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.

Classification

CVE ID: CVE-2025-21676

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 5.01% (scored less or equal to compared to others)

EPSS Date: 2025-03-01 (when was this score calculated)

References

https://git.kernel.org/stable/c/8a0097db0544b658c159ac787319737712063a23
https://git.kernel.org/stable/c/1425cb829556398f594658512d49292f988a2ab0
https://git.kernel.org/stable/c/001ba0902046cb6c352494df610718c0763e77a5

Timeline