From nobody Sat Sep 26 07:15:49 2026 Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2D1A64F55D3; Thu, 3 Sep 2026 17:26:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.13 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788456395; cv=none; b=DVDL7DtfRhT2CUi9aPxVwIX704oELyyp3suivSF2apGlt+9E7EjN+a4jH8qV1EbQ8uxOw2d2sc1qj5F0RGPoJdrt65eXQ5qXzCX2QqiM0O8B78QxdO0MNRCQlPSdQfkA5zEJbBdZSZirkNsVr1xO9BkOppS3KLM47NRErpH0+YE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788456395; c=relaxed/simple; bh=6MZkHmI7KIdxZmtzWmbWfXmFLSbXSnS/AF5iFuCjuGM=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type; b=u/m6zH3cFDugXfWvTgksXdlkCck1cGuDq/B0gu678UtsjhvrIzxH7LtjN6g7s4IfhZDDu0/T85wswr59qfyM2KIX5ZSJ5BDA7HHAg5SrLedoVoM3mxyWcQvSrZpKL+ajMHaeZAlxYzy9ChY9gqBTuftOq74qg6ntjGnTrobTdqs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; dkim=pass (1024-bit key) header.d=goodmis.org header.i=@goodmis.org header.b=NIoAdcnC; arc=none smtp.client-ip=216.40.44.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=goodmis.org header.i=@goodmis.org header.b="NIoAdcnC" Received: from omf04.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay05.hostedemail.com (Postfix) with ESMTP id D0A5D405E2; Thu, 3 Sep 2026 17:26:26 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf04.hostedemail.com (Postfix) with ESMTPA id 27EB320030; Thu, 3 Sep 2026 17:26:25 +0000 (UTC) Date: Thu, 3 Sep 2026 13:27:28 -0400 From: Steven Rostedt To: LKML , Linux Trace Kernel Cc: Masami Hiramatsu , Mathieu Desnoyers , Vincent Donnefort Subject: [PATCH] ftrace: Add checking nr_subbufs to persistent ring buffer validation Message-ID: <20260903132728.7fb27d34@gandalf.local.home> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Stat-Signature: xm63i8kti5fzcdp3aym4uo8sc86cj3zr X-Rspamd-Server: rspamout06 X-Rspamd-Queue-Id: 27EB320030 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX18MTPDN1pO17eBclGPNQPbBTTtaEcie9Z0= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=goodmis.org; h=date:from:to:cc:subject:message-id:mime-version:content-type:content-transfer-encoding; s=dkim1; bh=Kx242b73O88THqGlqMnzySnHUjwHnJ8hlJwPqHlsHI4=; b=NIoAdcnCZwhRH6NcTIVihpkJJ5NvXHIlC7OADu5sN+BQntaIXkmW3kedJC693fghG+XTjZAF/8vqr9oPA9ZSGZCOFl6elpF/QjHcHQ+PTUTt79sWPS3ayr9udnXOf5OWkLTnYdoumISvSMwGf/nRwFnW4RlLW4LoGdCDkYo2ob4= X-HE-Tag: 1788456385-270618 X-HE-Meta: U2FsdGVkX18msQmni3doAfXqNixdA771BOOqF/FKKjxMBIhv0NFnI20vm2C199Gzqc8Alp7VEydBQ+eZHFYj0vux1kUbbeS2hFe8Zl+/hQ/5e6OPR+govPV5bcHXu40hl2AmgQilzU3/1ES7lF0G4X1rTmM0P0dwLHC++edcTJXKc9hNzG6inEVBtgwtu6stPvdECKvrnDr5YhoLXwVGYQM6DaXnmzu8tzwLWm9rvLpmpQrto0/RhntjgS0WymF/uSmJg9lZjqN2IPAgl7yndRHd3M74Hm3heJSnIt2CD4cys6oU7HrvgNyyvKdU7LB89SnfsvZvmrx+3VIGFjHanl4EvvY2ztcWS1pYkVYny01wYygHAaA4OJ1tTF6E2rREXWGz7iYG0RhmUa6xFxV4/Q== Content-Type: text/plain; charset="utf-8" From: Steven Rostedt 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 subbu= f array") Reported-by: sashiko-bot@kernel.org Closes: https://lore.kernel.org/all/20260901164836.D962D1F000E9@smtp.kernel= .org/ Signed-off-by: Steven Rostedt Reviewed-by: Vincent Donnefort --- 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; } =20 + if (meta->nr_subbufs !=3D nr_pages + 1) { + pr_info("Ring buffer boot meta [%d] invalid nr_subbufs\n", cpu); + return false; + } + buffers_start =3D meta->first_buffer; buffers_end =3D meta->first_buffer + (subbuf_size * meta->nr_subbufs); =20 --=20 2.53.0