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 8E34158F07B; Thu, 17 Sep 2026 15:36:17 +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=1789659383; cv=none; b=FXNKKI7d7zkztmJeTBKOJXVsTojwORqH/B65pjKKkBf7JSC5zz0eKt4Bx5HNAtzcWoCU2ejh+EyAq9sDpH1vbM6JFsknX5ewAjuX1r5vA31HcpCicesiEE/km6JKj5YLkr040LACXVI15Bff3XDOEilCL14dEyZCcUUf0DkYKx8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789659383; c=relaxed/simple; bh=8oVZ/UUIdgEQ3w0WGGQB5BBdILx8zevcYlonEKJEBiw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=g8DLi0Zi5YVN7yIOfJ7rQIUBsk1S/2urbLEeafySW4GeBJ0sYaO2t5PlZlX7f6sseeq7v7y0ZWBDH6n3nLb6IQvNO8YCy6KLnrU6SE1Ju1ZO7YLOxk27ljuHGQaWc9xQtkz5nsUwWQN4rOP2Wy7KX8vwxXsSk44QOTueIBCytn8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=p0VQList; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="p0VQList" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A8B2C1F00893; Thu, 17 Sep 2026 15:36:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789659374; bh=qLQ7p9kD8yiWhf3Z+WuG9aIwJ61F7xdY6slmJyDisHE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=p0VQListN0Xex33dIoqXXsFIRKeznjxoxgLOjg7S0ccSjVZHwQjpvz3xZpOXk2amE hQQO8+rQh47DpU5Qwyo/siAL449H8nO7MILVbwNs5BDjuJG7pB1Qcs+LQvlP37AOIf /vVgxxlBYPKv/b/mBUk8ROyb087Fao0kbTmNB+5c= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, sashiko-bot@kernel.org, Vincent Donnefort , Steven Rostedt , Sasha Levin Subject: [PATCH 7.2 234/733] ring-buffer: Add checking nr_subbufs to persistent ring buffer validation Date: Thu, 17 Sep 2026 16:09:02 +0100 Message-ID: <20260917151357.067023815@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260917151350.597953846@linuxfoundation.org> References: <20260917151350.597953846@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steven Rostedt [ Upstream commit 6c001a62c34f13fe1c6a24304c289b387d9e697d ] 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 Signed-off-by: Sasha Levin --- 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 1925ee9cc36da..70e43fe3a1006 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1836,6 +1836,11 @@ 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