CVE-2022-49340
ip_gre: test csum_start instead of transport header
- Published
- Updated
- Reserved
- Assigned by
- Linux
Description
In the Linux kernel, the following vulnerability has been resolved: ip_gre: test csum_start instead of transport header GRE with TUNNEL_CSUM will apply local checksum offload on CHECKSUM_PARTIAL packets. ipgre_xmit must validate csum_start after an optional skb_pull, else lco_csum may trigger an overflow. The original check was if (csum && skb_checksum_start(skb) < skb->data) return -EINVAL; This had false positives when skb_checksum_start is undefined: when ip_summed is not CHECKSUM_PARTIAL. A discussed refinement was straightforward if (csum && skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_start(skb) < skb->data) return -EINVAL; But was eventually revised more thoroughly: - restrict the check to the only branch where needed, in an uncommon GRE path that uses header_ops and calls skb_pull. - test skb_transport_header, which is set along with csum_start in skb_partial_csum_set in the normal header_ops datapath. Turns out skbs can arrive in this branch without the transport header set, e.g., through BPF redirection. Revise the check back to check csum_start directly, and only if CHECKSUM_PARTIAL. Do leave the check in the updated location. Check field regardless of whether TUNNEL_CSUM is configured.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.1 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H |
| NVDNVD · Modified | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.28% · top 79% of all CVEs (7 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.1.
Affected products
- affected 774430026bd9a472d08c5d3c33351a782315771a – < 7596bd7920985f7fc8579a92e48bc53ce4475b21
- affected 3d32ce5472bb2ca720bef84089b85f76a705fd1a – < 3d08bc3a5d9b2106f5c8bcf1adb73147824aa006
- affected 87b34cd6485192777f632f92d592f2a71d8801a6 – < fbeb8dfa8b87ef259eef0c89e39b53962a3cf604
- affected 8a0ed250f911da31a2aef52101bc707846a800ff – < e6b6f98fc7605c06c0a3baa70f62c534d7b4ce58
- affected 8a0ed250f911da31a2aef52101bc707846a800ff – < 0c92d813c7c9ca2212ecd879232e7d87362fce98
- affected 8a0ed250f911da31a2aef52101bc707846a800ff – < 0ffa268724656633af5f37a38c212326d98ebe8c
- affected 8a0ed250f911da31a2aef52101bc707846a800ff – < 8d21e9963bec1aad2280cdd034c8993033ef2948
- affected 4bf5d5224ffca069df4501ba5fcc6ded9c002ead
- affected 4.19.207 – < 4.19.247
- affected 5.4.148 – < 5.4.198
- affected 5.10.68 – < 5.10.122
- affected 5.14.7 – < 5.15
- affected 5.15
- unaffected < 5.15
- unaffected 4.19.247 – ≤ 4.19.*
- unaffected 5.4.198 – ≤ 5.4.*
- unaffected 5.10.122 – ≤ 5.10.*
- unaffected 5.15.47 – ≤ 5.15.*
- unaffected 5.17.15 – ≤ 5.17.*
- unaffected 5.18.4 – ≤ 5.18.*
- unaffected 5.19 – ≤ *
References (7)
- https://git.kernel.org/stable/c/7596bd7920985f7fc8579a92e48bc53ce4475b21 (opens in a new tab)
- https://git.kernel.org/stable/c/3d08bc3a5d9b2106f5c8bcf1adb73147824aa006 (opens in a new tab)
- https://git.kernel.org/stable/c/fbeb8dfa8b87ef259eef0c89e39b53962a3cf604 (opens in a new tab)
- https://git.kernel.org/stable/c/e6b6f98fc7605c06c0a3baa70f62c534d7b4ce58 (opens in a new tab)
- https://git.kernel.org/stable/c/0c92d813c7c9ca2212ecd879232e7d87362fce98 (opens in a new tab)
- https://git.kernel.org/stable/c/0ffa268724656633af5f37a38c212326d98ebe8c (opens in a new tab)
- https://git.kernel.org/stable/c/8d21e9963bec1aad2280cdd034c8993033ef2948 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://trackcve.app/cve/CVE-2022-49340)Record last updated .