A new vulnerability, called CVE-2022-1734, has been discovered in the Linux Kernel's NFC (near-field communication) driver, specifically in the nfcmrvl_nci_unregister_dev() function. This vulnerability can lead to use-after-free issues, resulting in potential security issues such as unauthorized data access, information leakage, denial of service (DoS), and potentially even remote code execution.

In simple terms, the "Use-After-Free" vulnerability happens when the memory allocation is freed, while still being used by other parts of the code. This flaw exposes the system to hackers, who can manipulate and exploit this memory allocation to gain unauthorized access or even take control of the affected system.

Affected Versions

This vulnerability affects the Linux Kernel 4.19 and later versions. It resides in the nfcmrvl_nci_unregister_dev() function located in the drivers/nfc/nfcmrvl/main.c file.

Vulnerability Details

The vulnerability exists due to a non-synchronization issue between the cleanup routine and firmware download routine in the nfcmrvl_nci_unregister_dev() function. The cleanup routine releases the memory allocated for the NFC device, while the firmware download routine accesses the same memory, resulting in a use-after-free error.

The specific code snippet concerning this vulnerability is shown below

void nfcmrvl_nci_unregister_dev(struct nfcmrvl_private *priv)
{
    struct nci_dev *ndev = priv->ndev;

    if (ndev) {
        nci_unregister_device(ndev);
        nci_free_device(ndev);
        priv->ndev = NULL;
    }
}

Schedule the firmware download routine to occur in parallel.

3. Successfully exploit the use-after-free issue during the non-synchronized execution of both routines, potentially causing a crash, information leakage, or even remote code execution.

Original References

- The Linux Kernel repository: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
- The specific file containing the vulnerability: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/nfc/nfcmrvl/main.c
- The CVE-2022-1734 vulnerability report: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-1734
- The National Vulnerability Database (NVD) record: https://nvd.nist.gov/vuln/detail/CVE-2022-1734

Mitigation

To mitigate this vulnerability, it is recommended to apply patches provided by the Linux Kernel maintainers once they are available. System administrators should also restrict access to the NFC driver, monitor any suspicious activity, and keep their systems up-to-date with the latest security patches. Developers should ensure proper synchronization is enforced between the cleanup routine and firmware download routine, thus eliminating the use-after-free issue.

Conclusion

CVE-2022-1734 is a critical use-after-free vulnerability in the Linux Kernel's NFC driver module and can lead to severe consequences if exploited by an attacker. It is crucial to stay informed, apply the necessary patches, and ensure secure programming practices are followed to mitigate this vulnerability and maintain a secure system.

Timeline

Published on: 05/18/2022 17:15:00 UTC
Last modified on: 07/07/2022 15:15:00 UTC