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.
[[email protected]: also fix the non-SMP version]
CVSS Details
- CVSS 3.1 Base Score: 5.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon_linux_2023 | — | Upgrade kernel6.12-tools-develUpgrade kernel6.12-toolsUpgrade kernel6.12-headersUpgrade kernel6.12-develUpgrade kernel6.12-tools-debuginfoUpgrade kernel6.12-debuginfoUpgrade perf6.12Upgrade perf6.12-debuginfoUpgrade bpftool6.12Upgrade bpftool6.12-debuginfoUpgrade kernel6.12-debuginfo-common-x86_64Upgrade kernel6.12Upgrade kernel6.12-debuginfo-common-aarch64Upgrade kernel6.12-modules-extraUpgrade python3-perf6.12-debuginfoUpgrade kernel-livepatch-6.12.37-61.105Upgrade kernel6.12-libbpf-debuginfoUpgrade kernel6.12-modules-extra-commonUpgrade kernel6.12-libbpf-develUpgrade kernel6.12-libbpfUpgrade kernel6.12-libbpf-staticUpgrade python3-perf6.12 | Sep 9, 2025 | Jul 9, 2025 |
| Debian | — | Upgrade linux | Jul 23, 2026 | Jul 23, 2026 |
| Redhat_linux | — | No solution exists | Jul 10, 2025 | Jul 9, 2025 |
| Suse | — | Upgrade dtb-armUpgrade dtb-rockchipUpgrade kernel-debug-vdsoUpgrade dtb-amdUpgrade dtb-allwinnerUpgrade dtb-renesasUpgrade reiserfs-kmp-defaultUpgrade kselftests-kmp-defaultUpgrade kselftests-kmp-rtUpgrade dtb-sprdUpgrade reiserfs-kmp-azureUpgrade kernel-azure-vdsoUpgrade kernel-default-baseUpgrade dtb-mediatekUpgrade dtb-socionextUpgrade dlm-kmp-azureUpgrade kernel-defaultUpgrade kernel-azureUpgrade kernel-debug-develUpgrade kernel-rt-extraUpgrade gfs2-kmp-defaultUpgrade dlm-kmp-rtUpgrade dtb-nvidiaUpgrade kernel-obs-buildUpgrade ocfs2-kmp-azureUpgrade kernel-source-vanillaUpgrade kernel-default-livepatch-develUpgrade kernel-rt_debugUpgrade reiserfs-kmp-rtUpgrade kernel-devel-rtUpgrade kernel-syms-rtUpgrade kernel-docsUpgrade kernel-rt-livepatch-develUpgrade kernel-rt-vdsoUpgrade kernel-rt_debug-vdsoUpgrade kernel-rt-develUpgrade kernel-default-base-rebuildUpgrade ocfs2-kmp-defaultUpgrade cluster-md-kmp-64kbUpgrade kernel-64kb-extraUpgrade dlm-kmp-defaultUpgrade kernel-64kbUpgrade dtb-freescaleUpgrade kernel-default-extraUpgrade kernel-64kb-optionalUpgrade kernel-azure-develUpgrade dtb-exynosUpgrade kernel-default-develUpgrade kernel-symsUpgrade kernel-devel-azureUpgrade kernel-sourceUpgrade kernel-64kb-develUpgrade dtb-qcomUpgrade ocfs2-kmp-64kbUpgrade kernel-kvmsmall-develUpgrade kernel-docs-htmlUpgrade kernel-default-livepatchUpgrade kernel-azure-optionalUpgrade kernel-default-optionalUpgrade kernel-macrosUpgrade kernel-kvmsmall-vdsoUpgrade dtb-appleUpgrade dtb-broadcomUpgrade cluster-md-kmp-rtUpgrade dtb-marvellUpgrade kselftests-kmp-azureUpgrade kernel-rt_debug-develUpgrade kernel-debugUpgrade kernel-rt-livepatchUpgrade kernel-obs-qaUpgrade kernel-develUpgrade dtb-amazonUpgrade kernel-syms-azureUpgrade kernel-source-rtUpgrade cluster-md-kmp-azureUpgrade kernel-zfcpdumpUpgrade ocfs2-kmp-rtUpgrade kselftests-kmp-64kbUpgrade dtb-apmUpgrade dlm-kmp-64kbUpgrade kernel-source-azureUpgrade kernel-azure-extraUpgrade gfs2-kmp-rtUpgrade gfs2-kmp-64kbUpgrade dtb-xilinxUpgrade dtb-hisiliconUpgrade kernel-rtUpgrade dtb-caviumUpgrade cluster-md-kmp-defaultUpgrade gfs2-kmp-azureUpgrade dtb-amlogicUpgrade dtb-lgUpgrade kernel-rt-optionalUpgrade reiserfs-kmp-64kbUpgrade kernel-kvmsmallUpgrade dtb-alteraUpgrade kernel-default-vdso | Dec 5, 2025 | Oct 15, 2025 |
| Ubuntu | — | Upgrade linux-image-lowlatency-6.8Upgrade linux-image-aws-64k-6.8Upgrade linux-image-aws-fipsUpgrade linux-image-oracleUpgrade linux-image-6.8.0-1046-aws-fipsUpgrade linux-image-fips-6.8Upgrade linux-image-gcp-6.8Upgrade linux-image-generic-64k-hwe-22.04Upgrade linux-image-6.14.0-1018-gcpUpgrade linux-image-6.8.0-1047-gcp-fipsUpgrade linux-image-6.8.0-1046-nvidia-64kUpgrade linux-image-6.14.0-34-genericUpgrade linux-image-ibm-6.8Upgrade linux-image-oem-22.04dUpgrade linux-image-6.14.0-1014-azureUpgrade linux-image-nvidia-6.8Upgrade linux-image-nvidia-lowlatencyUpgrade linux-image-6.8.0-1046-nvidiaUpgrade linux-image-6.8.0-1046-aws-64kUpgrade linux-image-6.8.0-1046-nvidia-lowlatencyUpgrade linux-image-6.14.0-34-generic-64kUpgrade linux-image-6.8.0-100-generic-64kUpgrade linux-image-oracle-6.14Upgrade linux-image-aws-6.14Upgrade linux-image-generic-6.8Upgrade linux-image-virtualUpgrade linux-image-azure-fipsUpgrade linux-image-6.8.0-100-fipsUpgrade linux-image-generic-64k-6.8Upgrade linux-image-aws-fips-6.8Upgrade linux-image-realtimeUpgrade linux-image-nvidia-lowlatency-64k-6.8Upgrade linux-image-aws-64k-6.14Upgrade linux-image-ibm-lts-24.04Upgrade linux-image-oem-22.04bUpgrade linux-image-lowlatency-hwe-22.04Upgrade linux-image-6.14.0-1015-awsUpgrade linux-image-gcp-64k-lts-24.04Upgrade linux-image-aws-64k-lts-24.04Upgrade linux-image-6.8.0-2037-raspi-realtimeUpgrade linux-image-oem-24.04cUpgrade linux-image-awsUpgrade linux-image-6.14.0-1016-raspiUpgrade linux-image-generic-hwe-22.04Upgrade linux-image-realtime-6.14Upgrade linux-image-kvmUpgrade linux-image-generic-hwe-24.04Upgrade linux-image-nvidia-64k-6.8Upgrade linux-image-6.8.0-1043-oracle-64kUpgrade linux-image-generic-64k-6.14Upgrade linux-image-gcp-64k-6.8Upgrade linux-image-generic-64k-hwe-24.04Upgrade linux-image-azure-nvidia-6.14Upgrade linux-image-lowlatency-64k-6.8Upgrade linux-image-aws-lts-24.04Upgrade linux-image-oem-6.14Upgrade linux-image-6.8.0-1030-gkeopUpgrade linux-image-nvidia-lowlatency-64kUpgrade linux-image-oem-24.04bUpgrade linux-image-nvidia-hwe-22.04Upgrade linux-image-6.14.0-1015-oracleUpgrade linux-image-gcp-lts-24.04Upgrade linux-image-6.8.0-1043-gke-64kUpgrade linux-image-6.8.0-1047-gcp-64kUpgrade linux-image-6.8.1-1041-realtimeUpgrade linux-image-6.14.0-1015-aws-64kUpgrade linux-image-lowlatency-64k-hwe-22.04Upgrade linux-image-ibmUpgrade linux-image-oracle-64k-6.8Upgrade linux-image-oracle-64kUpgrade linux-image-6.8.0-100-genericUpgrade linux-image-raspi-realtimeUpgrade linux-image-oracle-64k-lts-24.04Upgrade linux-image-virtual-6.14Upgrade linux-image-azure-lts-24.04Upgrade linux-image-gkeop-6.8Upgrade linux-image-6.8.0-1043-oracleUpgrade linux-image-realtime-hwe-22.04Upgrade linux-image-raspi-6.14Upgrade linux-image-gcp-6.14Upgrade linux-image-virtual-hwe-22.04Upgrade linux-image-lowlatencyUpgrade linux-image-6.8.0-1051-azureUpgrade linux-image-oem-24.04Upgrade linux-image-lowlatency-64kUpgrade linux-image-oracle-64k-6.14Upgrade linux-image-oem-22.04aUpgrade linux-image-gke-64kUpgrade linux-image-raspiUpgrade linux-image-6.14.0-1018-gcp-64kUpgrade linux-image-azure-6.14Upgrade linux-image-oem-22.04Upgrade linux-image-gkeUpgrade linux-image-realtime-hwe-24.04Upgrade linux-image-generic-6.14Upgrade linux-image-6.8.0-1046-awsUpgrade linux-image-6.8.0-1047-gcpUpgrade linux-image-nvidiaUpgrade linux-image-ibm-classicUpgrade linux-image-gke-64k-6.8Upgrade linux-image-6.8.0-1043-gkeUpgrade linux-image-nvidia-64kUpgrade linux-image-fipsUpgrade linux-image-generic-64kUpgrade linux-image-6.8.0-1047-raspiUpgrade linux-image-raspi-realtime-6.8Upgrade linux-image-intel-iot-realtimeUpgrade linux-image-gcp-fipsUpgrade linux-image-6.14.0-1015-oracle-64kUpgrade linux-image-6.14.0-1014-realtimeUpgrade linux-image-intel-iotgUpgrade linux-image-gcp-fips-6.8Upgrade linux-image-gcp-64k-6.14Upgrade linux-image-6.8.0-1046-nvidia-lowlatency-64kUpgrade linux-image-6.8.0-1046-azure-fipsUpgrade linux-image-6.8.0-100-lowlatency-64kUpgrade linux-image-oem-24.04aUpgrade linux-image-6.14.0-1007-azure-nvidiaUpgrade linux-image-6.8.0-1023-xilinxUpgrade linux-image-aws-6.8Upgrade linux-image-6.8.0-1046-azureUpgrade linux-image-6.8.0-1044-ibmUpgrade linux-image-oracle-lts-24.04Upgrade linux-image-6.14.0-1014-oemUpgrade linux-image-xilinx-6.8Upgrade linux-image-virtual-hwe-24.04Upgrade linux-image-oracle-6.8Upgrade linux-image-gcp-64kUpgrade linux-image-gcpUpgrade linux-image-oem-22.04cUpgrade linux-image-gkeopUpgrade linux-image-xilinx-zynqmpUpgrade linux-image-generic-lpaeUpgrade linux-image-xilinxUpgrade linux-image-virtual-6.8Upgrade linux-image-nvidia-lowlatency-6.8Upgrade linux-image-gke-6.8Upgrade linux-image-azure-fips-6.8Upgrade linux-image-azureUpgrade linux-image-6.8.0-100-lowlatencyUpgrade linux-image-genericUpgrade linux-image-realtime-6.8.1Upgrade linux-image-aws-64kUpgrade linux-image-raspi-6.8Upgrade linux-image-azure-6.8Upgrade linux-image-azure-nvidiaUpgrade linux-image-nvidia-64k-hwe-22.04 | Jul 14, 2025 | Jul 9, 2025 |
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