Use-After-Free in Linux kernel (CVE-2024-53095)
Summary
Vulnerability in Linux kernel (CVE-2024-53095). 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:
smb: client: Fix use-after-free of network namespace.
Recently, we got a customer report that CIFS triggers oops while
reconnecting to a server. [0]
The workload runs on Kubernetes, and some pods mount CIFS servers
in non-root network namespaces. The problem rarely happened, but
it was always while the pod was dying.
The root cause is wrong reference counting for network namespace.
CIFS uses kernel sockets, which do not hold refcnt of the netns that
the socket belongs to. That means CIFS must ensure the socket is
always freed before its netns; otherwise, use-after-free happens.
The repro steps are roughly:
- mount CIFS in a non-root netns
- drop packets from the netns
- destroy the netns
- unmount CIFS
We can reproduce the issue quickly with the script [1] below and see
the splat [2] if CONFIG_NET_NS_REFCNT_TRACKER is enabled.
When the socket is TCP, it is hard to guarantee the netns lifetime
without holding refcnt due to async timers.
Let's hold netns refcnt for each socket as done for SMC in commit
9744d2bf1976 ("smc: Fix use-after-free in tcp_write_timer_handler().").
Note that we need to move put_net() from cifs_put_tcp_session() to
clean_demultiplex_info(); otherwise, __sock_create() still could touch a
freed netns while cifsd tries to reconnect from cifs_demultiplex_thread().
Also, maybe_get_net() cannot be put just before __sock_create() because
the code is not under RCU and…
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-2024-53095 has been found in Linux kernel.
Successful exploitation can lead to full system takeover. CVSS score: 9.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2024-53095" on the vendor's site.
CVE-2024-53095 (Linux kernel) — CWE-416 / CVSS v3 9.8
Attack vector: remote (network-reachable) / unauthenticated / 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: Critical (CVSS 9.8/10). 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
- BellSoft Alpaquita BELL-CVE-2024-53095 linux-lts
- Debian DEBIAN-CVE-2024-53095 linux
- Ubuntu UBUNTU-CVE-2024-53095 linux-aws
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org