CVE-2026-89506
Summary
by MITRE • 09/11/2026
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.
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