Description
In the Linux kernel, the following vulnerability has been resolved:
lib/group_cpus: fix NULL pointer dereference from group_cpus_evenly()
While testing null_blk with configfs, echo 0 > poll_queues will trigger
following panic:
BUG: kernel NULL pointer dereference, address: 0000000000000010
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 27 UID: 0 PID: 920 Comm: bash Not tainted 6.15.0-02023-gadbdb95c8696-dirty #1238 PREEMPT(undef)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014
RIP: 0010:__bitmap_or+0x48/0x70
Call Trace:
<TASK>
__group_cpus_evenly+0x822/0x8c0
group_cpus_evenly+0x2d9/0x490
blk_mq_map_queues+0x1e/0x110
null_map_queues+0xc9/0x170 [null_blk]
blk_mq_update_queue_map+0xdb/0x160
blk_mq_update_nr_hw_queues+0x22b/0x560
nullb_update_nr_hw_queues+0x71/0xf0 [null_blk]
nullb_device_poll_queues_store+0xa4/0x130 [null_blk]
configfs_write_iter+0x109/0x1d0
vfs_write+0x26e/0x6f0
ksys_write+0x79/0x180
__x64_sys_write+0x1d/0x30
x64_sys_call+0x45c4/0x45f0
do_syscall_64+0xa5/0x240
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Root cause is that numgrps is set to 0, and ZERO_SIZE_PTR is returned from
kcalloc(), and later ZERO_SIZE_PTR will be deferenced.
Fix the problem by checking numgrps first in group_cpus_evenly(), and
return NULL directly if numgrps is zero.
[yukuai3@huawei.com: also fix the non-SMP version]
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 6.3 | 6.6.96 |
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 | 6.12.37-1 | — |
| Debian 13 | linux | 6.12.37-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1016.20 | — |
| Ubuntu 25.10 | linux-azure-fde | No fix yet | — |
| Ubuntu 24.04 LTS | linux | 6.8.0-100.100 | USN-8028-1 |
| Ubuntu 24.04 LTS | linux-aws +1 | 6.8.0-1046.49 | USN-8028-5 |
| Ubuntu 24.04 LTS | linux-aws-6.14 +1 | 6.14.0-1015.15~24.04.1 | USN-7833-3, USN-7833-1 |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1046.52 | USN-8074-1 |
| Ubuntu 24.04 LTS | linux-azure-6.14 | 6.14.0-1014.14~24.04.1 | USN-7834-1 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1046.53 | — |
| Ubuntu 24.04 LTS | linux-azure-nvidia | 6.8.0-1039.42 | — |
| Ubuntu 24.04 LTS | linux-azure-nvidia-6.14 | 6.14.0-1007.7 | USN-7834-1 |
| Ubuntu 24.04 LTS | linux-gcp | 6.8.0-1047.50 | USN-8031-3 |
| Ubuntu 24.04 LTS | linux-gcp-6.14 | 6.14.0-1018.19~24.04.1 | USN-7833-4 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1043.48 | USN-8031-3 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1030.33 | USN-8028-5 |
| Ubuntu 24.04 LTS | linux-hwe-6.14 | 6.14.0-34.34~24.04.1 | USN-7856-1 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1044.44 | USN-8028-8 |
| Ubuntu 24.04 LTS | linux-intel +10 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-100.100.1 | USN-8052-1 |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1046.49.1 | USN-8028-7 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1020.20 | — |
| Ubuntu 24.04 LTS | linux-oem-6.14 | 6.14.0-1014.14 | USN-7833-1 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1043.44 | USN-8028-5 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1047.51 | USN-8028-1 |
| Ubuntu 24.04 LTS | linux-riscv-6.14 | 6.14.0-34.34.1~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-xilinx | 6.8.0-1023.24 | USN-8052-2 |
| Ubuntu 22.04 LTS | linux-aws-6.8 +1 | 6.8.0-1046.49~22.04.1 | USN-8028-5 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1051.57~22.04.1 | USN-8126-1 |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1046.53~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1047.50~22.04.2 | USN-8031-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 +1 | 6.8.0-100.100~22.04.1 | USN-8028-6 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1044.44~22.04.1 | USN-8028-8 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-100.100.1~22.04.1 | USN-8028-6 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1043.44~22.04.1 | USN-8028-5 |
| Ubuntu 22.04 LTS | linux-riscv +32 | 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-raspi-realtime | 6.8.0-2037.38 | USN-8028-3 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1041.42 | USN-8028-3 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 | 6.14.0-1014.14~24.04.1 | USN-7833-2 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1041.42~22.04.1 | USN-8028-2 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1046.49+fips1 | USN-8028-4 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1046.52+fips1 | USN-8074-2 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-100.100+fips1 | USN-8028-4 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1047.50+fips1 | USN-8031-2 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +6 | 6.4.0-150700.53.19.1 | SUSE-SU-2025:03601-1 |
| SLES 15 SP7 | kernel-azure +1 | 6.4.0-150700.20.15.2 | SUSE-SU-2025:03633-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.19.1.150700.17.13.1 | SUSE-SU-2025:03601-1 |
| SLES 15 SP7 | kernel-syms-azure | 6.4.0-150700.20.15.1 | SUSE-SU-2025:03633-1 |
| SLES 15 SP6 | kernel-64kb +6 | 6.4.0-150600.23.73.1 | SUSE-SU-2025:03600-1 |
| SLES 15 SP6 | kernel-azure +2 | 6.4.0-150600.8.52.1 | SUSE-SU-2025:03634-1 |
| SLES 15 SP6 | kernel-coco +3 | 6.4.0-15061.32.coco15sp6.1 | SUSE-SU-2025:03602-1 |
| SLES 15 SP6 | kernel-default-base | 6.4.0-150600.23.73.1.150600.12.32.1 | SUSE-SU-2025:03600-1 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +7 | 6.12.0-160000.6.1 | SUSE-SU-2025:21139-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.6.1.160000.2.4 | SUSE-SU-2025:21139-1 |
| SLES 16.0 | kernel-64kb +7 | 6.12.0-160000.6.1 | SUSE-SU-2025:21179-1, SUSE-SU-2025:21139-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.6.1.160000.2.4 | SUSE-SU-2025:21139-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.6.1.160000.2.4 | SUSE-SU-2025:21074-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.6.1 | SUSE-SU-2026:20560-1, SUSE-SU-2025:21074-1 |
| SLE Micro 6.1 | kernel-default-base | 6.4.0-35.1.21.12 | SUSE-SU-2025:20861-1 |
| SLE Micro 6.1 | kernel-rt +1 | 6.4.0-37.1 | SUSE-SU-2025:20898-1 |
| SLE Micro 6.1 | kernel-source +2 | 6.4.0-35.1 | SUSE-SU-2025:20861-1 |
| SLE Micro 6.0 | kernel-default-base | 6.4.0-35.1.21.12 | SUSE-SU-2025:20851-1 |
| SLE Micro 6.0 | kernel-rt +1 | 6.4.0-37.1 | SUSE-SU-2025:20870-1 |
| SLE Micro 6.0 | kernel-source +2 | 6.4.0-35.1 | SUSE-SU-2025:20851-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.19.1 | SUSE-SU-2025:03601-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_5 | 1-150700.1.3.1 | SUSE-SU-2025:3725-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_5 | 1-150700.15.3.1 | SUSE-SU-2025:03601-1 |
| SLE Live Patching 15 SP6 | kernel-default | 6.4.0-150600.23.73.1 | SUSE-SU-2025:03600-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_16 | 1-150600.1.3.1 | SUSE-SU-2025:3751-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_16 | 1-150600.13.3.1 | SUSE-SU-2025:03600-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt +2 | 6.4.0-150700.7.19.1 | SUSE-SU-2025:3725-1 |
| SUSE Real Time Module 15 SP6 | kernel-rt +3 | 6.4.0-150600.10.55.1 | SUSE-SU-2025:3751-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.6.1.160000.2.4 | openSUSE-SU-2025:20081-1 |
| openSUSE Leap 16.0 | kernel-rt +10 | 6.12.0-160000.6.1 | openSUSE-SU-2025:20081-1 |
| openSUSE Leap 15.6 | dtb-aarch64 +10 | 6.4.0-150600.23.73.1 | SUSE-SU-2025:03600-1 |
| openSUSE Leap 15.6 | kernel-azure +2 | 6.4.0-150600.8.52.1 | SUSE-SU-2025:03634-1 |
| openSUSE Leap 15.6 | kernel-default-base | 6.4.0-150600.23.73.1.150600.12.32.1 | SUSE-SU-2025:03600-1 |
| openSUSE Leap 15.6 | kernel-rt +3 | 6.4.0-150600.10.55.1 | SUSE-SU-2025:3751-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.12.37-61.105 | 1:1.0-0.amzn2023 | ALAS2023-2025-1130 |
| Amazon Linux 2023 | perf6.12 +14 | 1:6.12.37-61.105.amzn2023 | ALAS2023-2025-1130 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-103.40.4.1.el10uek | ELSA-2025-20551 |
Advisories 41
- WID-SEC-2025-1517 Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Nov 12, 2026
- USN-8028-5 linux-aws, linux-aws-6.8, linux-gkeop, linux-nvidia, linux-nvidia-6.8, linux-oracle, linux-oracle-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8126-1 linux-azure-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-8 linux-ibm, linux-ibm-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-6 linux-hwe-6.8, linux-lowlatency-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8052-1 linux-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8052-2 linux-xilinx vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8074-1 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8074-2 linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8031-3 linux-gcp, linux-gke vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-1 linux, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-4 linux-aws-fips, linux-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-3 linux-realtime, linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-2 linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-7 linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8031-2 linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8031-1 linux-gcp-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7833-2 linux-realtime-6.14 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7833-1 linux, linux-aws, linux-gcp, linux-oem-6.14, linux-oracle, linux-oracle-6.14, linux-raspi, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7834-1 linux-azure, linux-azure-6.14, linux-azure-nvidia-6.14 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7833-4 linux-gcp-6.14 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7833-3 linux-aws-6.14 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- SUSE-SU-2026:20560-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 9, 2026
- USN-7856-1 linux-hwe-6.14 vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- openSUSE-SU-2025:20081-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21179-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21139-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21074-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20851-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:03634-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20861-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:03602-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20870-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:03600-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:03633-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:03601-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20898-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:3751-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:3725-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- ALAS2023-2025-1130 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Dec 19, 2025
- ELSA-2025-20551 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Sep 8, 2025