CVE-2024-50207: ring-buffer: Fix reader locking when changing the sub buffer order

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-11-08 · updated 2026-08-04
Weakness: CWE-667

Description

In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Fix reader locking when changing the sub buffer order The function ring_buffer_subbuf_order_set() updates each ring_buffer_per_cpu and installs new sub buffers that match the requested page order. This operation may be invoked concurrently with readers that rely on some of the modified data, such as the head bit (RB_PAGE_HEAD), or the ring_buffer_per_cpu.pages and reader_page pointers. However, no exclusive access is acquired by ring_buffer_subbuf_order_set(). Modifying the mentioned data while a reader also operates on them can then result in incorrect memory access and various crashes. Fix the problem by taking the reader_lock when updating a specific ring_buffer_per_cpu in ring_buffer_subbuf_order_set().

Affected products

Linux kernel: from 6.8 before 6.11.6; 6.12-rc1, 6.12-rc2, 6.12-rc3 — fixed in 6.11.6

How to fix

Upgrade to a fixed version: Linux kernel 6.11.6. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2024-50207 or the next vulnerability affects your stack