From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E63BFC433FE for ; Wed, 23 Nov 2022 08:55:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236745AbiKWIzp (ORCPT ); Wed, 23 Nov 2022 03:55:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58974 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236749AbiKWIzo (ORCPT ); Wed, 23 Nov 2022 03:55:44 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9721CE932B for ; Wed, 23 Nov 2022 00:55:43 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 3399061B10 for ; Wed, 23 Nov 2022 08:55:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1CE67C433D7; Wed, 23 Nov 2022 08:55:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1669193742; bh=1RVzD4SAWU/WqbChixPy4VM0dNOktno0GCWcdiWHjZg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PhJlMUhEP/fJmTeGsCy2CI/oExnxG7D428b8gyKXGKW7t+/J8CukHaF6SLIiBWmD7 1ZatbhKut/bJrVHvt9VdWtdZUcL0vRvWRYnRS1yt7THovGNr/QYcm1xqgmKjjKkgRD XjbejJFX2l1L5GEbk98XMYRd4kllPDzEQzpp3SHM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Daniil Tatianin , "Steven Rostedt (Google)" Subject: [PATCH 4.9 48/76] ring_buffer: Do not deactivate non-existant pages Date: Wed, 23 Nov 2022 09:50:47 +0100 Message-Id: <20221123084548.317910865@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221123084546.742331901@linuxfoundation.org> References: <20221123084546.742331901@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Daniil Tatianin commit 56f4ca0a79a9f1af98f26c54b9b89ba1f9bcc6bd upstream. rb_head_page_deactivate() expects cpu_buffer to contain a valid list of ->pages, so verify that the list is actually present before calling it. Found by Linux Verification Center (linuxtesting.org) with the SVACE static analysis tool. Link: https://lkml.kernel.org/r/20221114143129.3534443-1-d-tatianin@yandex-team.ru Cc: stable@vger.kernel.org Fixes: 77ae365eca895 ("ring-buffer: make lockless") Signed-off-by: Daniil Tatianin Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/ring_buffer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1267,9 +1267,9 @@ static void rb_free_cpu_buffer(struct ri free_buffer_page(cpu_buffer->reader_page); - rb_head_page_deactivate(cpu_buffer); - if (head) { + rb_head_page_deactivate(cpu_buffer); + list_for_each_entry_safe(bpage, tmp, head, list) { list_del_init(&bpage->list); free_buffer_page(bpage);