CVE-2022-48963

What it actually does

Failure to release ipc_mux after unsuccessful allocation of ipc_mux->ul_adb.pp_qlt in ipc_mux_init() leaves kernel memory allocated.

Why it matters to the business

Repeated trigger conditions can gradually exhaust kernel memory, leading to degraded performance or denial of service on systems using the affected WWAN driver.

How an attack unfolds

An attacker triggers the error path in ipc_mux_init by causing the allocation of ul_adb.pp_qlt to fail, resulting in the ipc_mux structure never being freed and accumulating unreleased memory.

How to fix it

Apply the kernel fix that ensures ipc_mux is released on allocation failure; for tukaani-project/xz (GIT) update to commit bf518b9ba446327a062ddfe67e7e0a5baed2394f.

How to confirm the fix worked

Confirm the corrected error-handling path is present in ipc_mux_init and test allocation-failure scenarios to verify no leak occurs.

Typical attack path

1. Identify systems exposing the iosm WWAN driver
2. Induce resource pressure or specific device initialization sequences that cause the allocation to fail
3. Repeat to accumulate leaked memory until system impact occurs

How to detect it

Review kernel logs for repeated ipc_mux_init failures; inspect memory leak detectors or slabinfo for unreleased ipc_mux objects after driver initialization attempts.

What your security team should do

• Prioritize patching kernel packages containing the iosm driver on all affected systems
• Monitor memory usage on devices using WWAN iosm functionality
• Apply the referenced commit or backported equivalent immediately due to public disclosure