high CVSS 7.8

CVE-2022-49711·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: bus: fsl-mc-bus: fix KASAN use-after-free in fsl_mc_bus_remove() In fsl_mc_bus_remove(), mc->root_mc_bus_dev->mc_io is passed to fsl_destroy_mc_io(). However, mc->root_mc_bus_dev is already freed in fsl_mc_device_remove(). Then reference to mc->root_mc_bus_dev->mc_io triggers KASAN use-after-free. To avoid the use-after-free, keep the reference to mc->root_mc_bus_dev->mc_io in a local variable and pass to fsl_destroy_mc_io(). This patch needs rework to apply to kernels older than v5.15.

Severity
high
Software
Kernel
Fixed in
5.18.6
Published
2025-02-26

Affected versions

From: 5.16

Until: 5.18.6

Fixed in: 5.18.6

How to fix this CVE

Update your Linux kernel to version 5.18.6 or later to resolve a use-after-free memory safety issue in the Freescale MC bus driver that could allow local privilege escalation. Systems running kernel versions 5.16 through 5.18.5 should prioritize this update, as the vulnerability affects memory handling during bus device removal operations.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Check your current kernel version: uname -r
  2. Verify if Freescale MC bus driver is loaded: lsmod | grep fsl_mc
  3. Search system logs for memory-related errors: dmesg | grep -i 'kasan\|use-after-free\|fsl_mc'
  4. Confirm the patch was applied by checking if kernel version is 5.18.6 or later: uname -r | grep -E '5\.18\.[6-9]|5\.1[9-9]|5\.[2-9][0-9]|[6-9]\.'
  5. Review syslog for any MC bus device removal operations: grep -i 'fsl_mc_bus_remove' /var/log/syslog || journalctl -u kernel | grep -i fsl_mc

FAQ

What is CVE-2022-49711?

This vulnerability is a use-after-free memory bug in the Linux kernel's Freescale MC (Management Complex) bus driver that occurs when the root MC bus device is freed but its I/O memory interface reference is still accessed during cleanup, potentially allowing local attackers to escalate privileges.

Is CVE-2022-49711 being actively exploited?

No, CVE-2022-49711 is not actively exploited in the wild according to CISA's Known Exploited Vulnerabilities catalog, and no public exploit code is currently available.

What versions of Kernel are affected by CVE-2022-49711?

Linux kernel versions 5.16 through 5.18.5 are affected. The vulnerability was patched in kernel 5.18.6 and later versions.

How do I check if my server is vulnerable to CVE-2022-49711?

Run 'uname -r' to check your kernel version; if it shows 5.16.x through 5.18.5, your system is vulnerable. Additionally, verify the Freescale MC bus driver is in use with 'lsmod | grep fsl_mc'.

Does Defensia detect CVE-2022-49711?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2022-49711 will appear in your dashboard with remediation steps.

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References

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