High severity · published May 1, 2026
CVE-2026-31698
crypto: ccp: Don't attempt to copy PDH cert to userspace if PSP command failed
7.1
CVSS
0.1%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 3% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
4.16 before 6.6.136; 6.7 before 6.12.84; 6.13 before 6.18.25; 6.19 before 7.0.2; 7.1; 7.1 · source: NVD
LI
Linux · Linux
76a2b524a4b1d6dc0f2421f9854a01d55d5e5436 before af67d35da744b6b678c7a0296d9c679658779829; 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436 before 854d7846e1d29f32f1bbeb2e869e794df12067f6; 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436 before 25d9b3446001185484209cf57951f3368462b631; 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436 before b5c14bd4da1f376f385722fe1da993f1edab6472; 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436 before 78b97e43d0b3e674d9d49ae56937b11e2ba3fcaf; 76a2b524a4b1d6dc0f2421f9854a01d55d5e5436 before 051e51aa55fd4cdc3e8283cf4476aeeb5f563274; +3 more · source: vendor
SS
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem · Siemens
0 · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-31698
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-31698
Patch
https://git.kernel.org/stable/c/051e51aa55fd4cdc3e8283cf4476aeeb5f563274
git.kernel.org
https://git.kernel.org/stable/c/25d9b3446001185484209cf57951f3368462b631
Patch
https://git.kernel.org/stable/c/50808c13452dae43a2c90b1bbbf9daa16501ce70
Patch
https://git.kernel.org/stable/c/78b97e43d0b3e674d9d49ae56937b11e2ba3fcaf
git.kernel.org
https://git.kernel.org/stable/c/854d7846e1d29f32f1bbeb2e869e794df12067f6
git.kernel.org
https://git.kernel.org/stable/c/af67d35da744b6b678c7a0296d9c679658779829
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