CVE-2025-21980 sched: address a potential NULL pointer dereference in the GRED scheduler.

What is CVE-2025-21980?

CVE-2025-21980 is a medium-severity vulnerability in Linux kernel, published on 1 Apr 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

sched: address a potential NULL pointer dereference in the GRED scheduler.

If kzalloc in gred_init returns a NULL pointer, the code follows the error handling path, invoking gred_destroy. This, in turn, calls gred_offload, where memset could receive a NULL pointer as input, potentially leading to a kernel crash.

When table->opt is NULL in gred_init(), gred_change_table_def() is not called yet, so it is not necessary to call ->ndo_setup_tc() in gred_offload().

Weakness: CWE-476

Which versions are affected by CVE-2025-21980?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2025-21980?

Apply the vendor's patch.

Is CVE-2025-21980 being exploited?

There is no known exploitation of CVE-2025-21980 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-59901, BELL-CVE-2025-21980, DEBIAN-CVE-2025-21980, GHSA-mwfv-f593-4f6x, ROOT-OS-UBUNTU-2404-CVE-2025-21980, UBUNTU-CVE-2025-21980.