What happened
In the Linux kernel, the following vulnerability has been resolved: coresight: perf: Retrieve path and source from event data ETM perf callbacks currently use the per-CPU csdev_src pointer, which can race with updates during device registration and unregistration. The AUX setup already builds and stores the path in the event data. Use this path to retrieve the source instead of csdev_src to avoid the race. Export coresight_get_source() and add etm_event_get_ctxt_path() to retrieve the context's path and its source with READ_ONCE() / WRITE_ONCE() accessors. Give the comments to explain why this approach is safe when pause or resume callbacks preempt the disable callback (e.g. via NMI).
Affected versions
Linux: 0bcbf2e30ff2271b54f54c8697a185f7d86ec6e4 through before 0f4cb08f30011b7625a4fba668fa5c36da5e6637 (git); 0bcbf2e30ff2271b54f54c8697a185f7d86ec6e4 through before f37bc31447c0ddafedb25e3c4a4f4e2284034247 (git); 4.6 Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.
Public PoC references
No public PoC reference has passed the current publication threshold.