Description
In the Linux kernel, the following vulnerability has been resolved:
mlx5: Fix default values in create CQ
Currently, CQs without a completion function are assigned the
mlx5_add_cq_to_tasklet function by default. This is problematic since
only user CQs created through the mlx5_ib driver are intended to use
this function.
Additionally, all CQs that will use doorbells instead of polling for
completions must call mlx5_cq_arm. However, the default CQ creation flow
leaves a valid value in the CQ's arm_db field, allowing FW to send
interrupts to polling-only CQs in certain corner cases.
These two factors would allow a polling-only kernel CQ to be triggered
by an EQ interrupt and call a completion function intended only for user
CQs, causing a null pointer exception.
Some areas in the driver have prevented this issue with one-off fixes
but did not address the root cause.
This patch fixes the described issue by adding defaults to the create CQ
flow. It adds a default dummy completion function to protect against
null pointer exceptions, and it sets an invalid command sequence number
by default in kernel CQs to prevent the FW from sending an interrupt to
the CQ until it is armed. User CQs are responsible for their own
initialization values.
Callers of mlx5_core_create_cq are responsible for changing the
completion function and arming the CQ per their needs.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 6.0 | 6.1.191 |
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 | 6.17.9-1 | — |
| Debian 13 | linux | 6.12.115-2 | — |
| Debian 12 | linux | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | No fix yet | — |
| Ubuntu 25.10 | linux | 6.17.0-14.14 | USN-8029-1 |
| Ubuntu 25.10 | linux-aws +2 | 6.17.0-1007.7 | USN-8030-1, USN-8029-2 |
| Ubuntu 25.10 | linux-azure +1 | 6.17.0-1008.8 | USN-8029-3, USN-8029-1 |
| Ubuntu 25.10 | linux-azure-fde | No fix yet | — |
| Ubuntu 25.10 | linux-realtime | 6.17.0-1006.7 | USN-8029-1 |
| Ubuntu 25.10 | linux-riscv | 6.17.0-14.14.1 | — |
| Ubuntu 24.04 LTS | linux +36 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-aws-6.17 +1 | 6.17.0-1007.7~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-gcp-6.17 | 6.17.0-1008.8~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-nvidia-6.17 | 6.17.0-1008.8 | — |
| Ubuntu 24.04 LTS | linux-oem-6.17 | 6.17.0-1011.11 | USN-8048-1 |
| Ubuntu 22.04 LTS | linux-riscv +42 | No fix yet | — |
| 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-realtime +2 | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.17 | 6.17.0-1006.7~24.04.1 | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | No fix yet | — |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips +3 | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +6 | 6.4.0-150700.53.28.1 | SUSE-SU-2026:0315-1 |
| SLES 15 SP7 | kernel-azure +2 | 6.4.0-150700.20.24.1 | SUSE-SU-2026:0281-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.28.1.150700.17.19.1 | SUSE-SU-2026:0315-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +8 | 6.12.0-160000.9.1 | SUSE-SU-2026:20220-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.9.1.160000.2.6 | SUSE-SU-2026:20220-1 |
| SLES 16.0 | kernel-64kb +8 | 6.12.0-160000.9.1 | SUSE-SU-2026:20228-1, SUSE-SU-2026:20220-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.9.1.160000.2.6 | SUSE-SU-2026:20220-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.9.1.160000.2.6 | SUSE-SU-2026:20207-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.9.1 | SUSE-SU-2026:20564-1, SUSE-SU-2026:20207-1 |
| SLE Micro 6.1 | kernel-default-base | 6.4.0-39.1.21.16 | SUSE-SU-2026:20498-1 |
| SLE Micro 6.1 | kernel-rt +1 | 6.4.0-40.1 | SUSE-SU-2026:20876-1 |
| SLE Micro 6.1 | kernel-source +2 | 6.4.0-39.1 | SUSE-SU-2026:20498-1 |
| SLE Micro 6.0 | kernel-default-base | 6.4.0-39.1.21.16 | SUSE-SU-2026:20477-1 |
| SLE Micro 6.0 | kernel-rt +1 | 6.4.0-40.1 | SUSE-SU-2026:20845-1 |
| SLE Micro 6.0 | kernel-source +2 | 6.4.0-39.1 | SUSE-SU-2026:20477-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.28.1 | SUSE-SU-2026:0315-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_8 | 1-150700.1.3.1 | SUSE-SU-2026:0278-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_8 | 1-150700.15.3.1 | SUSE-SU-2026:0315-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt +2 | 6.4.0-150700.7.28.1 | SUSE-SU-2026:0278-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.9.1.160000.2.6 | openSUSE-SU-2026:20145-1 |
| openSUSE Leap 16.0 | kernel-rt +11 | 6.12.0-160000.9.1 | openSUSE-SU-2026:20145-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kernel | 6.6.161.1-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-107.59.3.4.el10uek | ELSA-2026-50372, ELSA-2026-50112, ELSA-2026-50094 |
| Oracle Linux 8 | bpftool +18 | 5.15.0-316.196.4.2.el9uek | ELSA-2026-50113, ELSA-2026-50095 |
Advisories 23
- WID-SEC-2025-2868 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- USN-8029-2 linux-aws, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8048-1 linux-oem-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8029-3 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8030-1 linux-gcp vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8029-1 linux, linux-raspi, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- SUSE-SU-2026:20564-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 9, 2026
- ELSA-2026-50372 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jul 2, 2026
- SUSE-SU-2026:20876-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 31, 2026
- SUSE-SU-2026:20845-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 28, 2026
- openSUSE-SU-2026:20145-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20498-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20477-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20228-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20207-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20220-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0281-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0278-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0315-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- ELSA-2026-50112 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Feb 20, 2026
- ELSA-2026-50113 Important: Unbreakable Enterprise kernel security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Feb 15, 2026
- ELSA-2026-50094 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Feb 6, 2026
- ELSA-2026-50095 Important: Unbreakable Enterprise kernel security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Feb 6, 2026
References
- https://git.kernel.org/stable/c/5c08079c3e5a3c1573afcb5643b5d296865d1170
- https://git.kernel.org/stable/c/1a7865e3e4de2830d8a9fe8c273dc10b248b7338
- https://git.kernel.org/stable/c/a39d334c9840705af69f0466f8f0129c366004ca
- https://git.kernel.org/stable/c/08469f5393a1a39f26a6e2eb2e8c33187665c1f4
- https://git.kernel.org/stable/c/e5eba42f01340f73888dfe560be2806057c25913