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 X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D0F0C4321D for ; Thu, 23 Aug 2018 05:28:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9A4432086B for ; Thu, 23 Aug 2018 05:28:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Da0Xkp07" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9A4432086B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728539AbeHWI4k (ORCPT ); Thu, 23 Aug 2018 04:56:40 -0400 Received: from mail-pl0-f66.google.com ([209.85.160.66]:34527 "EHLO mail-pl0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728360AbeHWI4k (ORCPT ); Thu, 23 Aug 2018 04:56:40 -0400 Received: by mail-pl0-f66.google.com with SMTP id f6-v6so1885158plo.1 for ; Wed, 22 Aug 2018 22:28:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=fHH5TD6YRf77MzHh7sDvwWo7y4Ij078zVJ7PZ5B6Jc8=; b=Da0Xkp07FNXC9kMn04fMUCIVzTR8ZadAm54ZvN9R8lI96iBWYlNVePhPinAn4w8yOp +WFM+IXrIs3e10UILm9gOGulNpRf5t4NBbQOrO5vp7QkjWWglyV863nYe6scG70E02sZ Tr9q9MwixgybejhaXW2QWpf/y2uxTMCzJfPRqcO+M689AQXF7iL6CyqmW0lHgy7vm8+b lvhiHfr1zTHhGoTI46h3xY1qyR3SyL/2pa18VZgP9MxnH6bSWMxcpe351isjBayhxRjk CdgAG6mX9T0zAHkXPuMaj2R9Ap2y0WmCe4V8rlQ2rXbukKSgW8SBe4Wc1bODR1VERmhs pyKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=fHH5TD6YRf77MzHh7sDvwWo7y4Ij078zVJ7PZ5B6Jc8=; b=YvB/WxnP09EJ57fW5Obz70ZZ1QW3+/+Jsw9v8nbNnKpefkhwX+UdQk66+0G2W6RUBq JTEByEeay38kjyQvBnlHd3FueiIJWD6TpQMUSpZxDouk+h907shE+97GUfhs7N2hSxd8 hg8VgKEYuWg2dFHYCoaqvKutlD5DH1nHtNg8NzVv1jncCYFtiI1zrzNIWEDoJRctv/Va +rCHpyGU8yy7v3xw6hkjio8xeWfx/vTICRWO63HSgBGZu6YtM1jzdeydhD8TcZGz/jph R5J9yPfsuszXiVOIu/2YFlSL2D9cEqxuFJ3QhYQZ5BkN4E0FalSFW2jypWzwxFdQSc/M cpRg== X-Gm-Message-State: AOUpUlGMu9e5zQtVGGMhu2oZZnuuW9mS0AZBXBGaurxxcmB0SQzA/i0e PZuIcKkipar02z5+uqTcjxXSGwkT X-Google-Smtp-Source: AA+uWPwhrgM4t7wsYuCL4ibtnuTjZ+UGHfsxQfyvpem9qlFMSh31IdfaRFUp9IMTRumWPdh9J9zgYw== X-Received: by 2002:a17:902:24e1:: with SMTP id l30-v6mr25548057plg.315.1535002125000; Wed, 22 Aug 2018 22:28:45 -0700 (PDT) Received: from blueforge.nvidia.com (searspoint.nvidia.com. [216.228.112.21]) by smtp.gmail.com with ESMTPSA id k5-v6sm7342405pfj.30.2018.08.22.22.28.43 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 22 Aug 2018 22:28:43 -0700 (PDT) From: john.hubbard@gmail.com X-Google-Original-From: jhubbard@nvidia.com To: Tomas Winkler Cc: LKML , John Hubbard , Arnd Bergmann , Greg Kroah-Hartman Subject: [PATCH] mei: fix use-after-free in mei_cl_write Date: Wed, 22 Aug 2018 22:28:40 -0700 Message-Id: <20180823052840.16364-1-jhubbard@nvidia.com> X-Mailer: git-send-email 2.18.0 X-NVConfidentiality: public Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: John Hubbard KASAN reports a use-after-free during startup, in mei_cl_write: BUG: KASAN: use-after-free in mei_cl_write+0x601/0x870 [mei] (drivers/misc/mei/client.c:1770) This is caused by commit 98e70866aacb ("mei: add support for variable length mei headers."), which changed the return value from len, to buf-size. That ends up using a stale buf pointer, because in some situations, the cb (callback) is deleted before it gets here. However, fortunately, len remains unchanged throughout the function (and I don't see anything else that would require re-reading buf->size either), so the fix is to simply revert the change, and return len, as before. CC: Tomas Winkler CC: Arnd Bergmann CC: Greg Kroah-Hartman Signed-off-by: John Hubbard --- drivers/misc/mei/client.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c index 4ab6251d418e..ebdcf0b450e2 100644 --- a/drivers/misc/mei/client.c +++ b/drivers/misc/mei/client.c @@ -1767,7 +1767,7 @@ ssize_t mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb) } } - rets = buf->size; + rets = len; err: cl_dbg(dev, cl, "rpm: autosuspend\n"); pm_runtime_mark_last_busy(dev->dev); -- 2.18.0