CVE-2023-54030

What it actually does

The vulnerability allows multishot recv operations in io_uring to generate an unbounded number of completion queue events (CQEs), leading to excessive memory consumption that can exhaust resources and trigger an out-of-memory condition for the affected task.

Why it matters to the business

Systems relying on io_uring for high-volume network receive operations may experience degraded performance or unexpected process termination due to memory exhaustion, potentially disrupting services that depend on the Linux kernel networking stack.

How an attack unfolds

An attacker triggers repeated multishot recv requests via io_uring on a network socket under their control, causing the kernel to queue an ever-growing number of CQEs without bounds; in the worst case this leads to resource exhaustion without requiring elevated privileges.

How to fix it

Upgrade affected Linux kernel installations to a version containing commit 1e2db9837be7d24a2a74eb3f3906d0872bee8907. For amazon-ssm-agent-fips (Chainguard) update to version 3.3.2656.0-r1 or later. Rebuild and redeploy any custom kernels or distributions incorporating the fix.

How to confirm the fix worked

Verify the running kernel contains commit 1e2db9837be7d24a2a74eb3f3906d0872bee8907 by inspecting /proc/version or kernel build logs; test io_uring multishot recv workloads under load to confirm CQE counts remain bounded.

Typical attack path

1. Establish a network connection to a target system using io_uring-enabled applications
2. Submit multishot recv requests through the io_uring interface
3. Continue sending or withholding data to force repeated CQE generation
4. Observe or induce memory pressure until the target task is OOM-killed

How to detect it

Review kernel logs for OOM killer invocations involving processes using io_uring; inspect audit or system call logs for high volumes of io_uring recv operations; correlate with unusual memory growth in network-handling tasks.

What your security team should do

• Prioritize kernel upgrades on systems exposing io_uring network workloads
• Monitor EPSS and KEV status for any future changes indicating increased exploitability
• Audit applications using io_uring recv operations for safe usage patterns
• Apply the fixed versions listed for each affected package