CVE-2024-53140

What it actually does

Race condition in netlink dump handling allows improper cleanup of socket state during close from process context versus BH context, leading to use-after-free or reference count mishandling on the netlink socket.

Why it matters to the business

Local users on affected Linux systems can trigger kernel crashes or hangs via netlink sockets, causing denial of service and potential system reboots; low exploitation likelihood but widespread impact on kernels using netlink for configuration and monitoring.

How an attack unfolds

An attacker with local access opens a netlink socket, initiates an iterative dump via recvmsg calls, then closes the socket before the dump completes. The flawed workqueue deferral fails to guarantee last-reference ownership, allowing a race where async code or BH release leads to invalid socket access or memory corruption.

How to fix it

Update the Linux kernel to a version containing commit 69973b830859bc6529a7a0468ba0d80ee5117826 or later; rebuild and deploy updated kernel packages across all affected systems. Reboot after upgrade and verify netlink functionality.

How to confirm the fix worked

Confirm kernel version includes the referenced commit via uname or git describe; test netlink socket close during active dumps with tools like ss or custom reproducers; monitor for absence of crashes in dmesg related to netlink release.

Typical attack path

1. Obtain local code execution or shell on target Linux system
2. Open netlink socket and start iterative data dump operation
3. Close socket before dump finishes to trigger release handler
4. Trigger race via concurrent BH or reference release to exploit cleanup flaw
5. Cause kernel panic, hang, or memory corruption for denial of service

How to detect it

Review kernel logs for netlink-related oops or warnings during socket close; inspect audit logs or strace output for processes performing netlink dumps followed by immediate closes; correlate with any unexplained system reboots on Linux hosts.

What your security team should do

• Prioritize kernel upgrades on all production Linux hosts within standard patch cycles given low EPSS and no KEV status
• Audit systems for heavy netlink usage in monitoring or configuration tools and schedule targeted testing
• Enable kernel panic logging and watchdog mechanisms to detect exploitation attempts quickly
• Review downstream package ecosystems for delayed updates and coordinate with vendors on backports