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 7C69BC32792 for ; Tue, 23 Aug 2022 08:36:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344413AbiHWIf3 (ORCPT ); Tue, 23 Aug 2022 04:35:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347254AbiHWIcS (ORCPT ); Tue, 23 Aug 2022 04:32:18 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AEAE4FEF; Tue, 23 Aug 2022 01:16:26 -0700 (PDT) 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 ams.source.kernel.org (Postfix) with ESMTPS id CCBF4B81C36; Tue, 23 Aug 2022 08:16:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3E957C433C1; Tue, 23 Aug 2022 08:16:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661242584; bh=j3Uq1S6p1wxJpc6tFreDzh8tlF7KqJESrAe7E/cF9bg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XEfW3uGWgZC8JSvw8Hs5+lLI8uPWiORQw7fyFZ/YKLrdlBt8Y47cY+U8G2w8DUU9t w8YAjr96vBF4x7CS927PKegBVc48Pzj7aVnVu7P3GIX0AI2/NBnITaHLPbeJA3lzEn Ic2/k+Mn9ZPo7FqGE3cIPuEGLyJ3b+vv2PsqZJck= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Schspa Shi , Cornelia Huck , Alex Williamson , Sasha Levin Subject: [PATCH 4.9 095/101] vfio: Clear the caps->buf to NULL after free Date: Tue, 23 Aug 2022 10:04:08 +0200 Message-Id: <20220823080038.199805303@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080034.579196046@linuxfoundation.org> References: <20220823080034.579196046@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: linux-kernel@vger.kernel.org From: Schspa Shi [ Upstream commit 6641085e8d7b3f061911517f79a2a15a0a21b97b ] On buffer resize failure, vfio_info_cap_add() will free the buffer, report zero for the size, and return -ENOMEM. As additional hardening, also clear the buffer pointer to prevent any chance of a double free. Signed-off-by: Schspa Shi Reviewed-by: Cornelia Huck Link: https://lore.kernel.org/r/20220629022948.55608-1-schspa@gmail.com Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin --- drivers/vfio/vfio.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 881fc3a55edc..5798965f42b5 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -1793,6 +1793,7 @@ struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps, buf = krealloc(caps->buf, caps->size + size, GFP_KERNEL); if (!buf) { kfree(caps->buf); + caps->buf = NULL; caps->size = 0; return ERR_PTR(-ENOMEM); } -- 2.35.1