high CVSS 7.8 EPSS <0.1%

CVE-2022-49493·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: ASoC: rt5645: Fix errorenous cleanup order There is a logic error when removing rt5645 device as the function rt5645_i2c_remove() first cancel the &rt5645->jack_detect_work and delete the &rt5645->btn_check_timer latter. However, since the timer handler rt5645_btn_check_callback() will re-queue the jack_detect_work, this cleanup order is buggy. That is, once the del_timer_sync in rt5645_i2c_remove is concurrently run with the rt5645_btn_check_callback, the canceled jack_detect_work will be rescheduled again, leading to possible use-after-free. This patch fix the issue by placing the del_timer_sync function before the cancel_delayed_work_sync.

Severity
high
Software
Kernel
Fixed in
5.18.3
Published

How likely is exploitation

FIRST's Exploit Prediction Scoring System puts the probability of this CVE being exploited in the next 30 days at <0.1% — higher than 13% of all published CVEs. EPSS is an independent forecast of exploitation, not a severity rating: it says nothing about how much damage a successful attack does, which is what a CVSS score measures.

Read the two together. CVE-2022-49493 scores 7.8 on CVSS, so a successful attack would be serious — but at <0.1%, almost nobody is currently attempting it. That is a different situation from a flaw under mass exploitation, and it is usually the difference between patching on your next maintenance window and patching tonight.

Affected versions

From: 5.18

Until: 5.18.3

Fixed in: 5.18.3

How to fix this CVE

Update your Linux kernel to version 5.18.3 or later to fix a critical device removal race condition in the rt5645 audio codec driver. The vulnerability occurs when the jack detection timer and work queue are cleaned up in the wrong order during device removal, potentially causing use-after-free memory access. Apply the kernel update through your distribution's package manager and reboot to activate the patched version.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Run `uname -r` to check your current kernel version. Versions 5.18 through 5.18.2 are vulnerable.
  2. Check if the rt5645 audio codec driver is loaded by running `lsmod | grep rt5645`. If present, your hardware uses the affected component.
  3. Search system logs for jack detection or rt5645-related errors using `grep -i 'rt5645\|jack\|audio' /var/log/kern.log` or `journalctl -k | grep -i rt5645`.
  4. After patching, verify the kernel version with `uname -r` to confirm it is 5.18.3 or later, and reboot if the update has not yet taken effect.

FAQ

What is CVE-2022-49493?

CVE-2022-49493 is a race condition in the Linux kernel's rt5645 audio codec driver where incorrect cleanup ordering during device removal allows a timer callback to reschedule a work queue after it has been canceled, leading to potential use-after-free memory corruption.

Is CVE-2022-49493 being actively exploited?

No, CVE-2022-49493 is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are currently available.

What versions of Kernel are affected by CVE-2022-49493?

Linux kernel versions 5.18, 5.18.1, and 5.18.2 are vulnerable. The issue is fixed in kernel 5.18.3 and later.

How do I check if my server is vulnerable to CVE-2022-49493?

Run `uname -r` to display your kernel version. If it shows 5.18.0, 5.18.1, or 5.18.2, you are vulnerable. Additionally, check if the rt5645 audio codec is in use with `lsmod | grep rt5645`.

Does Defensia detect CVE-2022-49493?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If the Linux kernel is installed on a monitored server, CVE-2022-49493 will appear in your dashboard with remediation steps and kernel version details.

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References

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