CVE-2023-52926

What it actually does

The flaw causes IORING_OP_READ to skip consuming the provided buffer list on read I/O errors (except -EAGAIN and -EIOCBQUEUED), allowing a use-after-free when io_rw_done completes in a separate context.

Why it matters to the business

Systems running affected Linux kernels risk memory corruption that can lead to crashes, data integrity issues, or potential privilege escalation; the low EPSS and lack of KEV listing indicate limited observed exploitation despite the 614-day exposure window and related kernel privilege-escalation activity in the ecosystem.

How an attack unfolds

An attacker issues an io_uring read operation that returns a negative error code other than the exempted values, leaving the buffer list unconsumed; subsequent completion processing in io_rw_done then accesses the freed buffer, enabling use-after-free exploitation for memory corruption or code execution.

How to fix it

Upgrade the Linux kernel to the fixed commit 72060434a14caea20925e492310d6e680e3f9007 or later stable releases; for neutron packages update to 7.1.0 or 8.1.0.

How to confirm the fix worked

Verify the running kernel contains commit 72060434a14caea20925e492310d6e680e3f9007 via git log or uname; confirm neutron version is 7.1.0+ or 8.1.0+; test io_uring read error paths to ensure buffer lists are properly consumed.

Typical attack path

1. Craft and submit an io_uring read request designed to trigger an error return < 0
2. Force the error path that bypasses buffer-list consumption
3. Trigger io_rw_done in a separate context to dereference the stale buffer
4. Leverage the resulting use-after-free for memory corruption or privilege escalation

How to detect it

Review kernel logs and audit trails for io_uring error paths involving read operations; correlate with process crashes or unexpected memory faults around io_rw_done; no specific threat-actor campaigns tied to this CVE have been observed.

What your security team should do

• Prioritize kernel upgrades on all systems using io_uring within the next patching cycle
• Audit applications for io_uring usage and restrict untrusted access where possible
• Monitor for related Linux kernel privilege-escalation activity listed under similar CVEs