CVE-2024-56756: nvme-pci: fix freeing of the HMB descriptor table

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-12-29 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: nvme-pci: fix freeing of the HMB descriptor table The HMB descriptor table is sized to the maximum number of descriptors that could be used for a given device, but __nvme_alloc_host_mem could break out of the loop earlier on memory allocation failure and end up using less descriptors than planned for, which leads to an incorrect size passed to dma_free_coherent. In practice this was not showing up because the number of descriptors tends to be low and the dma coherent allocator always allocates and frees at least a page.

Affected products

Linux kernel: from 4.13 before 5.4.287; from 5.5 before 5.10.231; from 5.11 before 5.15.174; from 5.16 before 6.1.120; from 6.2 before 6.6.64; from 6.7 before 6.11.11 — fixed in 5.10.231, 5.15.174, 5.4.287, 6.1.120, 6.11.11, 6.12.2

How to fix

Upgrade to a fixed version: Linux kernel 5.10.231, 5.15.174, 5.4.287, 6.1.120. Check the vendor advisory for mitigations.

References

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