CVE-2022-49556 | KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent kernel data leak

In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent kernel data leak For some sev ioctl interfaces, the length parameter that is passed maybe less than or equal to SEV_FW_BLOB_MAX_SIZE, but larger than the data that PSP firmware returns. In this case, kmalloc will allocate memory that is the size of the input rather than the size of the data. Since PSP firmware doesn't fully overwrite the allocated buffer, these sev ioctl interface may return uninitialized kernel slab memory.

Published: 2025-02-26 Last update: 2026-01-22 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-49556 is rated Low Risk (36.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.08%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2022-49556

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-06 0.04% 0.08% +0.05%
2 2026-01-23 0.05% 0.04% -0.01%
3 2025-09-22 — 0.05% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-49556

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.1 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.2 [email protected]

Weakness enumeration for CVE-2022-49556

OS Trackers for CVE-2022-49556

vendor priority summary link
debian not yet assigned CVE-2022-49556 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2022-49556
redhat medium — https://access.redhat.com/security/cve/CVE-2022-49556
suse medium — https://www.suse.com/security/cve/CVE-2022-49556/
ubuntu medium CVE-2022-49556 medium priority: Ubuntu including 130 source packages (linux, linux-allwinner-5.19, …), 1040 status rows across 8 suites (bionic, focal, jammy, noble, oracular, trusty, upstream, xenial): DNE 713, ignored 146, not-affected 95, released 86. https://ubuntu.com/security/CVE-2022-49556

Affected software / configurations for CVE-2022-49556

Vendor Product Version Raw CPE
linux linux_kernel >= 5.7, < 5.10.124 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.11, < 5.15.45 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.16, < 5.17.13 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.18, < 5.18.2 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

References for CVE-2022-49556

cvelogic Threat Intelligence