CVE-2025-21676

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux95698ff6177b5f1f13f251da60e7348413046ae4 < eacdcc14f3c8d4c1447565521e792ddb3a67e08daffected
LinuxLinux95698ff6177b5f1f13f251da60e7348413046ae4 < 8a0097db0544b658c159ac787319737712063a23affected
LinuxLinux95698ff6177b5f1f13f251da60e7348413046ae4 < 1425cb829556398f594658512d49292f988a2ab0affected
LinuxLinux95698ff6177b5f1f13f251da60e7348413046ae4 < 001ba0902046cb6c352494df610718c0763e77a5affected
LinuxLinux6.1affected
LinuxLinux0 < 6.1unaffected
LinuxLinux6.1.167 <= 6.1.*unaffected
LinuxLinux6.6.74 <= 6.6.*unaffected
LinuxLinux6.12.11 <= 6.12.*unaffected
LinuxLinux6.13 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References