CVE-2022-1652 Overview
CVE-2022-1652 is a use-after-free vulnerability [CWE-416] in the Linux kernel floppy driver. The flaw resides in the bad_flp_intr function, where a concurrency error allows freed memory to be referenced during interrupt handling. A local attacker with low privileges can trigger the race condition by executing a specially crafted program. Successful exploitation enables arbitrary code execution in kernel context or causes a denial of service through system crash. The vulnerability affects the upstream Linux kernel, Red Hat Enterprise Linux 9.0, Debian 10, and several NetApp HCI storage products that ship Linux-based firmware.
Critical Impact
Local low-privileged attackers can achieve kernel-level arbitrary code execution, leading to full system compromise on affected Linux distributions.
Affected Products
- Linux Kernel (multiple versions)
- Red Hat Enterprise Linux 9.0 and Debian Linux 10
- NetApp H300S, H410C, H410S, H500S, and H700S HCI storage systems
Discovery Timeline
- 2022-06-02 - CVE-2022-1652 published to NVD
- 2024-11-21 - Last updated in NVD database
Technical Details for CVE-2022-1652
Vulnerability Analysis
The vulnerability is a concurrency use-after-free in the Linux kernel floppy disk driver. The bad_flp_intr function handles error conditions during floppy interrupt processing. Under specific timing conditions, one execution path frees a kernel object while another path continues to reference it.
The issue is classified as CWE-416 (Use After Free). Because the flaw exists in kernel code, successful exploitation grants attackers the highest level of system access. The attack requires local access and low privileges, but no user interaction is needed once the attacker has shell access.
The EPSS score is 0.748%, indicating limited but non-trivial likelihood of exploitation activity. No public proof-of-concept exploit has been published, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.
Root Cause
The root cause is improper synchronization between concurrent code paths in the floppy driver. When bad_flp_intr executes, the underlying request structure can be freed by a parallel context before the interrupt handler completes its use of the object. The absence of proper locking or reference counting around the shared object permits the dangling pointer dereference.
Attack Vector
An attacker requires local shell access with low privileges on the target system. The attacker executes a crafted program that interacts with the floppy device subsystem to race the kernel paths that access and free the request object. Winning the race produces memory corruption that can be shaped into arbitrary kernel code execution or a kernel panic. Systems without the floppy driver loaded are not exposed.
No verified public exploit code is available. Refer to the Red Hat Bug Report #1832397 and CERT Vulnerability ID #647177 for additional technical context.
Detection Methods for CVE-2022-1652
Indicators of Compromise
- Unexpected kernel oops or panic messages referencing bad_flp_intr or the floppy driver in dmesg and /var/log/messages.
- Unprivileged user processes loading or interacting with the floppy kernel module on systems where floppy access is not expected.
- Anomalous ioctl or open syscalls targeting /dev/fd* devices from non-administrative accounts.
Detection Strategies
- Audit running kernel versions against vendor advisories and flag hosts running unpatched releases identified by Debian Security Advisory DSA-5173 and NetApp Security Advisory NTAP-20220722-0002.
- Monitor for runtime loading of the floppy module via modprobe or insmod on production servers that have no operational need for it.
- Correlate kernel crash dumps containing use-after-free signatures in floppy driver code paths with recent process execution by non-root users.
Monitoring Recommendations
- Enable auditd rules covering init_module, finit_module, and delete_module syscalls to track kernel module activity.
- Aggregate kernel ring buffer events centrally and alert on KASAN or general protection fault entries referencing block or floppy subsystems.
- Track outcomes of vulnerability scans against the affected CPE list to confirm patch deployment coverage.
How to Mitigate CVE-2022-1652
Immediate Actions Required
- Apply the kernel updates published by your distribution, including the fix referenced in Debian Security Advisory DSA-5173 for Debian 10 systems.
- Update NetApp HCI storage nodes per NetApp Security Advisory NTAP-20220722-0002.
- Reboot patched systems to ensure the updated kernel image is active.
Patch Information
Upstream Linux kernel maintainers addressed the concurrency flaw in the floppy driver. Red Hat, Debian, and NetApp have shipped fixed kernel packages and firmware for affected products. Confirm remediation by validating the running kernel version against the fixed releases listed in the vendor advisories.
Workarounds
- Blacklist the floppy kernel module on systems that do not require floppy device support by adding blacklist floppy to /etc/modprobe.d/blacklist.conf.
- Restrict access to /dev/fd* device nodes through restrictive permissions and Linux capability controls.
- Limit local shell access on multi-tenant systems to reduce the population of users able to attempt the local race condition.
# Configuration example: prevent the floppy driver from loading
echo "blacklist floppy" | sudo tee /etc/modprobe.d/disable-floppy.conf
echo "install floppy /bin/true" | sudo tee -a /etc/modprobe.d/disable-floppy.conf
sudo rmmod floppy 2>/dev/null || true
sudo update-initramfs -u
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
