From patchwork Thu Jun 3 13:33:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zheyu Ma X-Patchwork-Id: 454423 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham 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 89E4DC47082 for ; Thu, 3 Jun 2021 13:34:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6C297613E3 for ; Thu, 3 Jun 2021 13:34:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230092AbhFCNft (ORCPT ); Thu, 3 Jun 2021 09:35:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59798 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230056AbhFCNfs (ORCPT ); Thu, 3 Jun 2021 09:35:48 -0400 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 724EFC06174A; Thu, 3 Jun 2021 06:33:49 -0700 (PDT) Received: by mail-pf1-x435.google.com with SMTP id q25so4884008pfh.7; Thu, 03 Jun 2021 06:33:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=ctsfVI/vZCq/FOh8pV2IxR33N4F11DLsoUQif+z3UzE=; b=hY2sbz7eOOPEGtagTymBW5uROJEgCZ8/Fu02Xv3WqalSrRXwNE0RtDjBIC6hbkMINr KoljsG47j0/Hzc0YeS7yBtOBmXrF2yn4Ybr6ZKHt+GDENeh6yPx9qK0ntJccyuTkLsAd 0CjfEUcKp3xwuNYL12Zhr7CE7GU5ByZVeXYj90u+fZ2uLOz0QkLXaMZrzic+N2Oo/Fqk WB6E3KNi8s6X6L/0N5OUmShsAO6Xygk71K5l8UyFMjMVfacrMFtdi4UGsiwfAf+nd6L2 S9fvDX6VG8F36x8iEFlWKdCNQCcN1Hu8jK/fZ/2dIPJ0veOfl0JJeeaKIwT6UBy/4uB5 rkTQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=ctsfVI/vZCq/FOh8pV2IxR33N4F11DLsoUQif+z3UzE=; b=n1RvLOmyWYmQFFRanNcXRAzOSbYDcvLIywHMin0iY7NuXJbtbp+wfEePfFDCmVFyhE 8Tu3mUweI+jvuKa9/bult9FWuj0i3010gS3xRdbZteuaE+h8dwJurAKU6YVBIQuf5s+Q aGJU9fr8GCLyOX1a1pkYNKzmwfKJyS9YrvKMT4CzX6vD1Umnwr9QZ86Tz3Ps+vzO4UnY D4uTQ3kHWud32yHcMF/8IIJPoCNa9MKwOCYvxZHkt8zUeBoIXKaEZfi1QrfgP/TeJd58 oVZSdL+zNOwio7bhLHC7uKJrBd1IBgdMDziCf6K5Q0BtPPP7DOE9Sn/YJ7ahWF2XWBtZ 9qRw== X-Gm-Message-State: AOAM5302kT78CDPzbtpHRoATugcW24PjBja2OgWYW/qQ1usSBC2xuLWy FA5gb8S7R/n2rW5xDRd2pA== X-Google-Smtp-Source: ABdhPJwAhMwMeJNlqE9O9VHJRgIXWaYCOkvO4H+RrsgOUacLLhSTmalEb9W7S0xUdEohB/cACCwSHA== X-Received: by 2002:a05:6a00:856:b029:2dc:bd34:9f7e with SMTP id q22-20020a056a000856b02902dcbd349f7emr33046158pfk.0.1622727228947; Thu, 03 Jun 2021 06:33:48 -0700 (PDT) Received: from vultr.guest ([107.191.53.97]) by smtp.gmail.com with ESMTPSA id o133sm2476302pfd.49.2021.06.03.06.33.46 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 03 Jun 2021 06:33:48 -0700 (PDT) From: Zheyu Ma To: brucechang@via.com.tw, HaraldWelte@viatech.com, ulf.hansson@linaro.org Cc: linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, Zheyu Ma Subject: [PATCH] mmc: via-sdmmc: add a check against NULL pointer dereference Date: Thu, 3 Jun 2021 13:33:20 +0000 Message-Id: <1622727200-15808-1-git-send-email-zheyuma97@gmail.com> X-Mailer: git-send-email 2.7.4 Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org Before referencing 'host->data', the driver needs to check whether it is null pointer, otherwise it will cause a null pointer reference. This log reveals it: [ 29.355199] BUG: kernel NULL pointer dereference, address: 0000000000000014 [ 29.357323] #PF: supervisor write access in kernel mode [ 29.357706] #PF: error_code(0x0002) - not-present page [ 29.358088] PGD 0 P4D 0 [ 29.358280] Oops: 0002 [#1] PREEMPT SMP PTI [ 29.358595] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.12.4- g70e7f0549188-dirty #102 [ 29.359164] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 [ 29.359978] RIP: 0010:via_sdc_isr+0x21f/0x410 [ 29.360314] Code: ff ff e8 84 aa d0 fd 66 45 89 7e 28 66 41 f7 c4 00 10 75 56 e8 72 aa d0 fd 66 41 f7 c4 00 c0 74 10 e8 65 aa d0 fd 48 8b 43 18 40 14 ac ff ff ff e8 55 aa d0 fd 48 89 df e8 ad fb ff ff e9 77 [ 29.361661] RSP: 0018:ffffc90000118e98 EFLAGS: 00010046 [ 29.362042] RAX: 0000000000000000 RBX: ffff888107d77880 RCX: 0000000000000000 [ 29.362564] RDX: 0000000000000000 RSI: ffffffff835d20bb RDI: 00000000ffffffff [ 29.363085] RBP: ffffc90000118ed8 R08: 0000000000000001 R09: 0000000000000001 [ 29.363604] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000008600 [ 29.364128] R13: ffff888107d779c8 R14: ffffc90009c00200 R15: 0000000000008000 [ 29.364651] FS: 0000000000000000(0000) GS:ffff88817bc80000(0000) knlGS:0000000000000000 [ 29.365235] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 29.365655] CR2: 0000000000000014 CR3: 0000000005a2e000 CR4: 00000000000006e0 [ 29.366170] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.366683] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.367197] Call Trace: [ 29.367381] [ 29.367537] __handle_irq_event_percpu+0x53/0x3e0 [ 29.367916] handle_irq_event_percpu+0x35/0x90 [ 29.368247] handle_irq_event+0x39/0x60 [ 29.368632] handle_fasteoi_irq+0xc2/0x1d0 [ 29.368950] __common_interrupt+0x7f/0x150 [ 29.369254] common_interrupt+0xb4/0xd0 [ 29.369547] [ 29.369708] asm_common_interrupt+0x1e/0x40 [ 29.370016] RIP: 0010:native_safe_halt+0x17/0x20 [ 29.370360] Code: 07 0f 00 2d db 80 43 00 f4 5d c3 0f 1f 84 00 00 00 00 00 8b 05 c2 37 e5 01 55 48 89 e5 85 c0 7e 07 0f 00 2d bb 80 43 00 fb f4 <5d> c3 cc cc cc cc cc cc cc 55 48 89 e5 e8 67 53 ff ff 8b 0d f9 91 [ 29.371696] RSP: 0018:ffffc9000008fe90 EFLAGS: 00000246 [ 29.372079] RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000000 [ 29.372595] RDX: 0000000000000000 RSI: ffffffff854f67a4 RDI: ffffffff85403406 [ 29.373122] RBP: ffffc9000008fe90 R08: 0000000000000001 R09: 0000000000000001 [ 29.373646] R10: 0000000000000000 R11: 0000000000000001 R12: ffffffff86009188 [ 29.374160] R13: 0000000000000000 R14: 0000000000000000 R15: ffff888100258000 [ 29.374690] default_idle+0x9/0x10 [ 29.374944] arch_cpu_idle+0xa/0x10 [ 29.375198] default_idle_call+0x6e/0x250 [ 29.375491] do_idle+0x1f0/0x2d0 [ 29.375740] cpu_startup_entry+0x18/0x20 [ 29.376034] start_secondary+0x11f/0x160 [ 29.376328] secondary_startup_64_no_verify+0xb0/0xbb [ 29.376705] Modules linked in: [ 29.376939] Dumping ftrace buffer: [ 29.377187] (ftrace buffer empty) [ 29.377460] CR2: 0000000000000014 [ 29.377712] ---[ end trace 51a473dffb618c47 ]--- [ 29.378056] RIP: 0010:via_sdc_isr+0x21f/0x410 [ 29.378380] Code: ff ff e8 84 aa d0 fd 66 45 89 7e 28 66 41 f7 c4 00 10 75 56 e8 72 aa d0 fd 66 41 f7 c4 00 c0 74 10 e8 65 aa d0 fd 48 8b 43 18 40 14 ac ff ff ff e8 55 aa d0 fd 48 89 df e8 ad fb ff ff e9 77 [ 29.379714] RSP: 0018:ffffc90000118e98 EFLAGS: 00010046 [ 29.380098] RAX: 0000000000000000 RBX: ffff888107d77880 RCX: 0000000000000000 [ 29.380614] RDX: 0000000000000000 RSI: ffffffff835d20bb RDI: 00000000ffffffff [ 29.381134] RBP: ffffc90000118ed8 R08: 0000000000000001 R09: 0000000000000001 [ 29.381653] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000008600 [ 29.382176] R13: ffff888107d779c8 R14: ffffc90009c00200 R15: 0000000000008000 [ 29.382697] FS: 0000000000000000(0000) GS:ffff88817bc80000(0000) knlGS:0000000000000000 [ 29.383277] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 29.383697] CR2: 0000000000000014 CR3: 0000000005a2e000 CR4: 00000000000006e0 [ 29.384223] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.384736] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.385260] Kernel panic - not syncing: Fatal exception in interrupt [ 29.385882] Dumping ftrace buffer: [ 29.386135] (ftrace buffer empty) [ 29.386401] Kernel Offset: disabled [ 29.386656] Rebooting in 1 seconds.. Signed-off-by: Zheyu Ma --- drivers/mmc/host/via-sdmmc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/mmc/host/via-sdmmc.c b/drivers/mmc/host/via-sdmmc.c index a1d098560099..c32df5530b94 100644 --- a/drivers/mmc/host/via-sdmmc.c +++ b/drivers/mmc/host/via-sdmmc.c @@ -857,6 +857,9 @@ static void via_sdc_data_isr(struct via_crdr_mmc_host *host, u16 intmask) { BUG_ON(intmask == 0); + if (!host->data) + return; + if (intmask & VIA_CRDR_SDSTS_DT) host->data->error = -ETIMEDOUT; else if (intmask & (VIA_CRDR_SDSTS_RC | VIA_CRDR_SDSTS_WC))