tracing: Have process_string() also allow arrays

Summary

In the Linux kernel, the following vulnerability has been resolved: tracing: Have process_string() also allow arrays In order to catch a common bug where a TRACE_EVENT() TP_fast_assign() assigns an address of an allocated string to the ring buffer and then references it in TP_printk(), which can be executed hours later when the string is free, the function test_event_printk() runs on all events as they are registered to make sure there's no unwanted dereferencing. It calls process_string() to handle cases in TP_printk() format that has "%s". It returns whether or not the string is safe. But it can have some false positives. For instance, xe_bo_move() has: TP_printk("move_lacks_source:%s, migrate object %p [size %zu] from %s to %s device_id:%s", __entry->move_lacks_source ? "yes" : "no", entry->bo, entry->size, xe_mem_type_to_name[__entry->old_placement], xe_mem_type_to_name[__entry->new_placement], __get_str(device_id)) Where the "%s" references into xe_mem_type_to_name[]. This is an array of pointers that should be safe for the event to access. Instead of flagging this as a bad reference, if a reference points to an array, where the record field is the index, consider it safe.

Timeline

1. Jan 21, 2025, 12:01 PM UTCCVE published
2. May 11, 2026, 9:00 PM UTCRecord last updated

Affected versions

• Linux Linux

  Version range not reported

• Linux Linux

  From 6.1.122 · fixed in 6.1.124; From 6.6.68 · fixed in 6.6.70; From 6.12.7 · fixed in 6.12.9

References 5