CVE-2026-89506

Summary

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 Software

VendorProductVersion RangeStatus
LinuxLinux5b2e45049dc06a876bc6b138218ddeb0814502ef < 71d5c41ac583df09a7c32199bef7d42de7267d07affected
LinuxLinux5b2e45049dc06a876bc6b138218ddeb0814502ef < 9e71d0f4944ba5641e01db29b3256c963656d671affected
LinuxLinux5b2e45049dc06a876bc6b138218ddeb0814502ef < 011199f46f44a9fd93a9e5ab5d7fd1328d80e9bfaffected
LinuxLinux6.17affected
LinuxLinux0 < 6.17unaffected
LinuxLinux6.18.50 <= 6.18.*unaffected
LinuxLinux7.2.4 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References