From patchwork Thu Sep 6 21:07:48 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brad Love X-Patchwork-Id: 10591071 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 790F65A4 for ; Thu, 6 Sep 2018 21:08:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5E5732A3F9 for ; Thu, 6 Sep 2018 21:08:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 521D92A432; Thu, 6 Sep 2018 21:08:05 +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 D99932A3F9 for ; Thu, 6 Sep 2018 21:08:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727736AbeIGBpT (ORCPT ); Thu, 6 Sep 2018 21:45:19 -0400 Received: from sub5.mail.dreamhost.com ([208.113.200.129]:57689 "EHLO homiemail-a119.g.dreamhost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727093AbeIGBpT (ORCPT ); Thu, 6 Sep 2018 21:45:19 -0400 Received: from homiemail-a119.g.dreamhost.com (localhost [127.0.0.1]) by homiemail-a119.g.dreamhost.com (Postfix) with ESMTP id 0314C6000D731; Thu, 6 Sep 2018 14:08:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=nextdimension.cc; h=from :to:cc:subject:date:message-id:in-reply-to:references; s= nextdimension.cc; bh=N89a7TvVXDPIhiCYPrtQAQe15KQ=; b=jjAioRVPutD FaErsDJXBFwIhGbTE4P+sqK/liN1M4fZt47owjcOuGsCOrKrY9B3vrnolhRgm0jY o8eSCQ5Den6K52xbOv4lbQjMHeNUxV3EaEe8UpbpQ6+DbcsbID8IWXrKfuhLogib R7hfmBtLTFKXQqsetW8ppnduCSbNS34A= Received: from localhost.localdomain (66-90-189-166.dyn.grandenetworks.net [66.90.189.166]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: brad@nextdimension.ws) by homiemail-a119.g.dreamhost.com (Postfix) with ESMTPSA id A5C366000D72A; Thu, 6 Sep 2018 14:08:02 -0700 (PDT) From: Brad Love To: linux-media@vger.kernel.org, mkrufky@linuxtv.org Cc: Brad Love Subject: [PATCH 1/2] au0828: cannot kfree dev before usb disconnect Date: Thu, 6 Sep 2018 16:07:48 -0500 Message-Id: <1536268069-25435-2-git-send-email-brad@nextdimension.cc> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1536268069-25435-1-git-send-email-brad@nextdimension.cc> References: <1536268069-25435-1-git-send-email-brad@nextdimension.cc> 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 If au0828_analog_register fails, the dev is kfree'd and then flow jumps to done, which can call au0828_usb_disconnect. Since all USB error codes are negative, au0828_usb_disconnect will be called. The problem is au0828_usb_disconnect uses dev, if dev is NULL then there is immediate oops encountered. [ 7.454307] au0828: au0828_usb_probe() au0282_dev_register failed to register on V4L2 [ 7.454323] BUG: unable to handle kernel NULL pointer dereference at 0000000000000050 [ 7.454421] PGD 0 P4D 0 [ 7.454457] Oops: 0002 [#1] SMP PTI [ 7.454500] CPU: 1 PID: 262 Comm: systemd-udevd Tainted: P O 4.18.3 #1 [ 7.454584] Hardware name: Google Panther/Panther, BIOS MattDevo 04/27/2015 [ 7.454670] RIP: 0010:_raw_spin_lock_irqsave+0x2c/0x50 [ 7.454725] Code: 44 00 00 55 48 89 e5 41 54 53 48 89 fb 9c 58 0f 1f 44 00 00 49 89 c4 fa 66 0f 1f 44 00 00 e8 db 23 1b ff 31 c0 ba 01 00 00 00 0f b1 13 85 c0 75 08 4c 89 e0 5b 41 5c 5d c3 89 c6 48 89 df e8 [ 7.455004] RSP: 0018:ffff9130f53ef988 EFLAGS: 00010046 [ 7.455063] RAX: 0000000000000000 RBX: 0000000000000050 RCX: 0000000000000000 [ 7.455139] RDX: 0000000000000001 RSI: 0000000000000003 RDI: 0000000000000050 [ 7.455216] RBP: ffff9130f53ef998 R08: 0000000000000018 R09: 0000000000000090 [ 7.455292] R10: ffffed4cc53cb000 R11: ffffed4cc53cb108 R12: 0000000000000082 [ 7.455369] R13: ffff9130cf2c6188 R14: 0000000000000000 R15: 0000000000000018 [ 7.455447] FS: 00007f2ff8514cc0(0000) GS:ffff9130fcb00000(0000) knlGS:0000000000000000 [ 7.455535] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 7.455597] CR2: 0000000000000050 CR3: 00000001753f0002 CR4: 00000000000606a0 [ 7.455675] Call Trace: [ 7.455713] __wake_up_common_lock+0x65/0xc0 [ 7.455764] __wake_up+0x13/0x20 [ 7.455808] ir_lirc_unregister+0x57/0xe0 [rc_core] [ 7.455865] rc_unregister_device+0xa0/0xc0 [rc_core] [ 7.455935] au0828_rc_unregister+0x25/0x40 [au0828] [ 7.455999] au0828_usb_disconnect+0x33/0x80 [au0828] [ 7.456064] au0828_usb_probe.cold.16+0x8d/0x2aa [au0828] [ 7.456130] usb_probe_interface+0xf1/0x300 [ 7.456184] driver_probe_device+0x2e3/0x460 [ 7.456235] __driver_attach+0xe4/0x110 [ 7.456282] ? driver_probe_device+0x460/0x460 [ 7.456335] bus_for_each_dev+0x74/0xb0 [ 7.456385] ? kmem_cache_alloc_trace+0x15d/0x1d0 [ 7.456441] driver_attach+0x1e/0x20 [ 7.456485] bus_add_driver+0x159/0x230 [ 7.456532] driver_register+0x70/0xc0 [ 7.456578] usb_register_driver+0x7f/0x140 [ 7.456626] ? 0xffffffffc0474000 [ 7.456674] au0828_init+0xbc/0x1000 [au0828] [ 7.456725] do_one_initcall+0x4a/0x1c9 [ 7.456771] ? _cond_resched+0x19/0x30 [ 7.456817] ? kmem_cache_alloc_trace+0x15d/0x1d0 [ 7.456873] do_init_module+0x60/0x210 [ 7.456918] load_module+0x221b/0x2710 [ 7.456966] ? vfs_read+0xf5/0x120 [ 7.457010] __do_sys_finit_module+0xbd/0x120 [ 7.457061] ? __do_sys_finit_module+0xbd/0x120 [ 7.457115] __x64_sys_finit_module+0x1a/0x20 [ 7.457166] do_syscall_64+0x5b/0x110 [ 7.457210] entry_SYSCALL_64_after_hwframe+0x49/0xbe Signed-off-by: Brad Love --- drivers/media/usb/au0828/au0828-core.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/media/usb/au0828/au0828-core.c b/drivers/media/usb/au0828/au0828-core.c index cd363a2..257ae0d 100644 --- a/drivers/media/usb/au0828/au0828-core.c +++ b/drivers/media/usb/au0828/au0828-core.c @@ -629,7 +629,6 @@ static int au0828_usb_probe(struct usb_interface *interface, pr_err("%s() au0282_dev_register failed to register on V4L2\n", __func__); mutex_unlock(&dev->lock); - kfree(dev); goto done; }