CVE-2022-49995 | writeback: avoid use-after-free after removing device

In the Linux kernel, the following vulnerability has been resolved: writeback: avoid use-after-free after removing device When a disk is removed, bdi_unregister gets called to stop further writeback and wait for associated delayed work to complete. However, wb_inode_writeback_end() may schedule bandwidth estimation dwork after this has completed, which can result in the timer attempting to access the just freed bdi_writeback. Fix this by checking if the bdi_writeback is alive, similar to when scheduling writeback work. Since this requires wb->work_lock, and wb_inode_writeback_end() may get called from interrupt, switch wb->work_lock to an irqsafe lock.

Published: 2025-06-18 Last update: 2025-11-14 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-2022-49995 is rated Low Risk (36.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.05%). 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-2022-49995

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 2026-04-14 0.02% 0.05% +0.03%
2 2025-06-18 — 0.02% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-49995

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]

Weakness enumeration for CVE-2022-49995

OS Trackers for CVE-2022-49995

vendor priority summary link
debian unimportant CVE-2022-49995 unimportant 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-2022-49995
redhat medium — https://access.redhat.com/security/cve/CVE-2022-49995
suse medium — https://www.suse.com/security/cve/CVE-2022-49995/
ubuntu medium CVE-2022-49995 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, ignored 147, not-affected 144, released 114, needs-triage 1. https://ubuntu.com/security/CVE-2022-49995

Affected software / configurations for CVE-2022-49995

Vendor Product Version Raw CPE
linux linux_kernel >= 5.15, < 5.15.64 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.16, < 5.19.6 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 6.0 cpe:2.3:o:linux:linux_kernel:6.0:rc1:*:*:*:*:*:*
linux linux_kernel 6.0 cpe:2.3:o:linux:linux_kernel:6.0:rc2:*:*:*:*:*:*

References for CVE-2022-49995

cvelogic Threat Intelligence