CVE-2025-21676: linux NULL Pointer Dereference
Vulnerability summary
CVE-2025-21676 is a high (CVSS 7.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.45% chance of exploitation in the next 30 days, higher than 37.6% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 18 · Related 18Timeline
- 31-01-2025PublishedVulnerability first disclosed.
- 15-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: net: fec: handle page_pool_dev_alloc_pages error The fec_enet_update_cbd function calls page_pool_dev_alloc_pages but did not handle the case when it returned NULL. There was a WARN_ON(!new_page) but it would still proceed to use the NULL pointer and then crash. This case does seem somewhat rare but when the system is under memory pressure it can happen. One case where I can duplicate this with some frequency is when writing over a smbd share to a SATA HDD attached to an imx6q. Setting /proc/sys/vm/min_free_kbytes to higher values also seems to solve the problem for my test case. But it still seems wrong that the fec driver ignores the memory allocation error and can crash. This commit handles the allocation error by dropping the current packet.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
- NVDNIST5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
EPSS trend
Probability
0.45%
Chance of exploitation in the next 30 days
Percentile
38%
Versus all other CVEs
30-day change
+0.01 pp
From 0.44% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu106 products
- linux< 6.8.0-62.65
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 6.8.0-1030.32
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 95698ff6177b5f1f13f251da60e7348413046ae4, < eacdcc14f3c8d4c1447565521e792ddb3a67e08d | ≥ 95698ff6177b5f1f13f251da60e7348413046ae4, < 8a0097db0544b658c159ac787319737712063a23 | ≥ 95698ff6177b5f1f13f251da60e7348413046ae4, < 1425cb829556398f594658512d49292f988a2ab0 | ≥ 95698ff6177b5f1f13f251da60e7348413046ae4, < 001ba0902046cb6c352494df610718c0763e77a5 | 6.1
- linux_kernel≥ 6.1, < 6.6.74 | ≥ 6.7, < 6.12.11 | 6.13:rc1 | 6.13:rc2 | 6.13:rc3 | 6.13:rc4 | 6.13:rc5 | 6.13:rc6 | 6.13:rc7
Debian1 product
- linux< 6.1.170-1 | < 6.12.11-1
3 vendors · 109 products