum start is undefined. The revised check restricts the validation to the branch where it is needed and tests skb transport header, which is set along with csum start in the normal header ops datapath. However, skbs can arrive in this branch without the transport header set, for example, through BPF redirection. The check has been revised to check csum start directly, but only if CHECKSUM PARTIAL.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Buffer Overflow

Weakness Enumeration

CWE-120

Related Identifiers

ALSA-2025_16880

BDU:2026-04038

CVE-2022-49340

RHSA-2022:8267

RHSA-2022_8267

Affected Products

Astra Linux

Linux Kernel

Red Hat

References · 28

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49340.json · Exploit
• https://git.kernel.org/stable/c/fbeb8dfa8b87ef259eef0c89e39b53962a3cf604 · Patch
• https://osv.dev/vulnerability/UBUNTU-CVE-2022-49340 · Vendor Advisory
• https://git.kernel.org/stable/c/e6b6f98fc7605c06c0a3baa70f62c534d7b4ce58 · Patch
• https://git.kernel.org/stable/c/3d08bc3a5d9b2106f5c8bcf1adb73147824aa006 · Patch
• https://git.kernel.org/stable/c/7596bd7920985f7fc8579a92e48bc53ce4475b21 · Patch
• https://osv.dev/vulnerability/DEBIAN-CVE-2022-49340 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2022-49340 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2022-49340 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2022-49340 · Security Note
• https://git.kernel.org/stable/c/0c92d813c7c9ca2212ecd879232e7d87362fce98 · Patch
• https://bdu.fstec.ru/vul/2026-04038 · Security Note
• https://ubuntu.com/security/CVE-2022-49340 · Vendor Advisory
• https://git.kernel.org/stable/c/8d21e9963bec1aad2280cdd034c8993033ef2948 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2022-49340 · Security Note