[PATCH v2 0/2] tracing: Fix buffer_meta open paths

[David Carlier <devnexen@gmail.com>]

Two fixes for per_cpu/cpuN/buffer_meta open. The first drops the
trace_array reference under trace_types_lock on the error path. The
second fails the open for CPUs that never came online, which would
otherwise dereference a NULL cpu_buffer on read. With the second patch,
that error path becomes reachable in practice.

Changes since v1:
- Add patch 2 for the NULL dereference Sashiko reported on v1.

v1: https://lore.kernel.org/all/20260913133829.15307-1-devnexen@gmail.com/

David Carlier (2):
  tracing: Take trace_types_lock when dropping the buffer_meta reference
  ring-buffer: Do not show buffer_meta for CPUs without a buffer

 kernel/trace/ring_buffer.c | 3 +++
 kernel/trace/trace.c       | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

-- 
2.55.0