CVE-2022-1734 Overview
A use-after-free vulnerability exists in the Linux Kernel within the nfcmrvl_nci_unregister_dev() function located in drivers/nfc/nfcmrvl/main.c. This flaw occurs due to improper synchronization between the cleanup routine and the firmware download routine, potentially allowing both read and write operations on freed memory.
Critical Impact
Local attackers with low privileges can exploit this use-after-free condition to achieve arbitrary code execution, escalate privileges, or cause system instability through memory corruption.
Affected Products
- Linux Kernel (versions prior to 5.18 and release candidates 5.18-rc1 through 5.18-rc5)
- Debian Linux 9.0 and 10.0
- NetApp H300S, H500S, H700S, H300E, H500E, H700E, H410S, and H410C (firmware)
Discovery Timeline
- May 18, 2022 - CVE-2022-1734 published to NVD
- November 21, 2024 - Last updated in NVD database
Technical Details for CVE-2022-1734
Vulnerability Analysis
This use-after-free vulnerability stems from a race condition in the NFC Marvell driver's device unregistration process. When the nfcmrvl_nci_unregister_dev() function is called, destructive operations are performed in an order that creates a window where the firmware download routine can access memory that has already been freed.
The vulnerability is particularly concerning because it affects the NFC subsystem, which handles Near Field Communication operations. The race condition arises when a device cleanup occurs while firmware download is still in progress, leading to potential access of deallocated memory structures.
Successful exploitation requires local access and the ability to trigger the race condition between the cleanup and firmware download routines. An attacker could leverage this vulnerability to execute arbitrary code in kernel context, escalate privileges, or cause denial of service through kernel panic.
Root Cause
The root cause of CVE-2022-1734 is improper ordering of destructive operations in the nfcmrvl_nci_unregister_dev() function. Specifically, the code failed to unregister the NCI device before checking and aborting any ongoing firmware download operations. This ordering allowed a race condition where the firmware download routine could continue accessing device structures after they had been partially cleaned up, resulting in use-after-free conditions.
Attack Vector
The attack vector for CVE-2022-1734 is local, requiring an attacker to have local access to a system running a vulnerable Linux kernel with the NFC Marvell driver loaded. The attacker must be able to trigger the race condition between device unregistration and firmware download. This could be achieved by:
- Initiating an NFC firmware download operation
- Simultaneously triggering device unregistration or removal
- Exploiting the timing window to access freed memory structures
The fix reorders the operations to ensure nci_unregister_device() is called before checking firmware download status:
{
struct nci_dev *ndev = priv->ndev;
+ nci_unregister_device(ndev);
if (priv->ndev->nfc_dev->fw_download_in_progress)
nfcmrvl_fw_dnld_abort(priv);
Source: GitHub Linux Commit Change
Detection Methods for CVE-2022-1734
Indicators of Compromise
- Unexpected kernel panics or oops messages referencing nfcmrvl or NFC-related functions
- Memory corruption errors in kernel logs related to the NFC subsystem
- Suspicious process activity attempting to interact with NFC devices during system changes
- Kernel crash dumps showing use-after-free in drivers/nfc/nfcmrvl/ code paths
Detection Strategies
- Monitor kernel logs for use-after-free warnings or errors related to the nfcmrvl driver module
- Implement kernel runtime detection mechanisms such as KASAN (Kernel Address Sanitizer) to detect memory access violations
- Deploy endpoint detection solutions capable of monitoring kernel-level memory operations and anomalies
- Track NFC device registration and unregistration events for unusual timing patterns
Monitoring Recommendations
- Enable kernel auditing for NFC subsystem operations and device state changes
- Implement system integrity monitoring to detect unauthorized kernel module loading or manipulation
- Configure alerts for kernel crash events specifically related to NFC drivers
- Monitor for privilege escalation attempts following NFC-related system activity
How to Mitigate CVE-2022-1734
Immediate Actions Required
- Update the Linux kernel to a patched version that includes commit d270453a0d9ec10bb8a802a142fb1b3601a83098
- Apply vendor-specific patches from Debian (DSA-5173) or NetApp security advisories as applicable
- If immediate patching is not possible, consider blacklisting the nfcmrvl kernel module if NFC functionality is not required
- Monitor systems for signs of exploitation while patching is in progress
Patch Information
The vulnerability has been addressed in the upstream Linux kernel through commit d270453a0d9ec10bb8a802a142fb1b3601a83098, which reorders destructive operations in nfcmrvl_nci_unregister_dev() to ensure proper synchronization. The fix ensures that nci_unregister_device() is called before checking the firmware download status, eliminating the race condition.
Downstream distributions have released their own patches:
Workarounds
- Blacklist the nfcmrvl kernel module to prevent it from loading if NFC functionality is not required
- Restrict local access to trusted users only to limit the attack surface
- Implement mandatory access control policies (SELinux/AppArmor) to restrict NFC device access
- Disable NFC hardware at the BIOS/UEFI level if the functionality is not needed
# Blacklist nfcmrvl module to prevent loading
echo "blacklist nfcmrvl" >> /etc/modprobe.d/blacklist-nfc.conf
echo "install nfcmrvl /bin/false" >> /etc/modprobe.d/blacklist-nfc.conf
# Unload module if currently loaded
modprobe -r nfcmrvl
# Update initramfs to persist changes across reboots
update-initramfs -u
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
