Vulnerability in Kernel (CVE-2022-49049)

Summary

Vulnerability in Kernel (CVE-2022-49049). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 5.15.35, 5.17.4 or later.

Original description

The description as published by the source.

In the Linux kernel, the following vulnerability has been resolved:

mm/secretmem: fix panic when growing a memfd_secret

When one tries to grow an existing memfd_secret with ftruncate, one gets
a panic [1]. For example, doing the following reliably induces the
panic:

fd = memfd_secret();

ftruncate(fd, 10);
ptr = mmap(NULL, 10, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
strcpy(ptr, "123456789");

munmap(ptr, 10);
ftruncate(fd, 20);

The basic reason for this is, when we grow with ftruncate, we call down
into simple_setattr, and then truncate_inode_pages_range, and eventually
we try to zero part of the memory. The normal truncation code does this
via the direct map (i.e., it calls page_address() and hands that to
memset()).

For memfd_secret though, we specifically don't map our pages via the
direct map (i.e. we call set_direct_map_invalid_noflush() on every
fault). So the address returned by page_address() isn't useful, and
when we try to memset() with it we panic.

This patch avoids the panic by implementing a custom setattr for
memfd_secret, which detects resizes specifically (setting the size for
the first time works just fine, since there are no existing pages to try
to zero), and rejects them with EINVAL.

One could argue growing should be supported, but I think that will
require a significantly more lengthy change. So, I propose a minimal
fix for the benefit of stable kernels, and then perhaps to extend
memfd_secret to support growing in…

Source: OSV.dev (Open Source Vulnerabilities) NVD OSV

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-2022-49049 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 5.15.35, 5.17.4 or later.
If unsure, ask your IT team or search "Kernel CVE-2022-49049" on the vendor's site.

CVE-2022-49049 (Kernel)
Patched: 5.15.35, 5.17.4 — apply immediately
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.

❓ What is the problem

A vulnerability (unclassified) exists in Kernel.

📍 Affected scope

Check the vendor advisory for the affected versions of Kernel.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 5.15.35, 5.17.4.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Kernel' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'Kernel' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で Kernel を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade Kernel to 5.15.35, 5.17.4
```
ステージング環境で 5.15.35, 5.17.4 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
Post-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

Linux Kernel

[{"type":"ECOSYSTEM","events":[{"introduced":"5.14.0"},{"fixed":"5.15.35"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"5.17.4"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

Debian DEBIAN-CVE-2022-49049 linux Fixed in: 5.17.6-1
Ubuntu UBUNTU-CVE-2022-49049 linux