CVE-2026-31590

Summary

In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Drop WARN on large size for KVM_MEMORY_ENCRYPT_REG_REGION Drop the WARN in sev_pin_memory() on npages overflowing an int, as the WARN is comically trivially to trigger from userspace, e.g. by doing: struct kvm_enc_region range = { .addr = 0, .size = -1ul, }; __vm_ioctl(vm, KVM_MEMORY_ENCRYPT_REG_REGION, &range); Note, the checks in sev_mem_enc_register_region() that presumably exist to verify the incoming address+size are completely worthless, as both "addr" and "size" are u64s and SEV is 64-bit only, i.e. they _can't_ be greater than ULONG_MAX. That wart will be cleaned up in the near future. if (range->addr > ULONG_MAX || range->size > ULONG_MAX) return -EINVAL; Opportunistically add a comment to explain why the code calculates the number of pages the "hard" way, e.g. instead of just shifting @ulen.

Impact & exploitability

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

Affected products we track (1)

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

Official patch: https://git.kernel.org/stable/c/1cba4dcd795daf6d257122779fb6a349edf03914 ↗

Additional information

• NVD record
• https://git.kernel.org/stable/c/1cba4dcd795daf6d257122779fb6a349edf03914Patch
• https://git.kernel.org/stable/c/28cc13ca20431b127d42d84ba10898d03e2c8267Patch
• https://git.kernel.org/stable/c/8acffeef5ef720c35e513e322ab08e32683f32f2Patch
• https://git.kernel.org/stable/c/ab423e5892826202a660b5ac85d1125b0e8301a5Patch
• https://git.kernel.org/stable/c/b670833749ffd8681361db2bb047c6f2e3075f3aPatch
• https://git.kernel.org/stable/c/6a8e3c82122737529b25ef2a048fbcc569d8c055
• https://git.kernel.org/stable/c/a703933bcfa5cc76ca10e2048464600e74136099
• https://git.kernel.org/stable/c/abcd43ff579abd0a654bb4636086e78819dd5f4c