crypto: ccp: Don't attempt to copy CSR to userspace if PSP command failed
Summary
| CVE | CVE-2026-31699 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-01 14:16:19 UTC |
| Updated | 2026-05-03 07:16:17 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: crypto: ccp: Don't attempt to copy CSR to userspace if PSP command failed When retrieving the PEK CSR, don't attempt to copy the 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 2084 at addr ffff898144612e20 by task syz.9.219/21405 CPU: 14 UID: 0 PID: 21405 Comm: syz.9.219 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_pek_csr+0x31f/0x590 ../drivers/crypto/ccp/sev-dev.c:1872 sev_ioctl+0x3a4/0x490 ../drivers/crypto/ccp/sev-dev.c:2562 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. |
Risk And Classification
Primary CVSS: v3.1 7.1 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
EPSS: 0.000180000 probability, percentile 0.048520000 (date 2026-05-02)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Secondary | 7.1 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H |
| 3.1 | CNA | DECLARED | 7.1 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
NoneAvailability
HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected e799035609e1526761aa2f896a974b233d04d36d 607ba280f2adb5092cf5386c3935afac2ca0031a git | Not specified |
| CNA | Linux | Linux | affected e799035609e1526761aa2f896a974b233d04d36d 59e9ae81f8670ccc780bc75f45a355736f640ec9 git | Not specified |
| CNA | Linux | Linux | affected e799035609e1526761aa2f896a974b233d04d36d 111dcc6d0f016076745824a787d25609d0022f4c git | Not specified |
| CNA | Linux | Linux | affected e799035609e1526761aa2f896a974b233d04d36d 3b4fd8f15765d9a3105b834dba8a05d025e5e16e git | Not specified |
| CNA | Linux | Linux | affected e799035609e1526761aa2f896a974b233d04d36d abe4a6d6f606113251868c2c4a06ba904bb41eed git | Not specified |
| CNA | Linux | Linux | affected 4.16 | Not specified |
| CNA | Linux | Linux | unaffected 4.16 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.136 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.84 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.25 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0.2 7.0.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1-rc1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/3b4fd8f15765d9a3105b834dba8a05d025e5e16e | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/111dcc6d0f016076745824a787d25609d0022f4c | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/59e9ae81f8670ccc780bc75f45a355736f640ec9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/607ba280f2adb5092cf5386c3935afac2ca0031a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/abe4a6d6f606113251868c2c4a06ba904bb41eed | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.