Executive brief
A race condition was identified in the Linux kernel's CoreSight subsystem, which is used for hardware tracing and debugging. When two different tracing modes (sysfs and perf) are used at the same time, the system may encounter internal errors or instability. This could potentially lead to a system crash or denial of service for debugging tools.
Technical details
A race condition exists in the CoreSight TMC-ETR (Trace Memory Controller - Embedded Trace Router) driver due to the separation of sysfs mode enablement into two distinct critical regions: buffer allocation and hardware enablement. If a 'perf' mode session is initiated between these two regions, the 'drvdata->etr_buf' may be initialized by the perf side, causing a WARN_ON() trigger and potential state corruption when the sysfs side subsequently attempts hardware enablement. The fix introduces a double-check for CS_MODE_PERF within the spinlock-protected region of 'tmc_enable_etr_sink_sysfs' to ensure the hardware is not already in use by perf before proceeding.
Affected products
- Linux Linux Kernel Fixed in 38a0719, 6906aa7, e6e43e8
Timeline
- 2026-01-21: patched: Initial patch submitted by Yicong Yang
- 2026-06-03: advisory: CVE-2026-46272 published by kernel.org and NVD