From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 44D53282F1C for ; Sun, 6 Sep 2026 01:45:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788659155; cv=none; b=kn/UqHD2e5DnqgJyffeQHoiThIUzlP9wrhU/jKyXP+iNbwxs1o6P8LkrszY/mSo3CtyN4XWSQae8VqVlmLXJklXUuJ+YmJm+mWCuVflI+j6akxikpfy7CrUbipa+S9s0Lxx5JKwWlGp1wud3Cf+2+AG9LDnCPMpY+JS6dFybPNA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788659155; c=relaxed/simple; bh=F6KQeZdbVNU6nqzdbwbqOcfr7MGeBxYJ/WbkW5sRG8c=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=HKo6n2kr8s8iLi4mLvAsLhU7lWZvW6dRVyOA7lfaxoscT8wMtXissrOzNS36rJ7JAzgy6Tm34VszKLOyxIl4RsSciuD+F7X6nLIuMTiHJiEzJ3Ahp0fvdMKlSuSAgmvUy7LkSXq/wWEkcbSpnT27Qf24LmiOkN1MbVkDvnNw2QI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CoHi1z+Q; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="CoHi1z+Q" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4EC491F00ACA; Sun, 6 Sep 2026 01:45:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788659147; bh=zLOsuJy/tiOhVClCFWf0RybPYTPcY6Fl4v6aNVup9Uo=; h=Date:From:To:Cc:Subject:References; b=CoHi1z+Qxovjzof5XhSvjpGQs67mtSXap+BHU+7BI1yuF0SWmuR/YqWUxTEDaCBZL GO4dBQ5dHXUm7TEM+aEcX3qQgcCaXViyW0lPXcM6zWM2yoXDsPvmgUQ0esO6UTXxY0 w+C6YxuuT0RcdKiIcqdstRUxJUSCCnZpKAKFiV9tUK70b1rVOaPQw55Ulg/KfHf2AE n20G90RRGq9ST7HwJ4TUJTWXbMOMXcyYsZUYTklfa15Son2gw2uNCbZstiu3nJenzQ wMzwOvp3Yjbe+hReG4UIJBgv/qTg6aR7aoBjaM0W1LRH8Eoh/tb2qJNJSDA+1p7Ml4 LTYzDf0ex3fZg== Received: from rostedt by gandalf with local (Exim 4.99.4) (envelope-from ) id 1x31yC-00000006PQ8-0mtw; Sat, 05 Sep 2026 21:46:56 -0400 Message-ID: <20260906014656.049956688@kernel.org> User-Agent: quilt/0.69 Date: Sat, 05 Sep 2026 21:45:37 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Vincent Donnefort , sashiko-bot@kernel.org Subject: [for-linus][PATCH 06/12] ring-buffer: Add checking nr_subbufs to persistent ring buffer validation References: <20260906014531.720267751@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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. Link: https://patch.msgid.link/20260903132728.7fb27d34@gandalf.local.home Fixes: f5b95f1fa2ef3 ("ring-buffer: Validate the persistent meta data subbuf array") Reported-by: sashiko-bot@kernel.org Closes: https://lore.kernel.org/all/20260901164836.D962D1F000E9@smtp.kernel.org/ Reviewed-by: Vincent Donnefort Signed-off-by: Steven Rostedt --- 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 84fd4cdd486f..ff0a44aa578d 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1856,6 +1856,11 @@ 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