Description
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix bpf_xdp_store_bytes proto for read-only arg
While making some maps in Cilium read-only from the BPF side, we noticed
that the bpf_xdp_store_bytes proto is incorrect. In particular, the
verifier was throwing the following error:
; ret = ctx_store_bytes(ctx, l3_off + offsetof(struct iphdr, saddr),
&nat->address, 4, 0);
635: (79) r1 = *(u64 *)(r10 -144) ; R1=ctx() R10=fp0 fp-144=ctx()
636: (b4) w2 = 26 ; R2=26
637: (b4) w4 = 4 ; R4=4
638: (b4) w5 = 0 ; R5=0
639: (85) call bpf_xdp_store_bytes#190
write into map forbidden, value_size=6 off=0 size=4
nat comes from a BPF_F_RDONLY_PROG map, so R3 is a PTR_TO_MAP_VALUE.
The verifier checks the helper's memory access to R3 in
check_mem_size_reg, as it reaches ARG_CONST_SIZE argument. The third
argument has expected type ARG_PTR_TO_UNINIT_MEM, which includes the
MEM_WRITE flag. The verifier thus checks for a BPF_WRITE access on R3.
Given R3 points to a read-only map, the check fails.
Conversely, ARG_PTR_TO_UNINIT_MEM can also lead to the helper reading
from uninitialized memory.
This patch simply fixes the expected argument type to match that of
bpf_skb_store_bytes.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.18 | 6.1.165 |
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 | 6.18.14-1 | — |
| Debian 13 | linux | 6.12.85-1 | — |
| Debian 12 | linux | 6.1.170-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1026.30 | — |
| Ubuntu 25.10 | linux +8 | No fix yet | — |
| Ubuntu 24.04 LTS | linux | 6.8.0-134.134 | USN-8492-1 |
| Ubuntu 24.04 LTS | linux-aws | 6.8.0-1060.63 | USN-8492-1 |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1063.71 | USN-8606-1 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1062.69 | USN-8607-1 |
| Ubuntu 24.04 LTS | linux-azure-nvidia | 6.8.0-1039.42 | — |
| Ubuntu 24.04 LTS | linux-gcp | 6.8.0-1063.69 | USN-8492-1 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1058.64 | USN-8492-2 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1045.48 | USN-8492-2 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1060.61 | USN-8492-1 |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-134.134.1 | USN-8497-1 |
| Ubuntu 24.04 LTS | linux-nvidia | 6.8.0-1058.61 | USN-8492-1 |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1058.61.1 | USN-8492-2 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1029.30 | USN-8498-1 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1057.58 | USN-8492-1 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1060.64 | USN-8492-4 |
| Ubuntu 24.04 LTS | linux-riscv +26 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-xilinx | 6.8.0-1032.33 | USN-8499-1 |
| Ubuntu 22.04 LTS | linux-aws-6.8 | 6.8.0-1060.63~22.04.1 | USN-8492-2 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1063.71~22.04.1 | USN-8606-1 |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1062.69~22.04.1 | USN-8609-1 |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1063.69~22.04.1 | USN-8492-2 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 | 6.8.0-136.136~22.04.1 | USN-8619-1 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1060.61~22.04.1 | USN-8492-2 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-134.134.1~22.04.1 | USN-8497-1 |
| Ubuntu 22.04 LTS | linux-nvidia-6.8 | 6.8.0-1058.61~22.04.1 | USN-8492-1 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1057.58~22.04.1 | USN-8492-2 |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv-6.8 | 6.8.0-134.134~22.04.1 | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-raspi-realtime | 6.8.0-2049.50 | USN-8492-3 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1055.56 | USN-8492-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 +1 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1055.56~22.04.1 | USN-8492-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1060.63+fips1 | USN-8492-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1062.69+fips1 | USN-8492-5 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-134.134+fips1 | USN-8492-5 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1063.69+fips1 | USN-8492-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +6 | 6.4.0-150700.53.60.1 | SUSE-SU-2026:2482-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.60.1.150700.17.35.4 | SUSE-SU-2026:2482-1 |
| SLES 15 SP7 | kernel-obs-build | 6.4.0-150700.53.60.2 | SUSE-SU-2026:2482-1 |
| SLES 15 SP6 | kernel-64kb +6 | 6.4.0-150600.23.118.1 | SUSE-SU-2026:2632-1 |
| SLES 15 SP6 | kernel-default-base | 6.4.0-150600.23.118.1.150600.12.56.1 | SUSE-SU-2026:2632-1 |
| SLES 15 SP5 | kernel-64kb +4 | 5.14.21-150500.55.172.2 | SUSE-SU-2026:2658-1 |
| SLES 15 SP5 | kernel-default-base | 5.14.21-150500.55.172.2.150500.6.81.2 | SUSE-SU-2026:2658-1 |
| SLES 15 SP5 | kernel-docs +1 | 5.14.21-150500.55.172.1 | SUSE-SU-2026:2658-1 |
Show 13 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +8 | 6.12.0-160000.35.1 | SUSE-SU-2026:22127-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.35.1.160000.2.16 | SUSE-SU-2026:22127-1 |
| SLES for SAP 15 SP6 | kernel-default-base | 6.4.0-150600.23.118.1.150600.12.56.1 | SUSE-SU-2026:2632-1 |
| SLES for SAP 15 SP6 | kernel-docs +4 | 6.4.0-150600.23.118.1 | SUSE-SU-2026:2632-1 |
| SLES for SAP 15 SP5 | kernel-default-base | 5.14.21-150500.55.172.2.150500.6.81.2 | SUSE-SU-2026:2658-1 |
| SLES for SAP 15 SP5 | kernel-docs +1 | 5.14.21-150500.55.172.1 | SUSE-SU-2026:2658-1 |
| SLES for SAP 15 SP5 | kernel-source +2 | 5.14.21-150500.55.172.2 | SUSE-SU-2026:2658-1 |
| SLES 16.0 | kernel-64kb +8 | 6.12.0-160000.35.1 | SUSE-SU-2026:22127-1, SUSE-SU-2026:22099-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.35.1.160000.2.16 | SUSE-SU-2026:22127-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.35.1.160000.2.16 | SUSE-SU-2026:22112-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.35.1 | SUSE-SU-2026:22117-1, SUSE-SU-2026:22112-1 |
| SLE Micro 6.1 | kernel-default-base | 6.4.0-47.1.21.24 | SUSE-SU-2026:22137-1 |
| SLE Micro 6.1 | kernel-rt +1 | 6.4.0-48.1 | SUSE-SU-2026:22458-1 |
| SLE Micro 6.1 | kernel-source +2 | 6.4.0-47.1 | SUSE-SU-2026:22137-1 |
| SLE Micro 6.0 | kernel-default-base | 6.4.0-47.1.21.24 | SUSE-SU-2026:22108-1 |
| SLE Micro 6.0 | kernel-rt +1 | 6.4.0-48.1 | SUSE-SU-2026:22433-1 |
| SLE Micro 6.0 | kernel-source +2 | 6.4.0-47.1 | SUSE-SU-2026:22108-1 |
| SLE Micro 5.5 | kernel-default-base | 5.14.21-150500.55.172.2.150500.6.81.2 | SUSE-SU-2026:2658-1 |
| SLE Micro 5.5 | kernel-rt +1 | 5.14.21-150500.13.146.1 | SUSE-SU-2026:2630-1 |
| SLE Micro 5.5 | kernel-source +1 | 5.14.21-150500.55.172.2 | SUSE-SU-2026:2658-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.60.1 | SUSE-SU-2026:2482-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_16 | 1-150700.1.5.2 | SUSE-SU-2026:2591-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_16 | 1-150700.15.3.2 | SUSE-SU-2026:2482-1 |
| SLE Live Patching 15 SP6 | kernel-default | 6.4.0-150600.23.118.1 | SUSE-SU-2026:2632-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_28 | 1-150600.13.3.1 | SUSE-SU-2026:2632-1 |
| SLE Live Patching 15 SP5 | kernel-default | 5.14.21-150500.55.172.2 | SUSE-SU-2026:2658-1 |
| SLE Live Patching 15 SP5 | kernel-livepatch-SLE15-SP5_Update_42 | 1-150500.11.3.2 | SUSE-SU-2026:2658-1 |
| SLE HPC 15 SP5 | kernel-64kb +3 | 5.14.21-150500.55.172.2 | SUSE-SU-2026:2658-1 |
| SLE HPC 15 SP5 | kernel-default-base | 5.14.21-150500.55.172.2.150500.6.81.2 | SUSE-SU-2026:2658-1 |
| SLE HPC 15 SP5 | kernel-docs +1 | 5.14.21-150500.55.172.1 | SUSE-SU-2026:2658-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt +1 | 6.4.0-150700.7.59.2 | SUSE-SU-2026:2591-1 |
| SUSE Real Time Module 15 SP7 | kernel-syms-rt | 6.4.0-150700.7.59.1 | SUSE-SU-2026:2591-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.35.1.160000.2.16 | openSUSE-SU-2026:20965-1 |
| openSUSE Leap 16.0 | kernel-rt +11 | 6.12.0-160000.35.1 | openSUSE-SU-2026:20965-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.12.77-99.140 +2 | 1:1.0-0.amzn2023 | ALAS2023-2026-1544, ALAS2023-2026-1543, ALAS2023-2026-1514 |
| Amazon Linux 2023 | perf +14 | 1:6.1.166-197.305.amzn2023 | ALAS2023-2026-1544 |
| Amazon Linux 2023 | perf6.12 +14 | 1:6.12.77-99.140.amzn2023 | ALAS2023-2026-1543 |
| Amazon Linux 2023 | perf6.18 +14 | 1:6.18.15-14.217.amzn2023 | ALAS2023-2026-1514 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-204.92.4.2.el10uek | ELSA-2026-50372 |
Advisories 31
- USN-8607-1 linux-azure-fde vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- WID-SEC-2026-1700 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- USN-8606-1 linux-azure, linux-azure-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8619-1 linux-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8609-1 linux-azure-fde-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8499-1 linux-xilinx vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8497-1 linux-lowlatency, linux-lowlatency-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8492-1 linux, linux-aws, linux-aws-fips, linux-gcp, linux-gcp-fips, linux-ibm, linux-nvidia, linux-nvidia-6.8, linux-oracle, linux-realtime, linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8492-2 linux-aws-6.8, linux-gcp-6.8, linux-gke, linux-gkeop, linux-ibm-6.8, linux-nvidia-lowlatency, linux-oracle-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8498-1 linux-nvidia-tegra vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8492-3 linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8492-5 linux-azure-fips, linux-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8492-4 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- SUSE-SU-2026:22117-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 9, 2026
- SUSE-SU-2026:22458-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 4, 2026
- SUSE-SU-2026:22433-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 3, 2026
- ELSA-2026-50372 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jul 2, 2026
- SUSE-SU-2026:2658-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jun 27, 2026
- SUSE-SU-2026:2630-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jun 26, 2026
- SUSE-SU-2026:2632-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jun 26, 2026
- openSUSE-SU-2026:20965-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jun 24, 2026
- SUSE-SU-2026:2591-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jun 24, 2026
- SUSE-SU-2026:2482-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jun 24, 2026
- SUSE-SU-2026:22137-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jun 18, 2026
- SUSE-SU-2026:22127-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jun 17, 2026
- SUSE-SU-2026:22112-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jun 17, 2026
- SUSE-SU-2026:22099-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jun 17, 2026
- SUSE-SU-2026:22108-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jun 17, 2026
- ALAS2023-2026-1514 Important: kernel6.18 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jun 16, 2026
- ALAS2023-2026-1543 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jun 16, 2026
- ALAS2023-2026-1544 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jun 16, 2026
References
- https://git.kernel.org/stable/c/ffb5d1c5e3933b947fc7303ad68bf0c536d0c85e
- https://git.kernel.org/stable/c/ddc34a1b85505c919026ddc82fafdada9a160b15
- https://git.kernel.org/stable/c/0db169a91381a473b7974021d1c02f8da72c5775
- https://git.kernel.org/stable/c/d7b87adeb0eb539b9b824b101bb14fb01e41240b
- https://git.kernel.org/stable/c/57f7f6a0ad04a65c8a7a067b2f56cbbf2aec9e52
- https://git.kernel.org/stable/c/6557f1565d779851c4db9c488c49c05a47a6e72f