Out-of-Bounds Read in Linux kernel (CVE-2022-50255)
Summary
Vulnerability in Linux kernel (CVE-2022-50255). 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:
tracing: Fix reading strings from synthetic events
The follow commands caused a crash:
cd /sys/kernel/tracing
echo 's:open char file[]' > dynamic_events
echo 'hist:keys=common_pid:file=filename:onchange($file).trace(open,$file)' > events/syscalls/sys_enter_openat/trigger'
echo 1 > events/synthetic/open/enable
BOOM!
The problem is that the synthetic event field "char file[]" will read
the value given to it as a string without any memory checks to make sure
the address is valid. The above example will pass in the user space
address and the sythetic event code will happily call strlen() on it
and then strscpy() where either one will cause an oops when accessing
user space addresses.
Use the helper functions from trace_kprobe and trace_eprobe that can
read strings safely (and actually succeed when the address is from user
space and the memory is mapped in).
Now the above can show:
packagekitd-1721 [000] ...2. 104.597170: open: file=/usr/lib/rpm/fileattrs/cmake.attr
in:imjournal-978 [006] ...2. 104.599642: open: file=/var/lib/rsyslog/imjournal.state.tmp
packagekitd-1721 [000] ...2. 104.626308: open: file=/usr/lib/rpm/fileattrs/debuginfo.attr
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-2022-50255 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-2022-50255" on the vendor's site.
CVE-2022-50255 (Linux kernel) — CWE-125 / 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.
Out-of-bounds read (CWE-125) 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-2022-50255 linux
- Ubuntu UBUNTU-CVE-2022-50255 linux-hwe-edge
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org