SECUFOCUSNOW
Home›CVE index›CVE-2024-36979
Review reviewHigh

CVE-2024-36979

Linux Linux, linux kernel

In the Linux kernel, the following vulnerability has been resolved: net: bridge: mst: fix vlan use-after-free syzbot reported a suspicious rcu usage[1] in bridge's mst code. While fixing it I noticed that nothing prevents a vlan to be freed while walking the list from the same path (br forward delay timer). Fix the rcu usage and also make sure we are not accessing freed memory by making br_mst_vlan_set_state use rcu read lock. [1] WARNING: suspicious RCU usage 6.9.0-rc6-syzkaller #0 Not tainted ----------------------------- net/bridge/br_private.h:1599 suspicious rcu_dereference_protected()...

CVSS
7.8
EPSS
0.26%
17.2% percentile
CISA KEV
Not listed
Published
2024.06.19
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.26%
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: net: bridge: mst: fix vlan use-after-free syzbot reported a suspicious rcu usage[1] in bridge's mst code. While fixing it I noticed that nothing prevents a vlan to be freed while walking the list from the same path (br forward delay timer). Fix the rcu usage and also make sure we are not accessing freed memory by making br_mst_vlan_set_state use rcu read lock. [1] WARNING: suspicious RCU usage 6.9.0-rc6-syzkaller #0 Not tainted ----------------------------- net/bridge/br_private.h:1599 suspicious rcu_dereference_protected()...

Affected product and versions

Product
Linux Linux, linux kernel
Affected versions
>= ec7328b59176227216c461601c6bd0e922232a9b < 8ca9a750fc711911ef616ceb627d07357b04545e, >= ec7328b59176227216c461601c6bd0e922232a9b < 4488617e5e995a09abe4d81add5fb165674edb59, >= ec7328b59176227216c461601c6bd0e922232a9b < a2b01e65d9ba8af2bb086d3b7288ca53a07249ac, >= ec7328b59176227216c461601c6bd0e922232a9b < e43dd2b1ec746e105b7db5f9ad6ef14685a615a4, >= ec7328b59176227216c461601c6bd0e922232a9b < 3a7c1661ae1383364cd6092d851f5e5da64d476b, >= 5.18, >= 5.18 < 6.1.93, >= 6.2 < 6.6.33, >= 6.7 < 6.8.12, >= 6.9 < 6.9.3
Fixed versions
6.1.93, 6.6.33, 6.8.12, 6.9.3

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux Linux, linux kernel and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-416