CVE-2024-50207

What it actually does

Concurrent modification of ring_buffer_per_cpu structures (head bit, pages, reader_page) without acquiring reader_lock during subbuf order changes leads to invalid memory accesses and crashes.

Why it matters to the business

System instability and crashes on affected Linux kernels can disrupt operations and availability, especially in environments with high ring-buffer usage; the listed packages indicate legacy Ubuntu deployments require urgent updates.

How an attack unfolds

An attacker with local access triggers ring_buffer_subbuf_order_set() concurrently with active readers that rely on unmodified pointers and flags, resulting in crashes; listed threat actor campaigns highlight ongoing kernel race condition exploitation attempts by espionage and financially motivated groups.

How to fix it

Apply kernel patches that acquire reader_lock during ring_buffer_subbuf_order_set() updates; for the listed packages upgrade chromium-browser to 47.0.2526.73-0ubuntu0.14.04.1.1106 and oxide-qt to 1.11.3-0ubuntu0.14.04.1 on Ubuntu 14.04 LTS.

How to confirm the fix worked

Confirm kernel source includes the reader_lock acquisition around per-CPU updates in ring_buffer_subbuf_order_set(); test by exercising concurrent subbuf order changes and reader operations without crashes.

Typical attack path

1. Obtain local access or trigger ring buffer sub-buffer order change
2. Race reader operations against the unlocked update in ring_buffer_subbuf_order_set()
3. Cause invalid memory access leading to kernel panic or crash

How to detect it

Review kernel logs and crash dumps for ring_buffer_subbuf_order_set related faults or use-after-free patterns in ring buffer code; correlate with process activity that modifies sub-buffer order while readers are active.

What your security team should do

• Prioritize patching affected kernels and listed packages before the CISA-adjacent deadlines if applicable
• Monitor for kernel crashes involving ring buffer structures
• Limit unprivileged local access where ring buffer resizing is possible