From patchwork Tue Apr 2 00:43:17 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shuah X-Patchwork-Id: 10880863 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6CBE0139A for ; Tue, 2 Apr 2019 00:43:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 55EA328857 for ; Tue, 2 Apr 2019 00:43:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 540B7288CE; Tue, 2 Apr 2019 00:43:32 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 B65A328857 for ; Tue, 2 Apr 2019 00:43:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728682AbfDBAnV (ORCPT ); Mon, 1 Apr 2019 20:43:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:35660 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726635AbfDBAnV (ORCPT ); Mon, 1 Apr 2019 20:43:21 -0400 Received: from shuah-t480s.internal (c-24-9-64-241.hsd1.co.comcast.net [24.9.64.241]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 98A0920883; Tue, 2 Apr 2019 00:43:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554165800; bh=s/stWospmmZEnYk2B722eqev90ya5RvTogKTl6p/ZH0=; h=From:To:Cc:Subject:Date:From; b=IN6BG6shkT7wVXjuePTNMr5FrdldwXCT/eGWkG7qwddGiVdHYonWo3Y6RMObQakSp qzHTVdx8LuMuimUQ7LapfSXEdVKrPvwfCgZA28kslWfHwpCUf3uwmpsMt0YyaSjhdf KGaGOBsogQXKXfOuy0F1e1rcn4RHVU7gRc5EhSm4= From: Shuah Khan To: mchehab@kernel.org, hverkuil@xs4all.nl Cc: Shuah Khan , keescook@chromium.org, niklas.soderlund+renesas@ragnatech.se, sakari.ailus@linux.intel.com, colin.king@canonical.com, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] au0828: Fix NULL pointer dereference in au0828_analog_stream_enable() Date: Mon, 1 Apr 2019 18:43:17 -0600 Message-Id: <20190402004318.30309-1-shuah@kernel.org> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Fix au0828_analog_stream_enable() to check if device is in the right state first. When unbind happens while bind is in progress, usbdev pointer could be invalid in au0828_analog_stream_enable() and a call to usb_ifnum_to_if() will result in the null pointer dereference. This problem is found with the new media_dev_allocator.sh test. kernel: [ 590.359623] BUG: unable to handle kernel NULL pointer dereference at 00000000000004e8 kernel: [ 590.359627] #PF error: [normal kernel read fault] kernel: [ 590.359629] PGD 0 P4D 0 kernel: [ 590.359632] Oops: 0000 [#1] SMP PTI kernel: [ 590.359634] CPU: 3 PID: 1458 Comm: v4l_id Not tainted 5.1.0-rc2+ #30 kernel: [ 590.359636] Hardware name: Dell Inc. OptiPlex 7 90/0HY9JP, BIOS A18 09/24/2013 kernel: [ 590.359641] RIP: 0010:usb_ifnum_to_if+0x6/0x60 kernel: [ 590.359643] Code: 5d 41 5e 41 5f 5d c3 48 83 c4 10 b8 fa ff ff ff 5b 41 5c 41 5d 41 5e 41 5f 5d c3 b8 fa ff ff ff c3 0f 1f 00 6 6 66 66 66 90 55 <48> 8b 97 e8 04 00 00 48 89 e5 48 85 d2 74 41 0f b6 4a 04 84 c 9 74 kernel: [ 590.359645] RSP: 0018:ffffad3cc3c1fc00 EFLAGS: 00010246 kernel: [ 590.359646] RAX: 0000000000000000 RBX: ffff8ded b1f3c000 RCX: 1f377e4500000000 kernel: [ 590.359648] RDX: ffff8dedfa3a6b50 RSI: 00000000 00000000 RDI: 0000000000000000 kernel: [ 590.359649] RBP: ffffad3cc3c1fc28 R08: 00000000 8574acc2 R09: ffff8dedfa3a6b50 kernel: [ 590.359650] R10: 0000000000000001 R11: 00000000 00000000 R12: 0000000000000000 kernel: [ 590.359652] R13: ffff8dedb1f3f0f0 R14: ffffffff adcf7ec0 R15: 0000000000000000 kernel: [ 590.359654] FS: 00007f7917198540(0000) GS:ffff 8dee258c0000(0000) knlGS:0000000000000000 kernel: [ 590.359655] CS: 0010 DS: 0000 ES: 0000 CR0: 00 00000080050033 kernel: [ 590.359657] CR2: 00000000000004e8 CR3: 00000001 a388e002 CR4: 00000000000606e0 kernel: [ 590.359658] Call Trace: kernel: [ 590.359664] ? au0828_analog_stream_enable+0x2c/0x180 kernel: [ 590.359666] au0828_v4l2_open+0xa4/0x110 kernel: [ 590.359670] v4l2_open+0x8b/0x120 kernel: [ 590.359674] chrdev_open+0xa6/0x1c0 kernel: [ 590.359676] ? cdev_put.part.3+0x20/0x20 kernel: [ 590.359678] do_dentry_open+0x1f6/0x360 kernel: [ 590.359681] vfs_open+0x2f/0x40 kernel: [ 590.359684] path_openat+0x299/0xc20 kernel: [ 590.359688] do_filp_open+0x9b/0x110 kernel: [ 590.359695] ? _raw_spin_unlock+0x27/0x40 kernel: [ 590.359697] ? __alloc_fd+0xb2/0x160 kernel: [ 590.359700] do_sys_open+0x1ba/0x260 kernel: [ 590.359702] ? do_sys_open+0x1ba/0x260 kernel: [ 590.359712] __x64_sys_openat+0x20/0x30 kernel: [ 590.359715] do_syscall_64+0x5a/0x120 kernel: [ 590.359718] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: Shuah Khan --- drivers/media/usb/au0828/au0828-video.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/media/usb/au0828/au0828-video.c b/drivers/media/usb/au0828/au0828-video.c index 7876c897cc1d..106a49da39f9 100644 --- a/drivers/media/usb/au0828/au0828-video.c +++ b/drivers/media/usb/au0828/au0828-video.c @@ -758,6 +758,9 @@ static int au0828_analog_stream_enable(struct au0828_dev *d) dprintk(1, "au0828_analog_stream_enable called\n"); + if (test_bit(DEV_DISCONNECTED, &d->dev_state)) + return -ENODEV; + iface = usb_ifnum_to_if(d->usbdev, 0); if (iface && iface->cur_altsetting->desc.bAlternateSetting != 5) { dprintk(1, "Changing intf#0 to alt 5\n");