In the Linux kernel, the following vulnerability has been resolved:
KVM: SEV: Allocate full pages for {DE,EN}CRYPT ops on SNP-enabled hosts
When {de,en}crypting memory of an SEV or SEV-ES guest on an SNP-enabled
host via a temporary buffer, allocate a full 4KiB page for the buffer to
ensure the page containing the buffer is wholly owned by KVM, i.e. won't
be concurrently allocated and accessed by other kernel code while KVM is
using the buffer to {de,en}crypt memory. On SNP-enabled platforms, when
sending SEV/SEV-ES commands that trigger firmware writes to memory, the
to-be-written page(s) must be (temporarily) assigned to Firmware (as
required by the SNP architecture, to guard against using such commands as
gadgets to attack SNP guests). See snp_map_cmd_buf_desc() and friends.
Unfortunately, transferring ownership of a page to Firmware makes the page
inaccessible to software, and thus writes generate RMP #PF violations. If
KVM uses a sub-page allocation for its temporary buffer, some other actor
in the kernel can allocate and use the other portions of the page, and thus
trigger unexpected (and seemingly spurious) RMP #PF violations due to
software attempting to access a Firmware-owned page.
BUG: unable to handle page fault for address: ffff906ae30f0300
#PF: supervisor write access in kernel mode
#PF: error_code(0x80000003) - RMP violation
PGD 6b1b80d067 P4D 6b1b80d067 PUD 100231e2063 PMD 10055a88063 PTE 80000100630f0163
SEV-SNP: PFN 0x100630f0 unassigned, dumping non-zero entries in 2M PFN region: [0x10063000 - 0x10063200]
Oops: Oops: 0003 [#1] SMP
CPU: 70 UID: 0 PID: 10658 Comm: svw_WaiterThrea Tainted: G U W O 7.1.0-smp--c22293789940-seanjc-next #1 PREEMPTLAZY
Tainted: [U]=USER, [W]=WARN, [O]=OOT_MODULE
Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 34.86.0-102 01/25/2026
RIP: 0010:memset+0xf/0x20
Call Trace:
<TASK>
__kvmalloc_node_noprof+0x2a4/0x710
do_getxattr+0x4e/0x130
path_getxattrat+0x125/0x1b0
do_syscall_64+0x10a/0x480
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f3a22cb6daa
</TASK>
Modules linked in: kvm_amd kvm irqbypass vfat fat ccp k10temp sha3 libsha3 i2c_piix4 gq(O) cdc_acm xhci_pci xhci_hcd
gsmi: Log Shutdown Reason 0x03
CR2: ffff906ae30f0300
---[ end trace 0000000000000000 ]---
RIP: 0010:memset+0xf/0x20
Kernel panic - not syncing: Fatal exception
Kernel Offset: 0x39e00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
gsmi: Log Shutdown Reason 0x02
KVM: SEV: Allocate full pages for {DE,EN}CRYPT ops on SNP-enabled hosts
When {de,en}crypting memory of an SEV or SEV-ES guest on an SNP-enabled
host via a temporary buffer, allocate a full 4KiB page for the buffer to
ensure the page containing the buffer is wholly owned by KVM, i.e. won't
be concurrently allocated and accessed by other kernel code while KVM is
using the buffer to {de,en}crypt memory. On SNP-enabled platforms, when
sending SEV/SEV-ES commands that trigger firmware writes to memory, the
to-be-written page(s) must be (temporarily) assigned to Firmware (as
required by the SNP architecture, to guard against using such commands as
gadgets to attack SNP guests). See snp_map_cmd_buf_desc() and friends.
Unfortunately, transferring ownership of a page to Firmware makes the page
inaccessible to software, and thus writes generate RMP #PF violations. If
KVM uses a sub-page allocation for its temporary buffer, some other actor
in the kernel can allocate and use the other portions of the page, and thus
trigger unexpected (and seemingly spurious) RMP #PF violations due to
software attempting to access a Firmware-owned page.
BUG: unable to handle page fault for address: ffff906ae30f0300
#PF: supervisor write access in kernel mode
#PF: error_code(0x80000003) - RMP violation
PGD 6b1b80d067 P4D 6b1b80d067 PUD 100231e2063 PMD 10055a88063 PTE 80000100630f0163
SEV-SNP: PFN 0x100630f0 unassigned, dumping non-zero entries in 2M PFN region: [0x10063000 - 0x10063200]
Oops: Oops: 0003 [#1] SMP
CPU: 70 UID: 0 PID: 10658 Comm: svw_WaiterThrea Tainted: G U W O 7.1.0-smp--c22293789940-seanjc-next #1 PREEMPTLAZY
Tainted: [U]=USER, [W]=WARN, [O]=OOT_MODULE
Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 34.86.0-102 01/25/2026
RIP: 0010:memset+0xf/0x20
Call Trace:
<TASK>
__kvmalloc_node_noprof+0x2a4/0x710
do_getxattr+0x4e/0x130
path_getxattrat+0x125/0x1b0
do_syscall_64+0x10a/0x480
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f3a22cb6daa
</TASK>
Modules linked in: kvm_amd kvm irqbypass vfat fat ccp k10temp sha3 libsha3 i2c_piix4 gq(O) cdc_acm xhci_pci xhci_hcd
gsmi: Log Shutdown Reason 0x03
CR2: ffff906ae30f0300
---[ end trace 0000000000000000 ]---
RIP: 0010:memset+0xf/0x20
Kernel panic - not syncing: Fatal exception
Kernel Offset: 0x39e00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
gsmi: Log Shutdown Reason 0x02
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 04 Sep 2026 21:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-362 |
Fri, 04 Sep 2026 16:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Allocate full pages for {DE,EN}CRYPT ops on SNP-enabled hosts When {de,en}crypting memory of an SEV or SEV-ES guest on an SNP-enabled host via a temporary buffer, allocate a full 4KiB page for the buffer to ensure the page containing the buffer is wholly owned by KVM, i.e. won't be concurrently allocated and accessed by other kernel code while KVM is using the buffer to {de,en}crypt memory. On SNP-enabled platforms, when sending SEV/SEV-ES commands that trigger firmware writes to memory, the to-be-written page(s) must be (temporarily) assigned to Firmware (as required by the SNP architecture, to guard against using such commands as gadgets to attack SNP guests). See snp_map_cmd_buf_desc() and friends. Unfortunately, transferring ownership of a page to Firmware makes the page inaccessible to software, and thus writes generate RMP #PF violations. If KVM uses a sub-page allocation for its temporary buffer, some other actor in the kernel can allocate and use the other portions of the page, and thus trigger unexpected (and seemingly spurious) RMP #PF violations due to software attempting to access a Firmware-owned page. BUG: unable to handle page fault for address: ffff906ae30f0300 #PF: supervisor write access in kernel mode #PF: error_code(0x80000003) - RMP violation PGD 6b1b80d067 P4D 6b1b80d067 PUD 100231e2063 PMD 10055a88063 PTE 80000100630f0163 SEV-SNP: PFN 0x100630f0 unassigned, dumping non-zero entries in 2M PFN region: [0x10063000 - 0x10063200] Oops: Oops: 0003 [#1] SMP CPU: 70 UID: 0 PID: 10658 Comm: svw_WaiterThrea Tainted: G U W O 7.1.0-smp--c22293789940-seanjc-next #1 PREEMPTLAZY Tainted: [U]=USER, [W]=WARN, [O]=OOT_MODULE Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 34.86.0-102 01/25/2026 RIP: 0010:memset+0xf/0x20 Call Trace: <TASK> __kvmalloc_node_noprof+0x2a4/0x710 do_getxattr+0x4e/0x130 path_getxattrat+0x125/0x1b0 do_syscall_64+0x10a/0x480 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7f3a22cb6daa </TASK> Modules linked in: kvm_amd kvm irqbypass vfat fat ccp k10temp sha3 libsha3 i2c_piix4 gq(O) cdc_acm xhci_pci xhci_hcd gsmi: Log Shutdown Reason 0x03 CR2: ffff906ae30f0300 ---[ end trace 0000000000000000 ]--- RIP: 0010:memset+0xf/0x20 Kernel panic - not syncing: Fatal exception Kernel Offset: 0x39e00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) gsmi: Log Shutdown Reason 0x02 | |
| Title | KVM: SEV: Allocate full pages for {DE,EN}CRYPT ops on SNP-enabled hosts | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-04T15:55:05.021Z
Reserved: 2026-08-26T14:34:25.797Z
Link: CVE-2026-80853
No data.
Status : Received
Published: 2026-09-04T16:18:14.233
Modified: 2026-09-04T16:18:14.233
Link: CVE-2026-80853
No data.
OpenCVE Enrichment
Updated: 2026-09-04T21:00:13Z
Weaknesses