CVE-2023-54225

What it actually does

Reference count underflow on IPA GSI channel transactions during modem shutdown cleanup when hashing is unsupported, caused by allocating and committing transactions to zero hashed filter and routing tables that should not be touched.

Why it matters to the business

Kernel instability or crashes on affected Linux systems using IPA hardware during modem power-down sequences, increasing downtime risk on mobile and embedded devices; low exploitation probability limits widespread impact.

How an attack unfolds

An attacker with local access or the ability to trigger modem shutdown (such as through power management or error conditions) causes unused transactions to be committed when ipa_filter_reset_table and routing table zeroing attempt hashed table ranges on unsupported hardware, resulting in reference count underflow that can lead to memory corruption.

How to fix it

Update to Linux kernel commit 50c24f0c940728792c8bdf65c1eaf6b91b3b0dcd or later stable releases that skip hashed table resets when hashing is unsupported.

How to confirm the fix worked

Verify kernel source contains the fix preventing hashed table access in ipa_filter_reset_table and ipa_routing_reset_table; test modem shutdown paths for absence of transaction underflow warnings.

Typical attack path

1. Trigger modem shutdown sequence on IPA-enabled device
2. ipa_filter_reset_table allocates transaction for hashed table zeroing despite lack of hashing support
3. Unused transaction is committed, decrementing reference count below zero
4. Underflow leads to corrupted transaction state and potential kernel memory issues

How to detect it

Review kernel logs and dmesg output around modem shutdown events for reference count underflow messages or transaction allocation anomalies in the IPA driver.

What your security team should do

• Apply the referenced kernel commit or newer stable version immediately on all IPA-equipped systems
• Monitor kernel logs for transaction reference count warnings during shutdown
• Prioritize updates on devices with frequent modem power cycles