Use-After-Free in Linux kernel (CVE-2022-50256)
Summary
Vulnerability in Linux kernel (CVE-2022-50256). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
drm/meson: remove drm bridges at aggregate driver unbind time
drm bridges added by meson_encoder_hdmi_init and meson_encoder_cvbs_init
were not manually removed at module unload time, which caused dangling
references to freed memory to remain linked in the global bridge_list.
When loading the driver modules back in, the same functions would again
call drm_bridge_add, and when traversing the global bridge_list, would
end up peeking into freed memory.
Once again KASAN revealed the problem:
[ +0.000095] =============================================================
[ +0.000008] BUG: KASAN: use-after-free in __list_add_valid+0x9c/0x120
[ +0.000018] Read of size 8 at addr ffff00003da291f0 by task modprobe/2483
[ +0.000018] CPU: 3 PID: 2483 Comm: modprobe Tainted: G C O 5.19.0-rc6-lrmbkasan+ #1
[ +0.000011] Hardware name: Hardkernel ODROID-N2Plus (DT)
[ +0.000008] Call trace:
[ +0.000006] dump_backtrace+0x1ec/0x280
[ +0.000012] show_stack+0x24/0x80
[ +0.000008] dump_stack_lvl+0x98/0xd4
[ +0.000011] print_address_description.constprop.0+0x80/0x520
[ +0.000011] print_report+0x128/0x260
[ +0.000008] kasan_report+0xb8/0xfc
[ +0.000008] __asan_report_load8_noabort+0x3c/0x50
[ +0.000009] __list_add_valid+0x9c/0x120
[ +0.000009] drm_bridge_add+0x6c/0x104 [drm]
[ +0.000165] dw_hdmi_probe+0x1900/0x2360 [dw_hdmi]
[ +0.000022] meson_dw_hdmi_bind+0x520/0x814 [meson_dw_hdmi]
[ +0.0…
Source: NIST National Vulnerability Database NVD
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2022-50256 has been found in Linux kernel.
Successful exploitation can lead to full system takeover. CVSS score: 7.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2022-50256" on the vendor's site.
CVE-2022-50256 (Linux kernel) — CWE-416 / CVSS v3 7.8
Attack vector: local / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Use-after-free (CWE-416) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: High (CVSS 7.8/10). Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2022-50256 linux
- Ubuntu UBUNTU-CVE-2022-50256 linux
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org