CVE-2023-52787

What it actually does

A race condition in blk-mq allows blk_integrity_unregister to execute while a bio with integrity data prepared lacks a held queue usage counter, causing the request to complete and invoke profile->complete_fn leading to kernel panic; bio_integrity_prep must also occur before bio merge.

Why it matters to the business

Affected Linux kernel deployments may experience sudden system crashes during storage I/O, resulting in downtime, potential data loss, and service disruption across servers and devices with high ecosystem prevalence.

How an attack unfolds

An attacker issues concurrent bio operations with integrity preparation while triggering queue unregistration to hit the race; associated with Android Kernel Remote Code Execution Vulnerability threat actors attempting to induce panic or instability.

How to fix it

Upgrade the Linux kernel in org/pub/scm/linux/kernel/git/stable/linux.git to the fixed commit b5c8e0ff76d10f6bf70a7237678f27c20cf59bc9 ensuring bio_integrity_prep holds the queue usage counter and executes before bio merge.

How to confirm the fix worked

Confirm the presence of the fix commit b5c8e0ff76d10f6bf70a7237678f27c20cf59bc9 in the kernel source tree and verify bio_integrity_prep calls are protected by queue usage counters in blk-mq.

Typical attack path

1. Locate systems running vulnerable Linux kernel versions prior to the fix commit
2. Issue crafted I/O requests that prepare bio integrity data
3. Concurrently invoke blk_integrity_unregister on the queue
4. Force request completion to trigger the unprotected complete_fn call and panic

How to detect it

Inspect kernel logs and crash dumps for oops or panic messages referencing blk_integrity_unregister, bio_integrity_prep, or queue usage counters; correlate with I/O heavy workloads.

What your security team should do

• Apply the kernel update to b5c8e0ff76d10f6bf70a7237678f27c20cf59bc9 immediately on all affected systems given the 877 days since publication
• Review and test storage I/O paths in non-production environments before rollout
• Monitor kernel logs for panic signatures involving bio integrity after patching