Vulnerability in Kernel (CVE-2024-49873)

Summary

Vulnerability in Kernel (CVE-2024-49873). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.11.3 or later.

Original description

The description as published by the source.

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

mm/filemap: fix filemap_get_folios_contig THP panic

Patch series "memfd-pin huge page fixes".

Fix multiple bugs that occur when using memfd_pin_folios with hugetlb
pages and THP. The hugetlb bugs only bite when the page is not yet
faulted in when memfd_pin_folios is called. The THP bug bites when the
starting offset passed to memfd_pin_folios is not huge page aligned. See
the commit messages for details.

This patch (of 5):

memfd_pin_folios on memory backed by THP panics if the requested start
offset is not huge page aligned:

BUG: kernel NULL pointer dereference, address: 0000000000000036
RIP: 0010:filemap_get_folios_contig+0xdf/0x290
RSP: 0018:ffffc9002092fbe8 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 0000000000000002 RCX: 0000000000000002

The fault occurs here, because xas_load returns a folio with value 2:

filemap_get_folios_contig()
    for (folio = xas_load(&xas); folio && xas.xa_index <= end;
                    folio = xas_next(&xas)) {
            ...
            if (!folio_try_get(folio))   <-- BOOM

"2" is an xarray sibling entry. We get it because memfd_pin_folios does
not round the indices passed to filemap_get_folios_contig to huge page
boundaries for THP, so we load from the middle of a huge page range see a
sibling. (It does round for hugetlbfs, at the is_file_hugepages test).

To fix, if the folio is a sibling, then return the next index as the
starting point…

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-2024-49873 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.11.3 or later.
If unsure, ask your IT team or search "Kernel CVE-2024-49873" on the vendor's site.

CVE-2024-49873 (Kernel)
Patched: 6.11.3 — 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 6.11.3.

🛡️ 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 6.11.3
```
ステージング環境で 6.11.3 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":"6.11.0"},{"fixed":"6.11.3"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

Debian DEBIAN-CVE-2024-49873 linux Fixed in: 6.11.4-1