From patchwork Sat May 26 00:59:36 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tetsuo Handa X-Patchwork-Id: 10428793 X-Patchwork-Delegate: rjw@sisk.pl Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id C232F60225 for ; Sat, 26 May 2018 01:00:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A5AE32982C for ; Sat, 26 May 2018 01:00:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 99F4C2982A; Sat, 26 May 2018 01:00:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A127D2982A for ; Sat, 26 May 2018 01:00:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030838AbeEZBAG (ORCPT ); Fri, 25 May 2018 21:00:06 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:56221 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030834AbeEZBAG (ORCPT ); Fri, 25 May 2018 21:00:06 -0400 Received: from fsav103.sakura.ne.jp (fsav103.sakura.ne.jp [27.133.134.230]) by www262.sakura.ne.jp (8.14.5/8.14.5) with ESMTP id w4Q0xhpG025137; Sat, 26 May 2018 09:59:43 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav103.sakura.ne.jp (F-Secure/fsigk_smtp/530/fsav103.sakura.ne.jp); Sat, 26 May 2018 09:59:43 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/530/fsav103.sakura.ne.jp) Received: from ccsecurity.localdomain (softbank126074194044.bbtec.net [126.74.194.44]) (authenticated bits=0) by www262.sakura.ne.jp (8.14.5/8.14.5) with ESMTP id w4Q0xcvt025065 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Sat, 26 May 2018 09:59:43 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) From: Tetsuo Handa To: "Rafael J. Wysocki" , Pavel Machek , Len Brown Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Tetsuo Handa , syzbot Subject: [PATCH] PM / hibernate: Fix oops at snapshot_write(). Date: Sat, 26 May 2018 09:59:36 +0900 Message-Id: <1527296376-3540-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> X-Mailer: git-send-email 1.8.3.1 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP syzbot is reporting NULL pointer dereference at snapshot_write() [1]. This is because data->handle is zero-cleared by ioctl(SNAPSHOT_FREE). Fix this by checking data_of(data->handle) != NULL before using it. [1] https://syzkaller.appspot.com/bug?id=828a3c71bd344a6de8b6a31233d51a72099f27fd Signed-off-by: Tetsuo Handa Reported-by: syzbot Cc: Rafael J. Wysocki Cc: Len Brown Cc: Pavel Machek --- kernel/power/user.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/power/user.c b/kernel/power/user.c index 75c959d..abd2255 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -186,6 +186,11 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf, res = PAGE_SIZE - pg_offp; } + if (!data_of(data->handle)) { + res = -EINVAL; + goto unlock; + } + res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp, buf, count); if (res > 0)