high CVSS 7.8 EPSS 0.12%

CVE-2022-49223·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: cxl/port: Hold port reference until decoder release KASAN + DEBUG_KOBJECT_RELEASE reports a potential use-after-free in cxl_decoder_release() where it goes to reference its parent, a cxl_port, to free its id back to port->decoder_ida. BUG: KASAN: use-after-free in to_cxl_port+0x18/0x90 [cxl_core] Read of size 8 at addr ffff888119270908 by task kworker/35:2/379 CPU: 35 PID: 379 Comm: kworker/35:2 Tainted: G OE 5.17.0-rc2+ #198 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Workqueue: events kobject_delayed_cleanup Call Trace: <TASK> dump_stack_lvl+0x59/0x73 print_address_description.constprop.0+0x1f/0x150 ? to_cxl_port+0x18/0x90 [cxl_core] kasan_report.cold+0x83/0xdf ? to_cxl_port+0x18/0x90 [cxl_core] to_cxl_port+0x18/0x90 [cxl_core] cxl_decoder_release+0x2a/0x60 [cxl_core] device_release+0x5f/0x100 kobject_cleanup+0x80/0x1c0 The device core only guarantees parent lifetime until all children are unregistered. If a child needs a parent to complete its ->release() callback that child needs to hold a reference to extend the lifetime of the parent.

Severity
high
Software
Kernel
Fixed in
5.17.2
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 0.12% — higher than 30% 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-2022-49223 scores 7.8 on CVSS, so a successful attack would be serious — but at 0.12%, 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: 5.17

Until: 5.17.2

Fixed in: 5.17.2

How to fix this CVE

Update your Linux kernel to version 5.17.2 or later to resolve this use-after-free vulnerability in the CXL port decoder release path. The fix ensures the port object remains available until the decoder completes its cleanup, preventing kernel memory corruption. Systems running kernel versions 5.17 through 5.17.1 with CXL/persistent memory support enabled should prioritize this update.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Check installed kernel version: uname -r | grep -E '^5\.17\.[0-1]' (vulnerable if output matches)
  2. Verify CXL support is enabled: grep -i cxl /boot/config-$(uname -r) (look for CONFIG_CXL=y or CONFIG_CXL=m)
  3. Search system logs for KASAN errors: dmesg | grep -i 'use-after-free\|cxl_decoder_release' or journalctl -xe | grep -i 'use-after-free'
  4. After patching, confirm updated version: uname -r (should show 5.17.2 or later)

FAQ

What is CVE-2022-49223?

A use-after-free vulnerability in the Linux kernel's CXL (Compute Express Link) decoder subsystem where the parent port object is accessed after being freed, potentially causing kernel memory corruption and system instability.

Is CVE-2022-49223 being actively exploited?

No, this vulnerability is not currently being actively exploited and is not listed in CISA's Known Exploited Vulnerabilities catalog.

What versions of Kernel are affected by CVE-2022-49223?

Linux kernel versions 5.17.0 through 5.17.1 are vulnerable; version 5.17.2 and later contain the fix.

How do I check if my server is vulnerable to CVE-2022-49223?

Run `uname -r` and check if output matches 5.17.[0-1]; then verify CXL support is enabled with `grep CONFIG_CXL /boot/config-$(uname -r)` (must show y or m).

Does Defensia detect CVE-2022-49223?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2022-49223 will appear in your dashboard with remediation steps.

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References

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