CVE-2023-1032

What it actually does

Double free vulnerability in the Linux kernel's __sys_socket_file() function triggered by the io_uring IORING_OP_SOCKET operation, resulting in memory corruption that can cause kernel crashes or denial of service.

Why it matters to the business

Linux systems using io_uring for high-performance I/O may experience unexpected crashes or service disruptions, increasing downtime and operational costs especially in environments with high kernel dependency counts.

How an attack unfolds

An attacker with local access crafts a malicious io_uring submission queue entry using the IORING_OP_SOCKET operation to trigger the double free path in net/socket.c, potentially leading to kernel instability or exploitation attempts for further impact.

How to fix it

Update the Linux kernel to a version containing commit 457391b0380335d5e9a5babdec90ac53928b23b4 or later; apply the fix from the stable branches that include this change.

How to confirm the fix worked

Verify the running kernel includes commit 457391b0380335d5e9a5babdec90ac53928b23b4 by checking git log or kernel version strings; test io_uring socket operations under load to confirm stability.

Typical attack path

1. Obtain local user access on a vulnerable Linux system
2. Prepare an io_uring instance and submit an IORING_OP_SOCKET request designed to hit the double free condition
3. Trigger the operation to cause memory corruption and kernel panic
4. Attempt to leverage resulting instability for privilege escalation or denial of service

How to detect it

Search system logs for kernel oops, panic messages, or double free warnings involving socket or io_uring functions; examine audit logs for unusual io_uring activity from local processes.

What your security team should do

• Prioritize kernel updates on systems using io_uring in production within the next maintenance window
• Monitor for kernel oops or panic logs related to socket operations
• Restrict untrusted local access where possible until patched
• Review io_uring usage in applications and consider fallback mechanisms if updates are delayed