What’s Vulnerable › Vulnerabilities

CVE-2026-89506: RDMA/uverbs: Add UVERBS_ATTR_UHW to UVERBS_METHOD_REG_MR

• Severity: unknown
• 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: 2026-09-11 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/uverbs: Add UVERBS_ATTR_UHW to UVERBS_METHOD_REG_MR The original commit missed that three drivers (mthca, irdma, siw) have UHW data associated with reg_mr that cannot be passed through the ioctl. They also assume that the udata cannot be NULL, so failing to pass a valid udata can trigger a NULL udata crash in those drivers. This never happens in real systems since in rdma-core ibv_cmd_reg_mr_ex() does not accept a udata and those three drivers don't use it, however a malicious userspace could trigger it.

Affected products

• Linux kernel: 6.17 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux kernel 7.3. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/011199f46f44a9fd93a9e5ab5d7fd1328d80e9bf
• https://git.kernel.org/stable/c/71d5c41ac583df09a7c32199bef7d42de7267d07
• https://git.kernel.org/stable/c/9e71d0f4944ba5641e01db29b3256c963656d671

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