Use After Free Affecting kernel-default-extra package, versions <6.4.0-150600.23.7.3


Severity

Recommended
0.0
medium
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.04% (15th percentile)

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  • Snyk IDSNYK-SLES156-KERNELDEFAULTEXTRA-7716250
  • published20 Aug 2024
  • disclosed25 Jun 2024

Introduced: 25 Jun 2024

CVE-2024-35811  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade SLES:15.6 kernel-default-extra to version 6.4.0-150600.23.7.3 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-default-extra package and not the kernel-default-extra package as distributed by SLES. See How to fix? for SLES:15.6 relevant fixed versions and status.

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

wifi: brcmfmac: Fix use-after-free bug in brcmf_cfg80211_detach

This is the candidate patch of CVE-2023-47233 : https://nvd.nist.gov/vuln/detail/CVE-2023-47233

In brcm80211 driver,it starts with the following invoking chain to start init a timeout worker:

->brcmf_usb_probe ->brcmf_usb_probe_cb ->brcmf_attach ->brcmf_bus_started ->brcmf_cfg80211_attach ->wl_init_priv ->brcmf_init_escan ->INIT_WORK(&cfg->escan_timeout_work, brcmf_cfg80211_escan_timeout_worker);

If we disconnect the USB by hotplug, it will call brcmf_usb_disconnect to make cleanup. The invoking chain is :

brcmf_usb_disconnect ->brcmf_usb_disconnect_cb ->brcmf_detach ->brcmf_cfg80211_detach ->kfree(cfg);

While the timeout woker may still be running. This will cause a use-after-free bug on cfg in brcmf_cfg80211_escan_timeout_worker.

Fix it by deleting the timer and canceling the worker in brcmf_cfg80211_detach.

[arend.vanspriel@broadcom.com: keep timer delete as is and cancel work just before free]

CVSS Scores

version 3.1