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Vulnerability · Published Mar 27, 2025 · Assigned by Linux

CVE-2025-21884net: better track kernel sockets lifetime

High 7.8

In plain English

A high-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.8High
Exploit odds (30 days)0.2%top 87.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

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

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:13linux6.12.43-1DEBIAN-CVE-2025-21884
Debian:14linux6.16.3-1DEBIAN-CVE-2025-21884
Ubuntu:24.04:LTSlinux6.8.0-100.100UBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux6.8.0-100.100USN-8028-1
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-aws6.8.0-1046.49UBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-aws6.8.0-1046.49USN-8028-5
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1046.49~22.04.1USN-8028-5
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1046.49~22.04.1UBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-azure6.8.0-1046.52USN-8074-1
Ubuntu:24.04:LTSlinux-azure6.8.0-1046.52UBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1051.57~22.04.1USN-8126-1
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1051.57~22.04.1UBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1046.53UBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1046.53~22.04.1UBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-gcp6.8.0-1047.50USN-8031-3
Ubuntu:24.04:LTSlinux-gcp6.8.0-1047.50UBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1047.50~22.04.2UBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1047.50~22.04.2USN-8031-1
Ubuntu:24.04:LTSlinux-gke6.8.0-1043.48USN-8031-3
Ubuntu:24.04:LTSlinux-gke6.8.0-1043.48UBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1030.33UBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1030.33USN-8028-5
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-100.100~22.04.1UBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-100.100~22.04.1USN-8028-6
Ubuntu:24.04:LTSlinux-ibm6.8.0-1044.44USN-8028-8
Ubuntu:24.04:LTSlinux-ibm6.8.0-1044.44UBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1044.44~22.04.1USN-8028-8
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1044.44~22.04.1UBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-intelno fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-100.100.1USN-8052-1
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-100.100.1UBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-100.100.1~22.04.1UBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-100.100.1~22.04.1USN-8028-6
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1046.49UBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1046.49USN-8028-5
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1046.49~22.04.1USN-8028-5
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1046.49~22.04.1UBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1046.49.1USN-8028-7
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1046.49.1UBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1020.20UBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-oracle6.8.0-1043.44USN-8028-5
Ubuntu:24.04:LTSlinux-oracle6.8.0-1043.44UBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1043.44~22.04.1UBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1043.44~22.04.1USN-8028-5
Ubuntu:24.04:LTSlinux-raspi6.8.0-1047.51UBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-raspi6.8.0-1047.51USN-8028-1
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-100.100~22.04.1UBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2025-21884
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1023.24UBUNTU-CVE-2025-21884
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1023.24USN-8052-2

Affected products (as reported)

VendorProductVersions
Linux Linux 0cafd77dcd032d1687efaba5598cf07bce85997f – before 2668e038800b946d269f96ec1b258c01930a242c0cafd77dcd032d1687efaba5598cf07bce85997f – before 4ceb0bd4ffd009821b585ce6a8033b12b59fb5fb0cafd77dcd032d1687efaba5598cf07bce85997f – before c31a732fac46b00b95b78fcc9c37cb48dd6f2e0c0cafd77dcd032d1687efaba5598cf07bce85997f – before 5c70eb5c593d64d93b178905da215a9fd288a4b5
Linux Linux 6.2

References