In the Linux kernel, the following vulnerability has been resolved:
net: better track kernel sockets lifetime
While kernel sockets are dismantled during pernet_operations->exit(), their freeing can be delayed by any tx packets still held in qdisc or device queues, due to skb_set_owner_w() prior calls.
This then trigger the following warning from ref_tracker_dir_exit() [1]
To fix this, make sure that kernel sockets own a reference on net->passive.
Add sk_net_refcnt_upgrade() helper, used whenever a kernel socket is converted to a refcounted one.
[1]
[ 136.263918][ T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at [ 136.263918][ T35] sk_alloc+0x2b3/0x370 [ 136.263918][ T35] inet6_create+0x6ce/0x10f0 [ 136.263918][ T35] __sock_create+0x4c0/0xa30 [ 136.263918][ T35] inet_ctl_sock_create+0xc2/0x250 [ 136.263918][ T35] igmp6_net_init+0x39/0x390 [ 136.263918][ T35] ops_init+0x31e/0x590 [ 136.263918][ T35] setup_net+0x287/0x9e0 [ 136.263918][ T35] copy_net_ns+0x33f/0x570 [ 136.263918][ T35] create_new_namespaces+0x425/0x7b0 [ 136.263918][ T35] unshare_nsproxy_namespaces+0x124/0x180 [ 136.263918][ T35] ksys_unshare+0x57d/0xa70 [ 136.263918][ T35] __x64_sys_unshare+0x38/0x40 [ 136.263918][ T35] do_syscall_64+0xf3/0x230 [ 136.263918][ T35] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 136.263918][ T35] [ 136.343488][ T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at [ 136.343488][ T35] sk_alloc+0x2b3/0x370 [ 136.343488][ T35] inet6_create+0x6ce/0x10f0 [ 136.343488][ T35] __sock_create+0x4c0/0xa30 [ 136.343488][ T35] inet_ctl_sock_create+0xc2/0x250 [ 136.343488][ T35] ndisc_net_init+0xa7/0x2b0 [ 136.343488][ T35] ops_init+0x31e/0x590 [ 136.343488][ T35] setup_net+0x287/0x9e0 [ 136.343488][ T35] copy_net_ns+0x33f/0x570 [ 136.343488][ T35] create_new_namespaces+0x425/0x7b0 [ 136.343488][ T35] unshare_nsproxy_namespaces+0x124/0x180 [ 136.343488][ T35] ksys_unshare+0x57d/0xa70 [ 136.343488][ T35] __x64_sys_unshare+0x38/0x40 [ 136.343488][ T35] do_syscall_64+0xf3/0x230 [ 136.343488][ T35] entry_SYSCALL_64_after_hwframe+0x77/0x7f
CVSS Details
- CVSS 3.1 Base Score: 7.8
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon_linux_2023 | — | Upgrade kernel-tools-debuginfoUpgrade kernel6.12-debuginfo-common-x86_64Upgrade perf6.12Upgrade python3-perf6.12Upgrade kernel6.12-modules-extraUpgrade kernel6.12Upgrade kernel-livepatch-6.12.29-33.102Upgrade kernel-libbpfUpgrade kernel6.12-debuginfo-common-aarch64Upgrade kernel-headersUpgrade perf6.12-debuginfoUpgrade bpftool-debuginfoUpgrade kernel-libbpf-develUpgrade kernel-modules-extra-commonUpgrade kernel-tools-develUpgrade kernel-develUpgrade kernel-toolsUpgrade python3-perf6.12-debuginfoUpgrade bpftoolUpgrade kernel6.12-debuginfoUpgrade kernel-libbpf-debuginfoUpgrade kernel-libbpf-static | Jun 3, 2025 | Mar 27, 2025 |
| Debian | — | Upgrade linux | Jul 23, 2026 | Jul 23, 2026 |
| Oracle_linux | — | Upgrade kernel-uek | Oct 16, 2025 | Mar 27, 2025 |
| Redhat_linux | — | No solution exists | Jul 9, 2025 | Mar 27, 2025 |
| Suse | — | Upgrade kernel-obs-buildUpgrade kernel-rt-optionalUpgrade kernel-rt-extraUpgrade kselftests-kmp-rtUpgrade dlm-kmp-rtUpgrade gfs2-kmp-defaultUpgrade dlm-kmp-defaultUpgrade ocfs2-kmp-64kbUpgrade reiserfs-kmp-azureUpgrade kernel-source-vanillaUpgrade dtb-marvellUpgrade dtb-rockchipUpgrade kernel-azure-develUpgrade kernel-default-livepatchUpgrade kernel-kvmsmall-vdsoUpgrade reiserfs-kmp-64kbUpgrade kernel-default-base-rebuildUpgrade dtb-caviumUpgrade kernel-default-baseUpgrade kernel-rt_debugUpgrade kernel-rt_debug-develUpgrade kernel-64kb-extraUpgrade kernel-default-vdsoUpgrade kernel-default-livepatch-develUpgrade dtb-alteraUpgrade dtb-broadcomUpgrade kernel-debug-vdsoUpgrade kernel-rtUpgrade gfs2-kmp-azureUpgrade kernel-source-rtUpgrade dtb-qcomUpgrade reiserfs-kmp-rtUpgrade dtb-sprdUpgrade dtb-nvidiaUpgrade kselftests-kmp-azureUpgrade kernel-docsUpgrade kernel-azure-optionalUpgrade kernel-azureUpgrade cluster-md-kmp-64kbUpgrade dtb-allwinnerUpgrade kernel-rt-vdsoUpgrade ocfs2-kmp-defaultUpgrade kernel-defaultUpgrade kernel-docs-htmlUpgrade cluster-md-kmp-defaultUpgrade kernel-rt-livepatch-develUpgrade kernel-azure-vdsoUpgrade dtb-amazonUpgrade kernel-syms-azureUpgrade kernel-64kb-develUpgrade kernel-debugUpgrade kernel-sourceUpgrade kernel-syms-rtUpgrade dtb-lgUpgrade gfs2-kmp-64kbUpgrade kernel-zfcpdumpUpgrade dtb-hisiliconUpgrade dtb-armUpgrade kernel-symsUpgrade kernel-source-azureUpgrade kernel-rt-develUpgrade kernel-64kb-optionalUpgrade kernel-azure-extraUpgrade dtb-freescaleUpgrade dtb-exynosUpgrade dtb-amdUpgrade ocfs2-kmp-azureUpgrade cluster-md-kmp-azureUpgrade kernel-debug-develUpgrade dtb-renesasUpgrade dtb-mediatekUpgrade dtb-socionextUpgrade kernel-kvmsmall-develUpgrade kernel-default-extraUpgrade dlm-kmp-64kbUpgrade kernel-rt_debug-vdsoUpgrade kselftests-kmp-defaultUpgrade dtb-xilinxUpgrade kernel-kvmsmallUpgrade kernel-devel-rtUpgrade kernel-devel-azureUpgrade kselftests-kmp-64kbUpgrade kernel-macrosUpgrade ocfs2-kmp-rtUpgrade kernel-develUpgrade kernel-default-optionalUpgrade kernel-64kbUpgrade gfs2-kmp-rtUpgrade dtb-appleUpgrade dtb-amlogicUpgrade reiserfs-kmp-defaultUpgrade kernel-default-develUpgrade kernel-obs-qaUpgrade dtb-apmUpgrade dlm-kmp-azureUpgrade cluster-md-kmp-rt | Dec 5, 2025 | May 21, 2025 |
| Ubuntu | — | Upgrade linux-image-virtual-6.8Upgrade linux-image-6.8.0-1046-azureUpgrade linux-image-raspi-realtime-6.8Upgrade linux-image-6.8.0-1043-oracleUpgrade linux-image-raspi-6.8Upgrade linux-image-nvidia-6.8Upgrade linux-image-gcp-64k-6.8Upgrade linux-image-gcp-fips-6.8Upgrade linux-image-6.8.0-1030-gkeopUpgrade linux-image-6.8.0-1044-ibmUpgrade linux-image-raspiUpgrade linux-image-6.8.0-2037-raspi-realtimeUpgrade linux-image-realtimeUpgrade linux-image-lowlatency-hwe-22.04Upgrade linux-image-realtime-6.8.1Upgrade linux-image-nvidia-lowlatency-64k-6.8Upgrade linux-image-gcp-64kUpgrade linux-image-aws-64kUpgrade linux-image-nvidia-64k-hwe-22.04Upgrade linux-image-6.8.0-1043-gkeUpgrade linux-image-6.8.0-100-generic-64kUpgrade linux-image-oem-22.04cUpgrade linux-image-6.8.0-1051-azureUpgrade linux-image-fipsUpgrade linux-image-6.8.0-1046-nvidia-lowlatency-64kUpgrade linux-image-intel-iot-realtimeUpgrade linux-image-oracle-lts-24.04Upgrade linux-image-oem-22.04dUpgrade linux-image-azure-6.8Upgrade linux-image-6.8.0-1046-nvidiaUpgrade linux-image-6.8.0-1047-gcpUpgrade linux-image-oracleUpgrade linux-image-oem-22.04Upgrade linux-image-generic-64kUpgrade linux-image-generic-64k-hwe-22.04Upgrade linux-image-nvidia-lowlatency-64kUpgrade linux-image-lowlatency-64kUpgrade linux-image-nvidia-lowlatency-6.8Upgrade linux-image-6.8.0-100-lowlatencyUpgrade linux-image-intel-iotgUpgrade linux-image-genericUpgrade linux-image-gkeUpgrade linux-image-nvidiaUpgrade linux-image-gkeopUpgrade linux-image-6.8.0-1046-aws-64kUpgrade linux-image-lowlatency-64k-hwe-22.04Upgrade linux-image-nvidia-64k-6.8Upgrade linux-image-xilinx-6.8Upgrade linux-image-lowlatency-6.8Upgrade linux-image-aws-fipsUpgrade linux-image-gcp-64k-lts-24.04Upgrade linux-image-generic-lpaeUpgrade linux-image-lowlatency-64k-6.8Upgrade linux-image-xilinx-zynqmpUpgrade linux-image-nvidia-hwe-22.04Upgrade linux-image-azure-fips-6.8Upgrade linux-image-6.8.0-100-lowlatency-64kUpgrade linux-image-lowlatencyUpgrade linux-image-nvidia-lowlatencyUpgrade linux-image-ibmUpgrade linux-image-6.8.0-1046-nvidia-lowlatencyUpgrade linux-image-generic-hwe-22.04Upgrade linux-image-aws-64k-lts-24.04Upgrade linux-image-6.8.0-1047-raspiUpgrade linux-image-6.8.0-1043-oracle-64kUpgrade linux-image-oem-22.04aUpgrade linux-image-6.8.0-100-genericUpgrade linux-image-6.8.0-1046-aws-fipsUpgrade linux-image-6.8.0-1047-gcp-64kUpgrade linux-image-realtime-hwe-22.04Upgrade linux-image-ibm-lts-24.04Upgrade linux-image-aws-fips-6.8Upgrade linux-image-ibm-classicUpgrade linux-image-awsUpgrade linux-image-gke-64k-6.8Upgrade linux-image-gcpUpgrade linux-image-generic-64k-6.8Upgrade linux-image-aws-64k-6.8Upgrade linux-image-gcp-fipsUpgrade linux-image-ibm-6.8Upgrade linux-image-6.8.0-1046-nvidia-64kUpgrade linux-image-gke-6.8Upgrade linux-image-fips-6.8Upgrade linux-image-6.8.0-1023-xilinxUpgrade linux-image-gke-64kUpgrade linux-image-virtualUpgrade linux-image-kvmUpgrade linux-image-6.8.0-1046-azure-fipsUpgrade linux-image-6.8.0-100-fipsUpgrade linux-image-virtual-hwe-22.04Upgrade linux-image-6.8.1-1041-realtimeUpgrade linux-image-azureUpgrade linux-image-gcp-lts-24.04Upgrade linux-image-aws-6.8Upgrade linux-image-nvidia-64kUpgrade linux-image-oracle-64k-6.8Upgrade linux-image-oracle-6.8Upgrade linux-image-6.8.0-1047-gcp-fipsUpgrade linux-image-6.8.0-1046-awsUpgrade linux-image-raspi-realtimeUpgrade linux-image-azure-lts-24.04Upgrade linux-image-6.8.0-1043-gke-64kUpgrade linux-image-gcp-6.8Upgrade linux-image-oem-22.04bUpgrade linux-image-azure-fipsUpgrade linux-image-oracle-64kUpgrade linux-image-aws-lts-24.04Upgrade linux-image-oracle-64k-lts-24.04Upgrade linux-image-generic-6.8Upgrade linux-image-gkeop-6.8Upgrade linux-image-xilinx | Jun 26, 2025 | Mar 27, 2025 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Jul 17, 2026 | Mar 27, 2025 |
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