CVE-2026-31697
Published: May 1, 2026· Updated: May 6, 2026
Official Description
In the Linux kernel, the following vulnerability has been resolved:
crypto: ccp: Don't attempt to copy ID to userspace if PSP command failed
When retrieving the ID for the CPU, don't attempt to copy the ID blob to
userspace if the firmware command failed. If the failure was due to an
invalid length, i.e. the userspace buffer+length was too small, copying
the number of bytes _firmware_ requires will overflow the kernel-allocated
buffer and leak data to userspace.
BUG: KASAN: slab-out-of-bounds in instrument_copy_to_user ../include/linux/instrumented.h:129 [inline]
BUG: KASAN: slab-out-of-bounds in _inline_copy_to_user ../include/linux/uaccess.h:205 [inline]
BUG: KASAN: slab-out-of-bounds in _copy_to_user+0x66/0xa0 ../lib/usercopy.c:26
Read of size 64 at addr ffff8881867f5960 by task syz.0.906/24388
CPU: 130 UID: 0 PID: 24388 Comm: syz.0.906 Tainted: G U O 7.0.0-smp-DEV #28 PREEMPTLAZY
Tainted: [U]=USER, [O]=OOT_MODULE
Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 12.62.0-0 11/19/2025
Call Trace:
<TASK>
dump_stack_lvl+0xc5/0x110 ../lib/dump_stack.c:120
print_address_description ../mm/kasan/report.c:378 [inline]
print_report+0xbc/0x260 ../mm/kasan/report.c:482
kasan_report+0xa2/0xe0 ../mm/kasan/report.c:595
check_region_inline ../mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x264/0x2c0 ../mm/kasan/generic.c:200
instrument_copy_to_user ../include/linux/instrumented.h:129 [inline]
_inline_copy_to_user ../include/linux/uaccess.h:205 [inline]
_copy_to_user+0x66/0xa0 ../lib/usercopy.c:26
copy_to_user ../include/linux/uaccess.h:236 [inline]
sev_ioctl_do_get_id2+0x361/0x490 ../drivers/crypto/ccp/sev-dev.c:2222
sev_ioctl+0x25f/0x490 ../drivers/crypto/ccp/sev-dev.c:2575
vfs_ioctl ../fs/ioctl.c:51 [inline]
__do_sys_ioctl ../fs/ioctl.c:597 [inline]
__se_sys_ioctl+0x11d/0x1b0 ../fs/ioctl.c:583
do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe0/0x800 ../arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
</TASK>
WARN if the driver says the command succeeded, but the firmware error code
says otherwise, as __sev_do_cmd_locked() is expected to return -EIO on any
firwmware error.
Technical Analysis
CVE-2026-31697 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
A successful exploit results in complete confidentiality breach (data exposure), availability disruption (denial of service), with a CVSS base score of 7.1.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (5)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-31697 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts