CVE-2026-31698

Advisory lineage Upstream: 0 Downstream: 5
Modified
Published: 01 May 2026, 13:55
Last modified:01 Jun 2026, 16:13

Vulnerability Summary

Overall Risk (default)
medium
28/100
CVSS Score
7.1 HIGH
v3.1 (cve.org)
EPSS Score
0.01% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

01 May 2026, 13:55
Published
Vulnerability first disclosed
01 Jun 2026, 16:13
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: crypto: ccp: Don't attempt to copy PDH cert to userspace if PSP command failed When retrieving the PDH cert, don't attempt to copy the blobs 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 2084 at addr ffff8885c4ab8aa0 by task syz.0.186/21033 CPU: 51 UID: 0 PID: 21033 Comm: syz.0.186 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 34.84.12-0 11/17/2025 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_pdh_export+0x3d3/0x7c0 ../drivers/crypto/ccp/sev-dev.c:2347 sev_ioctl+0x2a2/0x490 ../drivers/crypto/ccp/sev-dev.c:2568 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.

CVSS Metrics

  • v3.1•HIGH•Score: 7.1CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

EPSS Trends

Current EPSS score: 0.01%• Percentile: 4%

Techniques & Countermeasures

  • CWE-787•Out-of-bounds Write

    The product writes data past the end, or before the beginning, of the intended buffer.

Affected Systems

  • linux•linux

    ≥ 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436, < af67d35da744b6b678c7a0296d9c679658779829 | ≥ 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436, < 854d7846e1d29f32f1bbeb2e869e794df12067f6 | ≥ 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436, < 25d9b3446001185484209cf57951f3368462b631 | ≥ 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436, < b5c14bd4da1f376f385722fe1da993f1edab6472 | ≥ 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436, < 78b97e43d0b3e674d9d49ae56937b11e2ba3fcaf | ≥ 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436, < 051e51aa55fd4cdc3e8283cf4476aeeb5f563274 | ≥ 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436, < 50808c13452dae43a2c90b1bbbf9daa16501ce70 | ≥ 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436, < e76239fed3cffd6d304d8ca3ce23984fd24f57d3 | 4.16

  • linux•linux_kernel

    ≥ 4.16, < 6.6.136 | ≥ 6.7, < 6.12.84 | ≥ 6.13, < 6.18.25 | ≥ 6.19, < 7.0.2 | 7.1:rc1 | 7.1:rc2

References (8)