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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,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 E927BC433B4 for ; Tue, 27 Apr 2021 02:20:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A7FD7613AB for ; Tue, 27 Apr 2021 02:20:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235337AbhD0CVI (ORCPT ); Mon, 26 Apr 2021 22:21:08 -0400 Received: from relay5-d.mail.gandi.net ([217.70.183.197]:49497 "EHLO relay5-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232159AbhD0CVG (ORCPT ); Mon, 26 Apr 2021 22:21:06 -0400 X-Originating-IP: 68.203.5.165 Received: from tacos.lan (cpe-68-203-5-165.austin.res.rr.com [68.203.5.165]) (Authenticated sender: frank@zago.net) by relay5-d.mail.gandi.net (Postfix) with ESMTPSA id 165E71C0004; Tue, 27 Apr 2021 02:20:20 +0000 (UTC) From: Frank Zago To: Jonathan Cameron , Lars-Peter Clausen , Alexandru Ardelean , frank zago , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] iio: core: fix list breakage in iio_device_unregister() Date: Mon, 26 Apr 2021 21:20:16 -0500 Message-Id: <20210427022017.19314-1-frank@zago.net> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: frank zago The ioctl handlers are unlinked and freed in iio_buffers_free_sysfs_and_mask(). Do not break the list prematurely. This fixes the following GPF when a client module is removed: [ 157.007865] general protection fault, probably for non-canonical address 0xdead000000000100: 0000 [#1] SMP NOPTI [ 157.007876] CPU: 6 PID: 2353 Comm: rmmod Not tainted 5.12.0+ #29 [ 157.007882] ... [ 157.007886] RIP: 0010:iio_device_ioctl_handler_unregister+0xd/0x30 [industrialio] [ 157.007904] Code: 00 48 89 77 08 48 89 3e 48 89 e5 48 89 46 08 48 89 30 5d c3 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 8b 47 08 48 8b 17 55 <48> 89 42 08 48 89 10 48 89 e5 48 b8 00 01 00 00 00 00 ad de 5d 48 [ 157.007910] RSP: 0018:ffffa9b840a57d70 EFLAGS: 00010202 [ 157.007916] RAX: dead000000000122 RBX: ffff95484e9a8000 RCX: 0000000000000000 [ 157.007920] RDX: dead000000000100 RSI: 0000000000000246 RDI: ffff9548489a2360 [ 157.007923] RBP: ffffa9b840a57da0 R08: 0000000000000000 R09: ffffa9b840a57d18 [ 157.007926] R10: 0000000000000000 R11: ffff95489f3e5180 R12: ffff95484e9a8000 [ 157.007929] R13: ffff95484e9a8390 R14: ffff95484e9a8000 R15: 0000000000000000 [ 157.007933] FS: 00007fd35bd18540(0000) GS:ffff954b4eb80000(0000) knlGS:0000000000000000 [ 157.007937] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 157.007941] CR2: 000055e1e29d4818 CR3: 000000010ae76000 CR4: 00000000003506e0 [ 157.007945] Call Trace: [ 157.007950] ? iio_buffers_free_sysfs_and_mask+0x2a/0xb0 [industrialio] [ 157.007965] iio_device_unregister+0xba/0xc0 [industrialio] [ 157.007978] tcs3472_remove+0x1e/0x90 [tcs3472] [ 157.007984] i2c_device_remove+0x2b/0xa0 [ 157.007993] __device_release_driver+0x181/0x240 [ 157.008000] driver_detach+0xd5/0x120 [ 157.008005] bus_remove_driver+0x5c/0xe0 [ 157.008010] driver_unregister+0x31/0x50 [ 157.008014] i2c_del_driver+0x46/0x70 [ 157.008020] tcs3472_driver_exit+0x10/0x5dd [tcs3472] [ 157.008026] __do_sys_delete_module.constprop.0+0x183/0x290 [ 157.008033] ? exit_to_user_mode_prepare+0x37/0x1c0 [ 157.008041] __x64_sys_delete_module+0x12/0x20 [ 157.008045] do_syscall_64+0x40/0xb0 [ 157.008052] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 157.008058] RIP: 0033:0x7fd35be5aceb [ 157.008063] Code: 73 01 c3 48 8b 0d 7d 91 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 4d 91 0c 00 f7 d8 64 89 01 48 [ 157.008068] RSP: 002b:00007ffe90b07478 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 [ 157.008073] RAX: ffffffffffffffda RBX: 000055e1e29ca770 RCX: 00007fd35be5aceb [ 157.008076] RDX: 000000000000000a RSI: 0000000000000800 RDI: 000055e1e29ca7d8 [ 157.008079] RBP: 00007ffe90b074d8 R08: 0000000000000000 R09: 0000000000000000 [ 157.008081] R10: 00007fd35bed5ac0 R11: 0000000000000206 R12: 00007ffe90b076b0 [ 157.008084] R13: 00007ffe90b08807 R14: 000055e1e29ca2a0 R15: 000055e1e29ca770 [ 157.008089] Modules linked in: tcs3472(-) industrialio_triggered_buffer kfifo_buf industrialio ch341_buses binfmt_misc snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio snd_hda_codec_hdmi snd_hda_intel snd_intel_dspcfg snd_hda_codec snd_hwdep snd_hda_core snd_pcm wmi_bmof snd_seq snd_timer snd_seq_device input_leds rapl snd ccp k10temp soundcore wmi mac_hid sch_fq_codel parport_pc ppdev lp parport ip_tables x_tables autofs4 dm_crypt hid_generic usbhid hid radeon i2c_algo_bit drm_ttm_helper ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec rc_core drm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel r8169 crypto_simd cryptd ahci i2c_piix4 xhci_pci realtek libahci xhci_pci_renesas gpio_amdpt gpio_generic [last unloaded: tcs3472] [ 157.008167] ---[ end trace c8eef7a3c5a40ff0 ]--- Signed-off-by: frank zago --- drivers/iio/industrialio-core.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index d92c58a94fe4..9e59f5da3d28 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -1926,9 +1926,6 @@ EXPORT_SYMBOL(__iio_device_register); **/ void iio_device_unregister(struct iio_dev *indio_dev) { - struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); - struct iio_ioctl_handler *h, *t; - cdev_device_del(&indio_dev->chrdev, &indio_dev->dev); mutex_lock(&indio_dev->info_exist_lock); @@ -1939,9 +1936,6 @@ void iio_device_unregister(struct iio_dev *indio_dev) indio_dev->info = NULL; - list_for_each_entry_safe(h, t, &iio_dev_opaque->ioctl_handlers, entry) - list_del(&h->entry); - iio_device_wakeup_eventset(indio_dev); iio_buffer_wakeup_poll(indio_dev); -- 2.27.0