From 6d014e44b68ddd43f71288d2a4dbb1a259869149 Mon Sep 17 00:00:00 2001 From: Vincent Donnefort Date: Thu, 6 Aug 2026 22:13:03 +0100 Subject: [PATCH] ring-buffer: Initialise reader page order in rb_allocate_cpu_buffer() In rb_allocate_cpu_buffer(), bpage->order was omitted, leaving it as 0. This is an issue for a ring-buffer with subbufs bigger than PAGE_SIZE if when freed: free_buffer_page() relies on this value. Align the value with the actual allocation size (buffer::subbuf_order). Cc: stable@vger.kernel.org Fixes: f9b94daa542a ("ring-buffer: Set new size of the ring buffer sub page") Link: https://patch.msgid.link/20260806211306.3704194-4-vdonnefort@google.com Signed-off-by: Vincent Donnefort Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 6cbd80ccef37..760a00e8505c 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2510,6 +2510,7 @@ rb_allocate_cpu_buffer(struct trace_buffer *buffer, long nr_pages, int cpu) bpage = alloc_cpu_page(cpu); if (!bpage) return NULL; + bpage->order = cpu_buffer->buffer->subbuf_order; rb_check_bpage(cpu_buffer, bpage); -- 2.47.3