Description
In the Linux kernel, the following vulnerability has been resolved:
ipv6: ioam: refresh hdr pointer before ioam6_event()
Reported by Sashiko:
In ipv6_hop_ioam(), the hdr pointer is initialized to point into the
skb's linear data buffer. Later, the code calls skb_ensure_writable(),
which might reallocate the buffer:
if (skb_ensure_writable(skb, optoff + 2 + hdr->opt_len))
goto drop;
/* Trace pointer may have changed */
trace = (struct ioam6_trace_hdr *)(skb_network_header(skb)
+ optoff + sizeof(*hdr));
ioam6_fill_trace_data(skb, ns, trace, true);
ioam6_event(IOAM6_EVENT_TRACE, dev_net(skb->dev),
GFP_ATOMIC, (void *)trace, hdr->opt_len - 2);
If the skb is cloned or lacks sufficient linear headroom,
skb_ensure_writable() will invoke pskb_expand_head(), which reallocates
the skb's data buffer and frees the old one, invalidating pointers to
it. While the code recalculates the trace pointer immediately after the
call to skb_ensure_writable(), it fails to recalculate the hdr pointer.
This patch fixes the above by recalculating the hdr pointer before
passing hdr->opt_len to ioam6_event(), so that we avoid any UaF.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 6.9 | 6.12.92 |
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 | 7.0.12-1 | — |
| Debian 13 | linux | 6.12.94-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | linux | 7.0.0-28.28 | — |
| Ubuntu 26.04 LTS | linux-aws +2 | 7.0.0-1009.9 | USN-8618-1, USN-8603-1 |
| Ubuntu 26.04 LTS | linux-gcp +1 | 7.0.0-1008.8 | USN-8593-1 |
| Ubuntu 26.04 LTS | linux-gke | 7.0.0-1003.4 | — |
| Ubuntu 26.04 LTS | linux-ibm +1 | 7.0.0-1010.10 | USN-8603-1, USN-8593-1 |
| Ubuntu 26.04 LTS | linux-nvidia | 7.0.0-1016.16 | USN-8663-1 |
| Ubuntu 26.04 LTS | linux-nvidia-bos | 7.0.0-2016.16 | USN-8664-1 |
| Ubuntu 26.04 LTS | linux-raspi | 7.0.0-1015.15 | USN-8618-1 |
| Ubuntu 26.04 LTS | linux-riscv +1 | 7.0.0-28.28.1 | — |
| Ubuntu 24.04 LTS | linux-azure-7.0 | 7.0.0-1014.14~24.04.1 | USN-8728-2 |
| Ubuntu 24.04 LTS | linux-azure-fde-7.0 | 7.0.0-1013.13~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-gcp-7.0 +1 | 7.0.0-1011.11~24.04.1 | USN-8728-3, USN-8728-1 |
| Ubuntu 24.04 LTS | linux-hwe-7.0 | 7.0.0-28.28~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-nvidia-7.0 | 7.0.0-1016.16~24.04.1 | USN-8663-1 |
| Ubuntu 24.04 LTS | linux-riscv +26 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-riscv-7.0 | 7.0.0-28.28.1~24.04.3 | — |
| 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 | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 +1 | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | rv +77 | 6.12.0-211.63.1.el10_2 | RHSA-2026:76738 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Shadow Migration Toolkit 10 | kernel-modules-internal | 6.12.0-211.63.1.el10_2 | RHSA-2026:76738 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | rv +74 | 6.12.0-211.63.1.el10_2 | ALSA-2026:76738 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +8 | 6.12.0-160000.39.1 | SUSE-SU-2026:24235-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.39.1.160000.2.26 | SUSE-SU-2026:24235-1 |
| SLES 16.0 | kernel-64kb +8 | 6.12.0-160000.39.1 | SUSE-SU-2026:24235-1, SUSE-SU-2026:24197-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.39.1.160000.2.26 | SUSE-SU-2026:24235-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.39.1.160000.2.26 | SUSE-SU-2026:24184-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.39.1 | SUSE-SU-2026:24184-1, SUSE-SU-2026:24179-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.39.1.160000.2.25 | openSUSE-SU-2026:22091-1 |
| openSUSE Leap 16.0 | kernel-rt +11 | 6.12.0-160000.39.1 | openSUSE-SU-2026:22091-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.18.35-68.127 +1 | 1:1.0-0.amzn2023 | ALAS2023-2026-1894, ALAS2023-2026-1881 |
| Amazon Linux 2023 | perf6.12 +11 | 1:6.12.92-122.166.amzn2023 | ALAS2023-2026-1894 |
| Amazon Linux 2023 | perf6.18 +12 | 1:6.18.35-68.127.amzn2023 | ALAS2023-2026-1881 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | rv +29 | 6.12.0-211.63.1.el10_2 | ELSA-2026-76738 |
Advisories 19
- USN-8593-1 linux-ibm, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8663-1 linux-nvidia, linux-nvidia-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8728-1 linux-gcp-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8618-1 linux-aws, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8728-3 linux-oracle-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8728-2 linux-azure-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8603-1 linux-azure, linux-azure-fde vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8664-1 linux-nvidia-bos vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- RHSA-2026:76738 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- WID-SEC-2026-2403 Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff BSI CERT-Bund (WID) · Nov 12, 2026
- ALSA-2026:76738 Important: kernel security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- SUSE-SU-2026:24235-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 21, 2026
- SUSE-SU-2026:24197-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 21, 2026
- SUSE-SU-2026:24184-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 20, 2026
- SUSE-SU-2026:24179-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 20, 2026
- openSUSE-SU-2026:22091-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 19, 2026
- ELSA-2026-76738 Important: kernel security, bug fix, and enhancement update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Oct 8, 2026
- ALAS2023-2026-1881 Important: kernel6.18 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Aug 12, 2026
- ALAS2023-2026-1894 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Aug 6, 2026