Description
In the Linux kernel, the following vulnerability has been resolved:
netfilter: synproxy: Fix out of bounds when parsing TCP options
The TCP option parser in synproxy (synproxy_parse_options) could read
one byte out of bounds. When the length is 1, the execution flow gets
into the loop, reads one byte of the opcode, and if the opcode is
neither TCPOPT_EOL nor TCPOPT_NOP, it reads one more byte, which exceeds
the length of 1.
This fix is inspired by commit 9609dad263f8 ("ipv4: tcp_input: fix stack
out of bounds when parsing TCP options.").
v2 changes:
Added an early return when length < 0 to avoid calling
skb_header_pointer with negative length.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 3.12 | 4.4.274 |
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 | 5.10.46-1 | — |
| Debian 13 | linux | 5.10.46-1 | — |
| Debian 12 | linux | 5.10.46-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-raspi-realtime | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +22 | No fix yet | — |
| Ubuntu 20.04 LTS | linux | 5.4.0-81.91 | — |
| Ubuntu 20.04 LTS | linux-aws | 5.4.0-1055.58 | — |
| Ubuntu 20.04 LTS | linux-azure | 5.4.0-1056.58 | — |
| Ubuntu 20.04 LTS | linux-bluefield | 5.4.0-1019.22 | — |
| Ubuntu 20.04 LTS | linux-gcp | 5.4.0-1051.55 | — |
| Ubuntu 20.04 LTS | linux-gke +26 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gkeop | 5.4.0-1022.23 | — |
| Ubuntu 20.04 LTS | linux-kvm | 5.4.0-1045.47 | — |
| Ubuntu 20.04 LTS | linux-oracle | 5.4.0-1053.57 | — |
| Ubuntu 20.04 LTS | linux-raspi | 5.4.0-1042.46 | — |
| Ubuntu 18.04 LTS | linux | 4.15.0-156.163 | — |
| Ubuntu 18.04 LTS | linux-aws | 4.15.0-1111.118 | — |
| Ubuntu 18.04 LTS | linux-aws-5.4 | 5.4.0-1055.58~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-azure-4.15 | 4.15.0-1123.136 | — |
| Ubuntu 18.04 LTS | linux-azure-5.4 | 5.4.0-1056.58~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp-4.15 | 4.15.0-1108.122 | — |
| Ubuntu 18.04 LTS | linux-gcp-5.4 | 5.4.0-1051.55~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-hwe-5.4 | 5.4.0-81.91~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-kvm | 4.15.0-1099.101 | — |
| Ubuntu 18.04 LTS | linux-oracle | 4.15.0-1080.88 | — |
| Ubuntu 18.04 LTS | linux-oracle-5.4 | 5.4.0-1053.57~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-raspi-5.4 | 5.4.0-1042.46~18.04.3 | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro FIPS 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-aws-fips | 5.4.0-1069.73+fips2 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-azure-fips | 5.4.0-1073.76+fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-fips | 5.4.0-1032.37 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-gcp-fips | 5.4.0-1067.71~20.04.1 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-aws-fips | 4.15.0-2053.55 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-azure-fips | 4.15.0-2035.39 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-fips | 4.15.0-1069.78 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-gcp-fips | 4.15.0-2018.20 | — |
| Ubuntu Pro FIPS-updates 16.04 LTS | linux-fips | 4.4.0-1113.120 | USN-7506-3 |
| Ubuntu Pro 16.04 LTS | linux | 4.4.0-268.302 | USN-7506-1 |
| Ubuntu Pro 16.04 LTS | linux-aws | 4.4.0-1181.196 | USN-7506-1 |
| Ubuntu Pro 16.04 LTS | linux-aws-hwe | 4.15.0-1111.118~16.04.1 | — |
| Ubuntu Pro 16.04 LTS | linux-azure | 4.15.0-1123.136~16.04.1 | — |
| Ubuntu Pro 16.04 LTS | linux-gcp | 4.15.0-1108.122~16.04.1 | — |
| Ubuntu Pro 16.04 LTS | linux-hwe | 4.15.0-156.163~16.04.1 | — |
| Ubuntu Pro 16.04 LTS | linux-kvm | 4.4.0-1144.155 | USN-7506-1 |
| Ubuntu Pro 16.04 LTS | linux-oracle | 4.15.0-1080.88~16.04.1 | — |
| Ubuntu Pro 14.04 LTS | linux | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux-aws | 4.4.0-1143.149 | USN-7506-2 |
| Ubuntu Pro 14.04 LTS | linux-azure | 4.15.0-1123.136~14.04.1 | — |
| Ubuntu Pro 14.04 LTS | linux-lts-xenial | 4.4.0-268.302~14.04.1 | USN-7506-4 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP5 | kernel-azure +2 | 4.12.14-16.188.1 | SUSE-SU-2024:1979-1 |
| SLES 12 SP5 | kernel-docs +4 | 4.12.14-122.219.1 | SUSE-SU-2024:2184-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP5 | kernel-azure +2 | 4.12.14-16.188.1 | SUSE-SU-2024:1979-1 |
| SLES for SAP 12 SP5 | kernel-syms +2 | 4.12.14-122.219.1 | SUSE-SU-2024:2184-1 |
| SLE Real Time 12 SP5 | kernel-rt +3 | 4.12.14-10.188.1 | SUSE-SU-2024:1983-1 |
| SLE Live Patching 12 SP5 | kernel-default | 4.12.14-122.219.1 | SUSE-SU-2024:2184-1 |
| SLE Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_57 | 1-8.3.1 | SUSE-SU-2024:2184-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | kernel-livepatch-4.14.238-182.421 | 1.0-0.amzn2 | ALAS2-2021-1685 |
| Amazon Linux 2 | perf +8 | 4.14.238-182.421.amzn2 | ALAS2-2021-1685 |
Advisories 8
- USN-7506-2 linux-aws vulnerabilities Ubuntu Security Notices (USN) · Oct 30, 2026
- USN-7506-1 linux, linux-aws, linux-kvm vulnerabilities Ubuntu Security Notices (USN) · Oct 30, 2026
- USN-7506-4 linux-lts-xenial vulnerabilities Ubuntu Security Notices (USN) · Oct 30, 2026
- USN-7506-3 linux-fips vulnerabilities Ubuntu Security Notices (USN) · Oct 30, 2026
- SUSE-SU-2024:1979-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:1983-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:2184-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- ALAS2-2021-1685 Important: kernel security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Oct 2, 2025
References
- https://git.kernel.org/stable/c/e1eb98cfeafdd85537e7e3cefe93ca9bfbcc3ea8
- https://git.kernel.org/stable/c/576c1526b4d83c44ad7b673cb841f36cbc6cb6c4
- https://git.kernel.org/stable/c/674b5f0c6a4fc5d3abce877048290cea6091fcb1
- https://git.kernel.org/stable/c/7d9a9a1a88a3da574e019b4de756bc73337b3b0b
- https://git.kernel.org/stable/c/6defc77d48eff74075b80ad5925061b2fc010d98
- https://git.kernel.org/stable/c/9cdf299ba4e153b5e56187648420de22c6216f02
- https://git.kernel.org/stable/c/f648089337cb8ed40b2bb96e244f72b9d97dc96b
- https://git.kernel.org/stable/c/5fc177ab759418c9537433e63301096e733fb915