Upstream information

CVE-2026-63794 at MITRE

Description

In the Linux kernel, the following vulnerability has been resolved:

KVM: SVM: Fix page overflow in sev_dbg_crypt() for ENCRYPT path

In sev_dbg_crypt(), the per-iteration transfer length is bounded by
the source page offset (PAGE_SIZE - s_off) but not by the destination
page offset (PAGE_SIZE - d_off). When d_off > s_off, the encrypt
path (__sev_dbg_encrypt_user) performs a read-modify-write using a
single-page intermediate buffer (dst_tpage):

1. __sev_dbg_decrypt() expands the size to round_up(len + (d_off & 15), 16)
before issuing the PSP command. If len + (d_off & 15) > PAGE_SIZE,
the PSP writes beyond the end of the 4096-byte dst_tpage allocation.

2. The subsequent memcpy()/copy_from_user() into
page_address(dst_tpage) + (d_off & 15) of 'len' bytes overflows
by up to 15 bytes under the same condition.

Trigger example: s_off = 0, d_off = 1, debug.len = PAGE_SIZE -
the PSP is instructed to write round_up(4097, 16) = 4112 bytes to
a 4096-byte buffer.

Fix by also bounding len by (PAGE_SIZE - d_off), the same check that
sev_send_update_data() already performs for its single-page guest
region.

==================================================================
BUG: KASAN: slab-use-after-free in sev_dbg_crypt+0x993/0xd10 [kvm_amd]
Write of size 4095 at addr ff110062293bb009 by task sev_dbg_test/228214

CPU: 96 UID: 0 PID: 228214 Comm: sev_dbg_test Tainted: G U W 7.0.0-smp--5ce9b0c48211-dbg #156 PREEMPTLAZY
Tainted: [U]=USER, [W]=WARN
Hardware name: Google Astoria/astoria, BIOS 0.20250817.1-0 08/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0x54/0x70
print_report+0xbc/0x260
kasan_report+0xa2/0xd0
kasan_check_range+0x25f/0x2c0
__asan_memcpy+0x40/0x70
sev_dbg_crypt+0x993/0xd10 [kvm_amd]
sev_mem_enc_ioctl+0x33c/0x450 [kvm_amd]
kvm_vm_ioctl+0x65d/0x6d0 [kvm]
__se_sys_ioctl+0xb2/0x100
do_syscall_64+0xe8/0x870
entry_SYSCALL_64_after_hwframe+0x4b/0x53
</TASK>

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x7fe72b6a0 pfn:0x62293bb
memcg:ff11000112827d82
flags: 0x1400000000000000(node=1|zone=1)
raw: 1400000000000000 0000000000000000 dead000000000122 0000000000000000
raw: 00000007fe72b6a0 0000000000000000 00000001ffffffff ff11000112827d82
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ff110062293bbf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ff110062293bbf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ff110062293bc000: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
^
ff110062293bc080: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ff110062293bc100: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================
Disabling lock debugging due to kernel taint

[sean: add sample KASAN splat, Fixes, and stable@]

SUSE information

Overall state of this security issue: Pending

This issue is currently rated as having important severity.

CVSS v3 Scores
CVSS detail SUSE
Base Score 7
Vector CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector Local
Attack Complexity High
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality Impact High
Integrity Impact High
Availability Impact High
CVSSv3 Version 3.1
CVSS v4 Scores
CVSS detail SUSE
Base Score 7.5
Vector CVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Attack Vector Local
Attack Complexity High
Attack Requirements None
Privileges Required None
User Interaction None
Vulnerable System Confidentiality Impact High
Vulnerable System Integrity Impact High
Vulnerable System Availability Impact High
Subsequent System Confidentiality Impact None
Subsequent System Integrity Impact None
Subsequent System Availability Impact None
CVSSv4 Version 4.0

Note from the SUSE Security Team on the kernel-default package

SUSE will no longer fix all CVEs in the Linux Kernel anymore, but declare some bug classes as won't fix. Please refer to TID 21496 for more details.

SUSE Bugzilla entry: 1271964 [NEW]

No SUSE Security Announcements cross referenced.


Status of this issue by product and package

Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.

Product(s) Source package State
Products under general support and receiving all security fixes.
SUSE Linux Enterprise Desktop 15 SP7 kernel-default Already fixed
SUSE Linux Enterprise Desktop 15 SP7 kernel-source Already fixed
SUSE Linux Enterprise High Availability Extension 15 SP7 kernel-default Already fixed
SUSE Linux Enterprise High Availability Extension 15 SP7 kernel-source Already fixed
SUSE Linux Enterprise High Availability Extension 16.0 kernel-default Affected
SUSE Linux Enterprise High Availability Extension 16.0 kernel-source Affected
SUSE Linux Enterprise High Availability Extension 16.1 kernel-default Affected
SUSE Linux Enterprise High Availability Extension 16.1 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP7 kernel-default Already fixed
SUSE Linux Enterprise High Performance Computing 15 SP7 kernel-source Already fixed
SUSE Linux Enterprise Live Patching 15 SP7 kernel-default Already fixed
SUSE Linux Enterprise Live Patching 15 SP7 kernel-source Already fixed
SUSE Linux Enterprise Micro 5.3 kernel-default Affected
SUSE Linux Enterprise Micro 5.3 kernel-rt Affected
SUSE Linux Enterprise Micro 5.3 kernel-source Affected
SUSE Linux Enterprise Micro 5.3 kernel-source-rt Affected
SUSE Linux Enterprise Micro 5.4 kernel-default Affected
SUSE Linux Enterprise Micro 5.4 kernel-rt Affected
SUSE Linux Enterprise Micro 5.4 kernel-source Affected
SUSE Linux Enterprise Micro 5.4 kernel-source-rt Affected
SUSE Linux Enterprise Micro 5.5 kernel-default Affected
SUSE Linux Enterprise Micro 5.5 kernel-source Affected
SUSE Linux Enterprise Micro 5.5 kernel-source-rt Affected
SUSE Linux Enterprise Module for Basesystem 15 SP7 kernel-default Already fixed
SUSE Linux Enterprise Module for Basesystem 15 SP7 kernel-source Already fixed
SUSE Linux Enterprise Module for Development Tools 15 SP7 kernel-default Already fixed
SUSE Linux Enterprise Module for Development Tools 15 SP7 kernel-source Already fixed
SUSE Linux Enterprise Module for Legacy 15 SP7 kernel-default Already fixed
SUSE Linux Enterprise Module for Legacy 15 SP7 kernel-source Already fixed
SUSE Linux Enterprise Module for Public Cloud 15 SP7 kernel-default Already fixed
SUSE Linux Enterprise Module for Public Cloud 15 SP7 kernel-source Already fixed
SUSE Linux Enterprise Real Time 15 SP7 kernel-source-rt Already fixed
SUSE Linux Enterprise Server 15 SP7 kernel-default Already fixed
SUSE Linux Enterprise Server 15 SP7 kernel-source Already fixed
SUSE Linux Enterprise Server 16.0 kernel-source Affected
SUSE Linux Enterprise Server 16.1 kernel-default Affected
SUSE Linux Enterprise Server 16.1 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP7 kernel-default Already fixed
SUSE Linux Enterprise Server for SAP Applications 15 SP7 kernel-source Already fixed
SUSE Linux Enterprise Server for SAP applications 16.0 kernel-source Affected
SUSE Linux Enterprise Server for SAP applications 16.1 kernel-default Affected
SUSE Linux Enterprise Server for SAP applications 16.1 kernel-source Affected
SUSE Linux Enterprise Workstation Extension 15 SP7 kernel-default Already fixed
SUSE Linux Enterprise Workstation Extension 15 SP7 kernel-source Already fixed
SUSE Linux Micro 6.0 kernel-default Already fixed
SUSE Linux Micro 6.0 kernel-source Already fixed
SUSE Linux Micro 6.0 kernel-source-rt Already fixed
SUSE Linux Micro 6.1 kernel-default Already fixed
SUSE Linux Micro 6.1 kernel-source Already fixed
SUSE Linux Micro 6.1 kernel-source-rt Already fixed
SUSE Linux Micro 6.2 kernel-default Affected
SUSE Linux Micro 6.2 kernel-source Affected
SUSE Linux Micro Extras 6.0 kernel-default Already fixed
SUSE Linux Micro Extras 6.0 kernel-source Already fixed
SUSE Linux Micro Extras 6.0 kernel-source-rt Already fixed
SUSE Real Time Module 15 SP7 kernel-source-rt Already fixed
openSUSE Leap 16.0 kernel-source Affected
Products under Long Term Service Pack support and receiving important and critical security fixes.
SUSE Linux Enterprise High Performance Computing 15 SP4 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-default Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP5 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-default Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-source Affected
SUSE Linux Enterprise Live Patching 12 SP5 kernel-default Affected
SUSE Linux Enterprise Live Patching 12 SP5 kernel-source Affected
SUSE Linux Enterprise Live Patching 15 SP4 kernel-default Affected
SUSE Linux Enterprise Live Patching 15 SP4 kernel-source Affected
SUSE Linux Enterprise Live Patching 15 SP5 kernel-default Affected
SUSE Linux Enterprise Live Patching 15 SP5 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP4 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP5 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP6 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP4 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP5 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP6 kernel-source Affected
SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-default Not affected
SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-source Not affected
SUSE Linux Enterprise Server 12 SP5 kernel-source Affected
SUSE Linux Enterprise Server 12 SP5-LTSS kernel-default Affected
SUSE Linux Enterprise Server 12 SP5-LTSS kernel-source Affected
SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security kernel-default Affected
SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security kernel-source Affected
SUSE Linux Enterprise Server 15 SP4 kernel-source Affected
SUSE Linux Enterprise Server 15 SP4-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP4-LTSS kernel-source Affected
SUSE Linux Enterprise Server 15 SP5 kernel-source Affected
SUSE Linux Enterprise Server 15 SP5-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP5-LTSS kernel-source Affected
SUSE Linux Enterprise Server 15 SP6 kernel-source Affected
SUSE Linux Enterprise Server 15 SP6-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP6-LTSS kernel-source Affected
SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-default Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-source Affected
SUSE Manager Proxy 4.3 kernel-source Affected
SUSE Manager Proxy LTS 4.3 kernel-source Affected
SUSE Manager Retail Branch Server 4.3 kernel-source Affected
SUSE Manager Retail Branch Server LTS 4.3 kernel-source Affected
SUSE Manager Server 4.3 kernel-source Affected
SUSE Manager Server LTS 4.3 kernel-source Affected
Products past their end of life and not receiving proactive updates anymore.
SUSE CaaS Platform 4.0 kernel-source Affected
SUSE Enterprise Storage 6 kernel-source Affected
SUSE Enterprise Storage 7 kernel-source Affected
SUSE Enterprise Storage 7.1 kernel-source Affected
SUSE Linux Enterprise Desktop 11 SP4 kernel-source Not affected
SUSE Linux Enterprise Desktop 15 SP1 kernel-source Affected
SUSE Linux Enterprise Desktop 15 SP2 kernel-source Affected
SUSE Linux Enterprise Desktop 15 SP3 kernel-source Affected
SUSE Linux Enterprise Desktop 15 SP4 kernel-source Affected
SUSE Linux Enterprise Desktop 15 SP5 kernel-source Affected
SUSE Linux Enterprise Desktop 15 SP6 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP1 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP2 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP3 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP6 kernel-source Affected
SUSE Linux Enterprise Micro 5.0 kernel-default Affected
SUSE Linux Enterprise Micro 5.1 kernel-default Affected
SUSE Linux Enterprise Micro 5.2 kernel-default Affected
SUSE Linux Enterprise Micro 5.2 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP1 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP2 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP3 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP1 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP2 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP3 kernel-source Affected
SUSE Linux Enterprise Real Time 15 SP2 kernel-source Affected
SUSE Linux Enterprise Real Time 15 SP3 kernel-source Affected
SUSE Linux Enterprise Real Time 15 SP4 kernel-source Affected
SUSE Linux Enterprise Real Time 15 SP4 kernel-source-rt Affected
SUSE Linux Enterprise Real Time 15 SP5 kernel-source-rt Affected
SUSE Linux Enterprise Server 11 SP4 kernel-source Not affected
SUSE Linux Enterprise Server 11 SP4-LTSS kernel-source Not affected
SUSE Linux Enterprise Server 15 SP1 kernel-source Affected
SUSE Linux Enterprise Server 15 SP1-BCL kernel-source Affected
SUSE Linux Enterprise Server 15 SP1-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP1-LTSS kernel-source Affected
SUSE Linux Enterprise Server 15 SP2 kernel-source Affected
SUSE Linux Enterprise Server 15 SP2-BCL kernel-source Affected
SUSE Linux Enterprise Server 15 SP2-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP2-LTSS kernel-source Affected
SUSE Linux Enterprise Server 15 SP3 kernel-source Affected
SUSE Linux Enterprise Server 15 SP3-BCL kernel-source Affected
SUSE Linux Enterprise Server 15 SP3-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP3-LTSS kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP1 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP2 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-default Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-default Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-source Affected
SUSE Manager Proxy 4.0 kernel-source Affected
SUSE Manager Proxy 4.1 kernel-source Affected
SUSE Manager Proxy 4.2 kernel-source Affected
SUSE Manager Retail Branch Server 4.0 kernel-source Affected
SUSE Manager Retail Branch Server 4.1 kernel-source Affected
SUSE Manager Retail Branch Server 4.2 kernel-source Affected
SUSE Manager Server 4.0 kernel-source Affected
SUSE Manager Server 4.1 kernel-source Affected
SUSE Manager Server 4.2 kernel-source Affected
SUSE Real Time Module 15 SP4 kernel-source-rt Affected
SUSE Real Time Module 15 SP5 kernel-source-rt Affected
openSUSE Leap 15.3 kernel-source Affected
openSUSE Leap 15.4 kernel-source Affected
openSUSE Leap 15.4 kernel-source-rt Affected
openSUSE Leap 15.5 kernel-source Affected
openSUSE Leap 15.5 kernel-source-rt Affected
openSUSE Leap 15.6 kernel-source Affected


SUSE Timeline for this CVE

CVE page created: Sun Jul 19 17:30:43 2026
CVE page last modified: Tue Jul 21 13:30:58 2026