Kernel hang via non-atomic CSD lock acquisition
Published Aug 12, 2026 · Updated Aug 12, 2026
Race condition in Linux kernel 7.1 through 7.1.5 allows local users to hang the system through concurrent CSD callbacks. In csd_lock(), separate wait and set operations perform a non-atomic read-modify-write on CSD_FLAG_LOCK, so competing CPUs overwrite callback fields and can enqueue the same llist node twice. The race exists only when CSD lock debugging is enabled and async no-wait calls share destination-CPU CSD data; a self-linked queue can stall later synchronous work and produce soft lockups or kernel panics.
Summary
What happened
Race condition in Linux kernel 7.1 through 7.1.5 allows local users to hang the system through concurrent CSD callbacks. In csd_lock(), separate wait and set operations perform a non-atomic read-modify-write on CSD_FLAG_LOCK, so competing CPUs overwrite callback fields and can enqueue the same llist node twice. The race exists only when CSD lock debugging is enabled and async no-wait calls share destination-CPU CSD data; a self-linked queue can stall later synchronous work and produce soft lockups or kernel panics.
The record
- CVE
- CVE-2026-68438
- Published
- Aug 12, 2026
- Updated
- Aug 12, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-821, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 12, 2026CVE publishedPublication date reported by the CVE source.
- Aug 12, 2026Record updatedLatest update available in the CVE record.
Exploitability
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- Affected versionversion=7.1
- Affected versionversion=b0473dcd4b1d7e2e44947e7ac1820c73a268821a <282d220bae5fbfc90cf0e3d5b5e42c00ad79f989
- Affected versionversion=b0473dcd4b1d7e2e44947e7ac1820c73a268821a <35551efb155e3b83445a6c3f66cb498d5efc182c
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