CVE-2026-31644

HIGHCVSS 7.8/10EPSS 0.13%

Last modified

CVE-2026-31644 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: net: lan966x: fix use-after-free and leak in lan966x_fdma_reload() When lan966x_fdma_reload() fails to allocate new RX buffers, the restore path restarts DMA using old descriptors whose pages were already freed via lan966x_fdma_rx_free_pages(). Since page_pool_put_full_page() can release pages back to the buddy allocator, the hardware may DMA into memory now owned by other kernel subsystems. Additionally, on the restore path, the newly created page pool (if allocation partially succeeded) is overwritten without being destroyed, leaking it. Fix both issues by deferring the release of old pages until after the new allocation succeeds. EPSS estimates a 0.13% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: net: lan966x: fix use-after-free and leak in lan966x_fdma_reload() When lan966x_fdma_reload() fails to allocate new RX buffers, the restore path restarts DMA using old descriptors whose pages were already freed via lan966x_fdma_rx_free_pages(). Since page_pool_put_full_page() can release pages back to the buddy allocator, the hardware may DMA into memory now owned by other kernel subsystems. Additionally, on the restore path, the newly created page pool (if allocation partially succeeded) is overwritten without being destroyed, leaking it. Fix both issues by deferring the release of old pages until after the new allocation succeeds. Save the old page array before the allocation so old pages can be freed on the success path. On the failure path, the old descriptors, pages and page pool are all still valid, making the restore safe. Also ensure the restore path re-enables NAPI and wakes the netdev, matching the success path.

Metrics

CVSS 3.1
7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
0.13%

2.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 6.12.1, < 6.12.82
LinuxLinux Kernel>= 6.13, < 6.18.23
LinuxLinux Kernel>= 6.19, < 6.19.13
LinuxLinux Kernel6.12
LinuxLinux Kernel7.0Rc1

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-31644?
In the Linux kernel, the following vulnerability has been resolved: net: lan966x: fix use-after-free and leak in lan966x_fdma_reload() When lan966x_fdma_reload() fails to allocate new RX buffers, the restore path restarts DMA using old descriptors whose pages were already freed via lan966x_fdma_rx_free_pages(). Since page_pool_put_full_page() can release pages back to the buddy allocator, the hardware may DMA into memory now owned by other kernel subsystems. Additionally, on the restore path, the newly created page pool (if allocation partially succeeded) is overwritten without being destroyed, leaking it. Fix both issues by deferring the release of old pages until after the new allocation succeeds. Save the old page array before the allocation so old pages can be freed on the success path. On the failure path, the old descriptors, pages and page pool are all still valid, making the restore safe. Also ensure the restore path re-enables NAPI and wakes the netdev, matching the success path.
How severe is CVE-2026-31644?
CVE-2026-31644 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.13% probability of exploitation in the next 30 days.
How do I fix CVE-2026-31644?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-31644?

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Source: NVD / NIST