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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 17990C43381 for ; Fri, 22 Mar 2019 11:36:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D730A2082C for ; Fri, 22 Mar 2019 11:36:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553254590; bh=dq9HuEGGRW/3T/YRfbRwoBEfio/7b7suao690qwV8LE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=BvlTC1i0eb1pyd0KthrVOXP4dodYgRQ39MxhacNQDD35wngC7eVlIvLzN9W0//SAW yILu7ekDSp2OCXdf5x4Ho+njxNXlnmHj2vhuvj42JnBOlmfp/sNMPJEmXIqJ3N+dh8 diXp/MgV1DEKQFzcmE7I7IKK6iCVpX0Lvsz6TTBM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730713AbfCVLg3 (ORCPT ); Fri, 22 Mar 2019 07:36:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:37764 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729848AbfCVLgZ (ORCPT ); Fri, 22 Mar 2019 07:36:25 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3B29C2082C; Fri, 22 Mar 2019 11:36:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553254584; bh=dq9HuEGGRW/3T/YRfbRwoBEfio/7b7suao690qwV8LE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wqXpnmWWCSKlMyT9DVBcZB+mgGHOk4isFK3dsxXIB0xqMrSrmqPgGXWyGD9CDivId HcW42K+0ohZr554gNpkEgMN38sG5vD6vUkgTc52WKwh+0FIuTf8khESGkDOEfi3aAF qLAkp9LuwJc4y2NDuWTEnAZPPy0B8o2XvXpMMH0A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ferry Toth , Andy Shevchenko , Mika Westerberg , "Rafael J. Wysocki" Subject: [PATCH 4.4 181/230] ACPI / device_sysfs: Avoid OF modalias creation for removed device Date: Fri, 22 Mar 2019 12:15:19 +0100 Message-Id: <20190322111249.480620240@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190322111236.796964179@linuxfoundation.org> References: <20190322111236.796964179@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andy Shevchenko commit f16eb8a4b096514ac06fb25bf599dcc792899b3d upstream. If SSDT overlay is loaded via ConfigFS and then unloaded the device, we would like to have OF modalias for, already gone. Thus, acpi_get_name() returns no allocated buffer for such case and kernel crashes afterwards: ACPI: Host-directed Dynamic ACPI Table Unload ads7950 spi-PRP0001:00: Dropping the link to regulator.0 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 #PF error: [normal kernel read fault] PGD 80000000070d6067 P4D 80000000070d6067 PUD 70d0067 PMD 0 Oops: 0000 [#1] SMP PTI CPU: 0 PID: 40 Comm: kworker/u4:2 Not tainted 5.0.0+ #96 Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 2015.01.21:18.19.48 Workqueue: kacpi_hotplug acpi_device_del_work_fn RIP: 0010:create_of_modalias.isra.1+0x4c/0x150 Code: 00 00 48 89 44 24 18 31 c0 48 8d 54 24 08 48 c7 44 24 10 00 00 00 00 48 c7 44 24 08 ff ff ff ff e8 7a b0 03 00 48 8b 4c 24 10 <0f> b6 01 84 c0 74 27 48 c7 c7 00 09 f4 a5 0f b6 f0 8d 50 20 f6 04 RSP: 0000:ffffa51040297c10 EFLAGS: 00010246 RAX: 0000000000001001 RBX: 0000000000000785 RCX: 0000000000000000 RDX: 0000000000001001 RSI: 0000000000000286 RDI: ffffa2163dc042e0 RBP: ffffa216062b1196 R08: 0000000000001001 R09: ffffa21639873000 R10: ffffffffa606761d R11: 0000000000000001 R12: ffffa21639873218 R13: ffffa2163deb5060 R14: ffffa216063d1010 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffffa2163e000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000007114000 CR4: 00000000001006f0 Call Trace: __acpi_device_uevent_modalias+0xb0/0x100 spi_uevent+0xd/0x40 ... In order to fix above let create_of_modalias() check the status returned by acpi_get_name() and bail out in case of failure. Fixes: 8765c5ba1949 ("ACPI / scan: Rework modalias creation when "compatible" is present") Link: https://bugzilla.kernel.org/show_bug.cgi?id=201381 Reported-by: Ferry Toth Tested-by: Ferry Toth Signed-off-by: Andy Shevchenko Reviewed-by: Mika Westerberg Cc: 4.1+ # 4.1+ Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/device_sysfs.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/acpi/device_sysfs.c +++ b/drivers/acpi/device_sysfs.c @@ -202,11 +202,15 @@ static int create_of_modalias(struct acp { struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; const union acpi_object *of_compatible, *obj; + acpi_status status; int len, count; int i, nval; char *c; - acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf); + status = acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf); + if (ACPI_FAILURE(status)) + return -ENODEV; + /* DT strings are all in lower case */ for (c = buf.pointer; *c != '\0'; c++) *c = tolower(*c);