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=-16.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 60D48C07E9B for ; Sat, 10 Jul 2021 06:04:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3B447613E9 for ; Sat, 10 Jul 2021 06:04:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231827AbhGJGGo (ORCPT ); Sat, 10 Jul 2021 02:06:44 -0400 Received: from smtprelay-out1.synopsys.com ([149.117.73.133]:50552 "EHLO smtprelay-out1.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229690AbhGJGGn (ORCPT ); Sat, 10 Jul 2021 02:06:43 -0400 Received: from mailhost.synopsys.com (mdc-mailhost1.synopsys.com [10.225.0.209]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (Client CN "mailhost.synopsys.com", Issuer "SNPSica2" (verified OK)) by smtprelay-out1.synopsys.com (Postfix) with ESMTPS id EFAE840170; Sat, 10 Jul 2021 06:03:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=synopsys.com; s=mail; t=1625897038; bh=c0ky0nucYPpag8qixdlzPW+7JgbM55OBHHAlv3x3TCU=; h=Date:From:Subject:To:Cc:From; b=cu+boN42aw7xlcu3rDPkoBu2FTBz+YJRj3mKIb7T0We/B7WeQ4Bvs9XQ8Sy0hychI S97IPh1MQSNEcbbiKWn22DRv+yE0ZDgNmpkrQo1QgYH/1NVP2wUpfMLrFzKXDgO6YS 9HwShXbg7CY3M6MJa/XBlEGkOzdS2bXLKDmVYqCPy2zsSJ2k0yJ7bYb0c79hK5tftO 3EgUzYPDuaOxgFbtBidZcN8lYoAQwwk98k/D6tcBf8ylgnIxv8HGsjbaptnBJiB2n5 9+ROsbOu3H0sV1NsdcYPbOaMJxYPvKh1bIWfx3+Wphxh5TBmvronxjJ5VXwNa7qfFE 16iPG4dx4OlLw== Received: from razpc-HP (razpc-hp.internal.synopsys.com [10.116.75.64]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (Client did not present a certificate) by mailhost.synopsys.com (Postfix) with ESMTPSA id 9C647A005D; Sat, 10 Jul 2021 06:03:53 +0000 (UTC) Received: by razpc-HP (sSMTP sendmail emulation); Sat, 10 Jul 2021 10:03:51 +0400 Date: Sat, 10 Jul 2021 10:03:51 +0400 Message-Id: X-SNPS-Relay: synopsys.com From: Artur Petrosyan Subject: [RFC PATCH] usb: phy: Fix handle page fault on usb_phy_uevent To: Felipe Balbi , Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Grzegorz Jaszczyk , Peter Chen Cc: Artur Petrosyan , Thinh Nguyen Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When the dwc2 platform device is removed, it unregisters the generic phy. usb_remove_phy() is called and the dwc2 usb_phy is removed from the "phy_list", but the uevent may still attempt to access the stale data resulting in a page fault bug. Currently we can't access the usb_phy from the "phy_list" after the device is removed. As a quick fix, check if the phy_list is empty before getting the usb_phy and ignore the uevent otherwise. [ 84.949345] BUG: unable to handle page fault for address:00000007935688d8 [ 84.949349] #PF: supervisor read access in kernel mode [ 84.949351] #PF: error_code(0x0000) - not-present page [ 84.949353] PGD 0 P4D 0 [ 84.949356] Oops: 0000 [#1] SMP PTI [ 84.949360] CPU: 2 PID: 2081 Comm: rmmod Not tainted 5.13.0-rc4-snps-16547-ga8534cb092d7-dirty #32 [ 84.949363] Hardware name: Hewlett-Packard HP Z400 Workstation/0B4Ch, BIOS 786G3 v03.54 11/02/2011 [ 84.949365] RIP: 0010:usb_phy_uevent+0x99/0x121 [ 84.949372] Code: 8d 83 f8 00 00 00 48 3d b0 12 22 94 74 05 4c 3b 23 75 5b 8b 83 9c 00 00 00 be 32 00 00 00 48 8d 7c 24 04 48 c7 c2 d4 5d 7b 93 <48> 8b 0c c5 e0 88 56 93 e8 0f 63 8a ff 8b 83 98 00 00 00 be 32 00 [ 84.949375] RSP: 0018:ffffa46bc0f2fc70 EFLAGS: 00010246 [ 84.949378] RAX: 00000000ffffffff RBX: ffffffff942211b8 RCX: 0000000000000027 [ 84.949380] RDX: ffffffff937b5dd4 RSI: 0000000000000032 RDI: ffffa46bc0f2fc74 [ 84.949383] RBP: ffff94a306613000 R08: 0000000000000000 R09: 00000000fffeffff [ 84.949385] R10: ffffa46bc0f2faa8 R11: ffffa46bc0f2faa0 R12: ffff94a30186d410 [ 84.949387] R13: ffff94a32d188a80 R14: ffff94a30029f960 R15: ffffffff93522dd0 [ 84.949389] FS: 00007efdbd417540(0000) GS:ffff94a513a80000(0000) knlGS:0000000000000000 [ 84.949392] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 84.949394] CR2: 00000007935688d8 CR3: 0000000165606000 CR4: 00000000000006e0 [ 84.949396] Call Trace: [ 84.949401] dev_uevent+0x190/0x1ad [ 84.949408] kobject_uevent_env+0x18e/0x46c [ 84.949414] device_release_driver_internal+0x17f/0x18e [ 84.949418] bus_remove_device+0xd3/0xe5 [ 84.949421] device_del+0x1c3/0x31d [ 84.949425] ? kobject_put+0x97/0xa8 [ 84.949428] platform_device_del+0x1c/0x63 [ 84.949432] platform_device_unregister+0xa/0x11 [ 84.949436] dwc2_pci_remove+0x1e/0x2c [dwc2_pci] [ 84.949440] pci_device_remove+0x31/0x81 [ 84.949445] device_release_driver_internal+0xea/0x18e [ 84.949448] driver_detach+0x68/0x72 [ 84.949450] bus_remove_driver+0x63/0x82 [ 84.949453] pci_unregister_driver+0x1a/0x75 [ 84.949457] __do_sys_delete_module+0x149/0x1e9 [ 84.949462] ? task_work_run+0x64/0x6e [ 84.949465] ? exit_to_user_mode_prepare+0xd4/0x10d [ 84.949471] do_syscall_64+0x5d/0x70 [ 84.949475] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 84.949480] RIP: 0033:0x7efdbd563bcb [ 84.949482] Code: 73 01 c3 48 8b 0d c5 82 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 95 82 0c 00 f7 d8 64 89 01 48 [ 84.949485] RSP: 002b:00007ffe944d7d98 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 [ 84.949489] RAX: ffffffffffffffda RBX: 00005651072eb700 RCX: 00007efdbd563bcb [ 84.949491] RDX: 000000000000000a RSI: 0000000000000800 RDI: 00005651072eb768 [ 84.949493] RBP: 00007ffe944d7df8 R08: 0000000000000000 R09: 0000000000000000 [ 84.949495] R10: 00007efdbd5dfac0 R11: 0000000000000206 R12: 00007ffe944d7fd0 [ 84.949497] R13: 00007ffe944d8610 R14: 00005651072eb2a0 R15: 00005651072eb700 [ 84.949500] Modules linked in: uas configfs dwc2_pci(-) phy_generic fuse crc32c_intel [last unloaded: udc_core] [ 84.949508] CR2: 00000007935688d8 [ 84.949510] ---[ end trace e40c871ca3e4dc9e ]--- [ 84.949512] RIP: 0010:usb_phy_uevent+0x99/0x121 Fixes: a8534cb092d7 ("usb: phy: introduce usb_phy device type with its own uevent handler") Signed-off-by: Artur Petrosyan Signed-off-by: Thinh Nguyen --- drivers/usb/phy/phy.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/phy/phy.c b/drivers/usb/phy/phy.c index 83ed5089475a..5046d4a07348 100644 --- a/drivers/usb/phy/phy.c +++ b/drivers/usb/phy/phy.c @@ -151,6 +151,9 @@ static int usb_phy_uevent(struct device *dev, struct kobj_uevent_env *env) char uchger_state[50] = { 0 }; char uchger_type[50] = { 0 }; + if (list_empty(&phy_list)) + return -ENODEV; + usb_phy = __device_to_usb_phy(dev); snprintf(uchger_state, ARRAY_SIZE(uchger_state), base-commit: 77d34a4683b053108ecd466cc7c4193b45805528 -- 2.25.1