From: Steven Rostedt <[email protected]>
Sashiko reported that the code was using meta->nr_subbufs without making
sure that it matched the nr_pages + 1 on data that was assuming the two
were the same.
Add a check to the persistent ring buffer validation code to make sure
that the saved nr_subbufs matches what we expect.
Fixes: f5b95f1fa2ef3 ("ring-buffer: Validate the persistent meta data subbuf
array")
Reported-by: [email protected]
Closes: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Steven Rostedt <[email protected]>
---
kernel/trace/ring_buffer.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index ef66f726e2e2..748d4ae8badf 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1869,6 +1869,11 @@ static bool rb_cpu_meta_valid(struct
ring_buffer_cpu_meta *meta, int cpu,
return false;
}
+ if (meta->nr_subbufs != nr_pages + 1) {
+ pr_info("Ring buffer boot meta [%d] invalid nr_subbufs\n", cpu);
+ return false;
+ }
+
buffers_start = meta->first_buffer;
buffers_end = meta->first_buffer + (subbuf_size * meta->nr_subbufs);
--
2.53.0
