From nobody Fri Feb 13 14:10:34 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7AF1ACE7A8A for ; Sun, 24 Sep 2023 19:51:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230029AbjIXTvL (ORCPT ); Sun, 24 Sep 2023 15:51:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45946 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231459AbjIXTvH (ORCPT ); Sun, 24 Sep 2023 15:51:07 -0400 Received: from mail-wm1-x336.google.com (mail-wm1-x336.google.com [IPv6:2a00:1450:4864:20::336]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADF5D193 for ; Sun, 24 Sep 2023 12:50:59 -0700 (PDT) Received: by mail-wm1-x336.google.com with SMTP id 5b1f17b1804b1-4051d33af1fso16243905e9.0 for ; Sun, 24 Sep 2023 12:50:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1695585058; x=1696189858; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=fgyKxqKA15nbfaH4vMDu01hflBvGs/eg6IGSdQy6Jmg=; b=YICS9s8cGplPci++Do1NpU+EWsUwFr37i+tcskMiZqQ8CzHTfXjWSABODQKyI9mfqB xxpnqt11FtmcA2Uq5KPE8QxDSJ5qlHtv3nFrtv79DLZWOqqipIcoafFTgpRHvQahA2sy l4+EIOC0z4F7C3fd6rKEuy7fJDLCC1+wXFFXwgL54lXdyHQqz8UfOJjLtmCmIWiKluOQ Z0NnL9fLZMSAdDx3qjCKIamJwDisu2lNt1PnIiPah/SfkRrYX5E6+OGwwryh22bbv4qE Q0EM72Y5cSQmG80Uf+PLuMYLN7gT4mZVaU1v80zqlb1wy6e2JfrFc6q+QsN1GvXAsyMY Z2SQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695585058; x=1696189858; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=fgyKxqKA15nbfaH4vMDu01hflBvGs/eg6IGSdQy6Jmg=; b=V9JOC9N0xIaNqV8Lg+L3rZFlVBPH1dysZsgvEdIrskalKi3R6H7YGPQhIuC/wxdzSM VnJNdKOzOdaFk409GgVIHPUHSUK6SWVmovbTXm/hhruLM32IdB5DRxffANci5Gnp3cHi rsQhcpgYN+s/yZ2Bjy1BLTx3iZbzWM+1aEvyJp52K6/irtmQiiANF9YeKd3dbSn1G4rN coLM2gMz8dIF1TOwZQdMm+bhbkuTm34RyZ3roiq7CaB3mvRCKFlFeyds8jLCPKCUntWp mS/Nl2oaT7qHfh8cxDOydEwXV4eWiio2CFmq/C6f+I7WB3oGo4UxOwfW8ibVvpXYMKX1 /YUQ== X-Gm-Message-State: AOJu0Yz5rHNsvoxGu73F+ph4/LEreZYL1JBxEnCtzziD431LGb8p8rQB X/cM6xIbh2vFi6yb1b19M0Y= X-Google-Smtp-Source: AGHT+IF4ubKUcoW7XeHwG8rJ5kor+/5lTlxu9UUKJEk1dt+QSmfibbPJjVlYjeYfpDhqKv+ebMkVjA== X-Received: by 2002:a05:600c:3223:b0:3fe:d46a:ef4b with SMTP id r35-20020a05600c322300b003fed46aef4bmr4053775wmp.1.1695585057685; Sun, 24 Sep 2023 12:50:57 -0700 (PDT) Received: from matrix-ESPRIMO-P710 (p579356c7.dip0.t-ipconnect.de. [87.147.86.199]) by smtp.gmail.com with ESMTPSA id s17-20020a1cf211000000b003fe2a40d287sm10339959wmc.1.2023.09.24.12.50.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 24 Sep 2023 12:50:57 -0700 (PDT) Date: Sun, 24 Sep 2023 21:50:55 +0200 From: Philipp Hortmann To: Greg Kroah-Hartman , linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH 2/4] staging: rtl8192e: Remove mutex from rtllib_softmac_free() Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The following commands use the mutex ieee->wx_mutex: cancel_delayed_work_sync(&ieee->associate_retry_wq) cancel_delayed_work_sync(&ieee->associate_procedure_wq) cancel_work_sync(&ieee->wx_sync_scan_wq) Therefore they cannot be canceled with ieee->wx_mutex locked. As the work functions are executed time shifted during normal operation of the driver, proper locking can only be done inside the functions. Signed-off-by: Philipp Hortmann --- Tested with rtl8192e (WLL6130-D99) in Mode n (12.5 MB/s) Transferred this patch over wlan connection of rtl8192e. [ 261.339100] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D [ 261.339102] WARNING: possible circular locking dependency detected [ 261.339103] 6.6.0-rc1+ #15 Tainted: G C OE [ 261.339105] ------------------------------------------------------ [ 261.339106] rmmod/6566 is trying to acquire lock: [ 261.339109] ffff888113ca8800 ((work_completion)(&(&ieee->associate_proce= dure_wq)->work)){+.+.}-{0:0}, at: __flush_work+0x4d/0x490 [ 261.339118] but task is already holding lock: [ 261.339119] ffff888113ca7aa0 (&ieee->wx_mutex){+.+.}-{4:4}, at: rtllib_s= oftmac_free+0x20/0xd0 [rtllib] [ 261.339134] which lock already depends on the new lock. [ 261.339136] the existing dependency chain (in reverse order) is: [ 261.339137] -> #1 (&ieee->wx_mutex){+.+.}-{4:4}: [ 261.339140] __mutex_lock+0x99/0xce0 [ 261.339146] mutex_lock_nested+0x1b/0x30 [ 261.339149] rtllib_associate_procedure_wq+0x5b/0x4b0 [rtllib] [ 261.339159] process_scheduled_works+0x308/0x580 [ 261.339161] worker_thread+0x19b/0x360 [ 261.339163] kthread+0x116/0x150 [ 261.339166] ret_from_fork+0x3c/0x60 [ 261.339170] ret_from_fork_asm+0x1b/0x30 [ 261.339174] -> #0 ((work_completion)(&(&ieee->associate_procedure_wq)->w= ork)){+.+.}-{0:0}: [ 261.339177] __lock_acquire+0x12e0/0x1de0 [ 261.339182] lock_acquire+0xdc/0x2c0 [ 261.339185] __flush_work+0x6d/0x490 [ 261.339187] __cancel_work_timer+0x137/0x1c0 [ 261.339190] cancel_delayed_work_sync+0x13/0x20 [ 261.339192] rtllib_softmac_free+0x5b/0xd0 [rtllib] [ 261.339201] free_rtllib+0x27/0x70 [rtllib] [ 261.339209] _rtl92e_pci_disconnect+0xaf/0x140 [r8192e_pci] [ 261.339217] pci_device_remove+0x39/0xb0 [ 261.339221] device_remove+0x46/0x70 [ 261.339225] device_release_driver_internal+0xb9/0x140 [ 261.339228] driver_detach+0x4d/0xa0 [ 261.339231] bus_remove_driver+0x6e/0xf0 [ 261.339233] driver_unregister+0x31/0x50 [ 261.339236] pci_unregister_driver+0x40/0x90 [ 261.339239] rtl8192_pci_driver_exit+0x10/0x380 [r8192e_pci] [ 261.339247] __do_sys_delete_module.isra.0+0x187/0x2f0 [ 261.339251] __x64_sys_delete_module+0x12/0x20 [ 261.339254] do_syscall_64+0x3b/0x90 [ 261.339257] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 [ 261.339261] other info that might help us debug this: [ 261.339262] Possible unsafe locking scenario: [ 261.339263] CPU0 CPU1 [ 261.339264] ---- ---- [ 261.339265] lock(&ieee->wx_mutex); [ 261.339268] lock((work_completion)(&(&iee= e->associate_procedure_wq)->work)); [ 261.339270] lock(&ieee->wx_mutex); [ 261.339272] lock((work_completion)(&(&ieee->associate_procedure_wq)->w= ork)); [ 261.339274] *** DEADLOCK *** [ 261.339275] 2 locks held by rmmod/6566: [ 261.339277] #0: ffff8881015d51b0 (&dev->mutex){....}-{4:4}, at: __devic= e_driver_lock+0x2d/0x50 [ 261.339283] #1: ffff888113ca7aa0 (&ieee->wx_mutex){+.+.}-{4:4}, at: rtl= lib_softmac_free+0x20/0xd0 [rtllib] [ 261.339295] stack backtrace: [ 261.339296] CPU: 1 PID: 6566 Comm: rmmod Tainted: G C OE 6.= 6.0-rc1+ #15 [ 261.339299] Hardware name: FUJITSU ESPRIMO P710/D3161-A1, BIOS V4.6.5.3 = R1.16.0 for D3161-A1x 10/29/2012 [ 261.339301] Call Trace: [ 261.339302] [ 261.339304] dump_stack_lvl+0x5c/0xa0 [ 261.339309] dump_stack+0x10/0x20 [ 261.339311] print_circular_bug.isra.0+0x300/0x440 [ 261.339316] check_noncircular+0x136/0x150 [ 261.339319] ? register_lock_class+0x4c/0x460 [ 261.339322] ? __bfs+0x110/0x250 [ 261.339326] __lock_acquire+0x12e0/0x1de0 [ 261.339330] ? hugetlb_init+0x5b2/0x720 [ 261.339335] lock_acquire+0xdc/0x2c0 [ 261.339339] ? __flush_work+0x4d/0x490 [ 261.339342] ? __this_cpu_preempt_check+0x13/0x20 [ 261.339345] ? lock_release+0x14f/0x380 [ 261.339349] __flush_work+0x6d/0x490 [ 261.339352] ? __flush_work+0x4d/0x490 [ 261.339354] ? lock_timer_base+0x72/0xa0 [ 261.339357] ? __this_cpu_preempt_check+0x13/0x20 [ 261.339359] ? lock_acquired+0xef/0x3b0 [ 261.339362] ? sched_clock_noinstr+0x9/0x10 [ 261.339367] ? __cancel_work_timer+0x10d/0x1c0 [ 261.339369] ? __this_cpu_preempt_check+0x13/0x20 [ 261.339373] __cancel_work_timer+0x137/0x1c0 [ 261.339377] cancel_delayed_work_sync+0x13/0x20 [ 261.339380] rtllib_softmac_free+0x5b/0xd0 [rtllib] [ 261.339389] free_rtllib+0x27/0x70 [rtllib] [ 261.339397] _rtl92e_pci_disconnect+0xaf/0x140 [r8192e_pci] [ 261.339406] pci_device_remove+0x39/0xb0 [ 261.339410] device_remove+0x46/0x70 [ 261.339413] device_release_driver_internal+0xb9/0x140 [ 261.339417] driver_detach+0x4d/0xa0 [ 261.339420] bus_remove_driver+0x6e/0xf0 [ 261.339424] driver_unregister+0x31/0x50 [ 261.339427] pci_unregister_driver+0x40/0x90 [ 261.339431] rtl8192_pci_driver_exit+0x10/0x380 [r8192e_pci] [ 261.339439] __do_sys_delete_module.isra.0+0x187/0x2f0 [ 261.339442] ? syscall_enter_from_user_mode+0x21/0x60 [ 261.339446] ? lockdep_hardirqs_on+0x86/0x110 [ 261.339450] __x64_sys_delete_module+0x12/0x20 [ 261.339454] do_syscall_64+0x3b/0x90 [ 261.339457] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 [ 261.339461] RIP: 0033:0x7f3b2132da6b [ 261.339464] Code: 73 01 c3 48 8b 0d 25 c4 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 f5 c3 0c 00 f7 d8 64 89 01 48 [ 261.339466] RSP: 002b:00007ffea140e858 EFLAGS: 00000206 ORIG_RAX: 000000= 00000000b0 [ 261.339469] RAX: ffffffffffffffda RBX: 00005637c0086770 RCX: 00007f3b213= 2da6b [ 261.339471] RDX: 000000000000000a RSI: 0000000000000800 RDI: 00005637c00= 867d8 [ 261.339473] RBP: 00007ffea140e8b8 R08: 0000000000000000 R09: 00000000000= 00000 [ 261.339474] R10: 00007f3b213a9ac0 R11: 0000000000000206 R12: 00007ffea14= 0ea90 [ 261.339476] R13: 00007ffea140f7c0 R14: 00005637c00862a0 R15: 00005637c00= 86770 [ 261.339480] --- drivers/staging/rtl8192e/rtllib_softmac.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/staging/rtl8192e/rtllib_softmac.c b/drivers/staging/rt= l8192e/rtllib_softmac.c index d3468b646ca8..c874468d075c 100644 --- a/drivers/staging/rtl8192e/rtllib_softmac.c +++ b/drivers/staging/rtl8192e/rtllib_softmac.c @@ -2461,7 +2461,6 @@ int rtllib_softmac_init(struct rtllib_device *ieee) =20 void rtllib_softmac_free(struct rtllib_device *ieee) { - mutex_lock(&ieee->wx_mutex); del_timer_sync(&ieee->associate_timer); =20 cancel_delayed_work_sync(&ieee->associate_retry_wq); @@ -2477,7 +2476,6 @@ void rtllib_softmac_free(struct rtllib_device *ieee) =20 kfree(ieee->dot11d_info); ieee->dot11d_info =3D NULL; - mutex_unlock(&ieee->wx_mutex); } =20 static inline struct sk_buff * --=20 2.42.0