Log in Start free

Vulnerability · Published Mar 12, 2025 · Assigned by Linux

CVE-2025-21857net/sched: cls_api: fix error handling causing NULL dereference

Medium 5.5

In plain English

A medium-severity null pointer dereference 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)5.5Medium
Exploit odds (30 days)0.2%top 87.9% 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/sched: cls_api: fix error handling causing NULL dereference tcf_exts_miss_cookie_base_alloc() calls xa_alloc_cyclic() which can return 1 if the allocation succeeded after wrapping. This was treated as an error, with value 1 returned to caller tcf_exts_init_ex() which sets exts->actions to NULL and returns 1 to caller fl_change(). fl_change() treats err == 1 as success, calling tcf_exts_validate_ex() which calls tcf_action_init() with exts->actions as argument, where it is dereferenced. Example trace: BUG: kernel NULL pointer dereference, address: 0000000000000000 CPU: 114 PID: 16151 Comm: handler114 Kdump: loaded Not tainted 5.14.0-503.16.1.el9_5.x86_64 #1 RIP: 0010:tcf_action_init+0x1f8/0x2c0 Call Trace: tcf_action_init+0x1f8/0x2c0 tcf_exts_validate_ex+0x175/0x190 fl_change+0x537/0x1120 [cls_flower]

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:13linux6.12.17-1DEBIAN-CVE-2025-21857
Debian:14linux6.12.17-1DEBIAN-CVE-2025-21857
Ubuntu:24.04:LTSlinux6.8.0-78.78UBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-aws6.8.0-1035.37UBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1035.37~22.04.1UBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-azure6.8.0-1034.39UBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-azure-6.116.11.0-1015.15~24.04.1UBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1034.39~22.04.1UBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-azure-nvidia6.8.0-1022.23UBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-gcp6.8.0-1036.38UBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-gcp-6.116.11.0-1015.15~24.04.1UBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1036.38~22.04.1UBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-gke6.8.0-1032.36UBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1019.21UBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-hwe-6.116.11.0-26.26~24.04.1UBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-78.78~22.04.1UBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-ibm6.8.0-1033.33UBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1033.33~22.04.1UBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-intelno fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-78.78.1UBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.116.11.0-1014.15~24.04.1UBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-78.78.1~22.04.1UBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1035.38UBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-nvidia-6.116.11.0-1010.10UBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1035.38~22.04.1UBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1035.38.1UBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1009.9UBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-oem-6.116.11.0-1022.22UBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-oracle6.8.0-1032.33UBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1032.33~22.04.1UBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-raspi6.8.0-1035.39UBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-78.78~22.04.1UBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2025-21857
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2025-21857
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1017.18UBUNTU-CVE-2025-21857

Affected products (as reported)

VendorProductVersions
Linux Linux 80cd22c35c9001fe72bf614d29439de41933deca – before de4b679aa3b4da7ec34f639df068b914f20e3c3c80cd22c35c9001fe72bf614d29439de41933deca – before 3e4c56cf41876ef2a82f0877fe2a67648f8632b880cd22c35c9001fe72bf614d29439de41933deca – before 3c74b5787caf59bb1e9c5fe0a360643a71eb1e8a80cd22c35c9001fe72bf614d29439de41933deca – before 071ed42cff4fcdd89025d966d48eabef59913bf2
Linux Linux 6.3

Weakness: CWE-476 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References