CyberSecBulletin
CVE-2022-50115NVD status: Analyzed

Linux: Double Free

Published Updated By the CyberSecBulletin desk

CVE-2022-50115 is a high-severity double free vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 8463986b54295e6b65ddf2b7c65627d01ce7643b, c2eddfcafcffaf1b9245ea0dde9143bbfb47d5d1, d5bd47f3ca124058a8e87eae4508afeda2132611 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.21% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 8463986b54295e6b65ddf2b7c65627d01ce7643b or c2eddfcafcffaf1b9245ea0dde9143bbfb47d5d1 or d5bd47f3ca124058a8e87eae4508afeda2132611, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.18.18 or 5.19.2, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxb5cee8feb1d482a9d07b677f4f2f9565bacda53e up to, but not including, 8463986b54295e6b65ddf2b7c65627d01ce7643b; b5cee8feb1d482a9d07b677f4f2f9565bacda53e up to, but not including, c2eddfcafcffaf1b9245ea0dde9143bbfb47d5d1; b5cee8feb1d482a9d07b677f4f2f9565bacda53e up to, but not including, d5bd47f3ca124058a8e87eae4508afeda2132611; 5.188463986b54295e6b65ddf2b7c65627d01ce7643b, c2eddfcafcffaf1b9245ea0dde9143bbfb47d5d1, d5bd47f3ca124058a8e87eae4508afeda2132611
LinuxLinux Kernel5.18 up to, but not including, 5.18.18; 5.19 up to, but not including, 5.19.25.18.18, 5.19.2

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Official description

In the Linux kernel, the following vulnerability has been resolved: ASoC: SOF: ipc3-topology: Prevent double freeing of ipc_control_data via load_bytes We have sanity checks for byte controls and if any of the fail the locally allocated scontrol->ipc_control_data is freed up, but not set to NULL. On a rollback path of the error the higher level code will also try to free the scontrol->ipc_control_data which will eventually going to lead to memory corruption as double freeing memory is not a good thing.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Double Free

The product calls free() twice on the same memory address.

How developers prevent this class of flaw

  • Choose a language that provides automatic memory management.
  • Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
  • Use a static analysis tool to find double free instances.

More Double Free vulnerabilities (CWE-415)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Recent Double Free vulnerabilities

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