CVE-2025-38063: dm: fix unconditional IO throttle caused by REQ_PREFLUSH
dm: fix unconditional IO throttle caused by REQPREFLUSH
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.6.96.1-1 - Upgrade
Upgrade
Linux kernel (dm/xfs)to a version that resolves this vulnerability.Patch 2def2845cc33 - Configuration
Apply the kernel fix that conditionally adds REQ_IDLE to flush_bio.bi_opf, and ensures wbt_should_throttle() returns false for the metadata flush_bio generated from REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC, so wbt_wait() does not throttle it.
Linux kernel block I/O (wbt_should_throttle / flush_bio throttling) REQ_IDLE added to flush_bio.bi_opf when flushing metadata = conditionally add REQ_IDLE to flush_bio.bi_opf for REQ_PREFLUSH flush_bio
Event History
Frequently Asked Questions
What is the severity of CVE-2025-38063?
CVE-2025-38063 has been assigned a medium severity level due to its potential impact on IO operations in the Linux kernel.
How do I fix CVE-2025-38063?
To fix CVE-2025-38063, update your Linux kernel to the latest version that addresses the vulnerability.
Which versions of the Linux Kernel are affected by CVE-2025-38063?
CVE-2025-38063 affects Linux Kernel versions starting from 5.4.
What are the consequences of exploiting CVE-2025-38063?
Exploiting CVE-2025-38063 can lead to unintended I/O throttling, affecting system performance.
Is there a workaround for CVE-2025-38063 until I can update?
There is no recommended workaround for CVE-2025-38063; updating the kernel is the best mitigation.