Description
In the Linux kernel, the following vulnerability has been resolved:
tcp: fix skb_copy_ubufs() vs BIG TCP
David Ahern reported crashes in skb_copy_ubufs() caused by TCP tx zerocopy
using hugepages, and skb length bigger than ~68 KB.
skb_copy_ubufs() assumed it could copy all payload using up to
MAX_SKB_FRAGS order-0 pages.
This assumption broke when BIG TCP was able to put up to 512 KB per skb.
We did not hit this bug at Google because we use CONFIG_MAX_SKB_FRAGS=45
and limit gso_max_size to 180000.
A solution is to use higher order pages if needed.
v2: add missing __GFP_COMP, or we leak memory.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.19 | 6.1.29 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 6.4.4-1 | — |
| Debian 13 | linux | 6.4.4-1 | — |
| Debian 12 | linux | 6.1.37-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-intel +9 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9 | bpftool | 7.2.0-362.8.1.el9_3 | RHSA-2023:6583 |
| RHEL 9 | rv +64 | 5.14.0-362.8.1.el9_3 | RHSA-2023:6583 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.1.29-47.49 | 1.0-0.amzn2023 | ALAS2023-2023-184 |
| Amazon Linux 2023 | perf +12 | 6.1.29-47.49.amzn2023 | ALAS2023-2023-184 |
Advisories 3
- WID-SEC-2025-2229 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 18, 2026
- RHSA-2023:6583 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- ALAS2023-2023-184 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Feb 11, 2026