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.
Metrics
Affected Vendors & Products
References
History
Fri, 24 Apr 2026 15:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | KVM: SEV: Drop WARN on large size for KVM_MEMORY_ENCRYPT_REG_REGION | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-04-24T14:42:17.629Z
Reserved: 2026-03-09T15:48:24.120Z
Link: CVE-2026-31590
No data.
Status : Awaiting Analysis
Published: 2026-04-24T15:16:36.170
Modified: 2026-04-24T17:51:40.810
Link: CVE-2026-31590
No data.
OpenCVE Enrichment
No data.