---
id: CVE-2024-35895
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bpf, sockmap: Prevent lock inversion deadlock in map delete elem

  syzkaller started using corpuses where a BPF tracing program deletes
  elements from a sockmap/sockhash …
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bpf, sockmap: Prevent lock inversion deadlock in map delete elem

  syzkaller started using corpuses where a BPF tracing program deletes
  elements from a sockmap/sockhash …
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-667
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 4.20, < 5.4.274'
  - 'linux_kernel >= 5.5, < 5.10.215'
  - 'linux_kernel >= 5.11, < 5.15.154'
  - 'linux_kernel >= 5.16, < 6.1.85'
  - 'linux_kernel >= 6.2, < 6.6.26'
  - 'linux_kernel >= 6.7, < 6.8.5'
  - linux_kernel = 6.9
  - debian_linux = 10.0
patched:
  - linux_kernel 6.8.5
published: '2024-05-19'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T01:17:50.647'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2024-35895'
references:
  - url: 'https://git.kernel.org/stable/c/668b3074aa14829e2ac2759799537a93b60fef86'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/6af057ccdd8e7619960aca1f0428339f213b31cd'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a44770fed86515eedb5a7c00b787f847ebb134a5'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d1e73fb19a4c872d7a399ad3c66e8ca30e0875ec'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/dd54b48db0c822ae7b520bc80751f0a0a173ef75'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f7990498b05ac41f7d6a190dc0418ef1d21bf058'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ff91059932401894e6c86341915615c5eb0eca48'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/668b3074aa14829e2ac2759799537a93b60fef86'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/6af057ccdd8e7619960aca1f0428339f213b31cd'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/a44770fed86515eedb5a7c00b787f847ebb134a5'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/d1e73fb19a4c872d7a399ad3c66e8ca30e0875ec'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/dd54b48db0c822ae7b520bc80751f0a0a173ef75'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/f7990498b05ac41f7d6a190dc0418ef1d21bf058'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/ff91059932401894e6c86341915615c5eb0eca48'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-265688.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.00182
epssPercentile: 0.07713
ingestedAt: '2026-10-15T03:30:12.684Z'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2024-05-23T19:25:39.256006Z'
---

## Overview

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

bpf, sockmap: Prevent lock inversion deadlock in map delete elem

syzkaller started using corpuses where a BPF tracing program deletes
elements from a sockmap/sockhash map. Because BPF tracing programs can be
invoked from any interrupt context, locks taken during a map_delete_elem
operation must be hardirq-safe. Otherwise a deadlock due to lock inversion
is possible, as reported by lockdep:

       CPU0                    CPU1
       ----                    ----
  lock(&htab->buckets[i].lock);
                               local_irq_disable();
                               lock(&host->lock);
                               lock(&htab->buckets[i].lock);
  <Interrupt>
    lock(&host->lock);

Locks in sockmap are hardirq-unsafe by design. We expects elements to be
deleted from sockmap/sockhash only in task (normal) context with interrupts
enabled, or in softirq context.

Detect when map_delete_elem operation is invoked from a context which is
_not_ hardirq-unsafe, that is interrupts are disabled, and bail out with an
error.

Note that map updates are not affected by this issue. BPF verifier does not
allow updating sockmap/sockhash from a BPF tracing program today.

## Affected

- `linux_kernel >= 4.20, < 5.4.274`
- `linux_kernel >= 5.5, < 5.10.215`
- `linux_kernel >= 5.11, < 5.15.154`
- `linux_kernel >= 5.16, < 6.1.85`
- `linux_kernel >= 6.2, < 6.6.26`
- `linux_kernel >= 6.7, < 6.8.5`
- `linux_kernel = 6.9`
- `debian_linux = 10.0`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.8.5`