Vulnerability in Kernel (CVE-2024-36892)
Summary
Vulnerability in Kernel (CVE-2024-36892). Risk of unauthorized operations or information disclosure. Exploitable via init_on_free. Mitigation: upgrade to 6.8.10 or later.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
mm/slub: avoid zeroing outside-object freepointer for single free
Commit 284f17ac13fe ("mm/slub: handle bulk and single object freeing
separately") splits single and bulk object freeing in two functions
slab_free() and slab_free_bulk() which leads slab_free() to call
slab_free_hook() directly instead of slab_free_freelist_hook().
If init_on_free is set, slab_free_hook() zeroes the object.
Afterward, if slub_debug=F and CONFIG_SLAB_FREELIST_HARDENED are
set, the do_slab_free() slowpath executes freelist consistency
checks and try to decode a zeroed freepointer which leads to a
"Freepointer corrupt" detection in check_object().
During bulk free, slab_free_freelist_hook() isn't affected as it always
sets it objects freepointer using set_freepointer() to maintain its
reconstructed freelist after init_on_free.
For single free, object's freepointer thus needs to be avoided when
stored outside the object if init_on_free is set. The freepointer left
as is, check_object() may later detect an invalid pointer value due to
objects overflow.
To reproduce, set slub_debug=FU init_on_free=1 log_level=7 on the
command line of a kernel build with CONFIG_SLAB_FREELIST_HARDENED=y.
dmesg sample log:
[ 10.708715] =============================================================================
[ 10.710323] BUG kmalloc-rnd-05-32 (Tainted: G B T ): Freepointer corrupt
[ 10.712695] ----------------…
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-2024-36892 has been found in Kernel.
Attackers can target a specific entry point like init_on_free over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.8.10 or later.
If unsure, ask your IT team or search "Kernel CVE-2024-36892" on the vendor's site.
CVE-2024-36892 (Kernel)
Attack surface: init_on_free / CONFIG_SLAB_FREELIST_HARDENED
Patched: 6.8.10 — 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.
A vulnerability (unclassified) exists in Kernel. Attackers reach the vulnerable code path via init_on_free.
Check the vendor advisory for the affected versions of Kernel. Attack surface: init_on_free / CONFIG_SLAB_FREELIST_HARDENED.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 6.8.10.
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. 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
-
1Identify 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。 -
2Apply patch patch
Upgrade Kernel to 6.8.10ステージング環境で 6.8.10 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。
-
3Post-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-2024-36892 linux Fixed in: 6.8.11-1
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org