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[23.128.96.18]) by mx.google.com with ESMTP id h9si835700edv.218.2021.04.26.15.08.46; Mon, 26 Apr 2021 15:09:09 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=WKjtzahp; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236016AbhDZWIU (ORCPT + 99 others); Mon, 26 Apr 2021 18:08:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36068 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232062AbhDZWIT (ORCPT ); Mon, 26 Apr 2021 18:08:19 -0400 Received: from mail-pg1-x52c.google.com (mail-pg1-x52c.google.com [IPv6:2607:f8b0:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BFA3AC061574 for ; Mon, 26 Apr 2021 15:07:36 -0700 (PDT) Received: by mail-pg1-x52c.google.com with SMTP id y32so40954046pga.11 for ; Mon, 26 Apr 2021 15:07:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=pDL7t8FU2ycRLM63Fb305VxNHvDCIUmpYtTkGnxHfEU=; b=WKjtzahpE31CTvaIFjlllnMG835QGD0aV65pi0H30EioGC20ZPbGWC09cHfS90lTAo axmkQRp0aJDVWzGdZ5xrbr0jc2i9XMrQgN214hGqpHAYpRwD2adBAlHaKkJeVlMQ8c76 FWlH1aB+cw0J9R9j0lQT8wK4pCLUD08wcIbbMma9y4B5LauxmEUMzTR7kddNzX9EQ/sG MNpIP6V1dgKixZybUJ1NeAzEHQw7PVyzudOss0I4CNhgwieZrRKBQxgKqrYzqKpPLsfY VxkABzh0zPy4xzDE8V29xAX6cA1+J0wEWb4Dl696GkvUKmeRLgb+Hnm1qEYGXC/5zEF9 IuLA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=pDL7t8FU2ycRLM63Fb305VxNHvDCIUmpYtTkGnxHfEU=; b=MrclRSokQIAm+fjmijEdgmoG/xzPgvCOk5X4jR8AkIcByTGnuDTR3oeWvr071zkLR3 VyMYSYKhuoNkAO45GjIx+6p3yaF3Z9ORV2ZGGl/BxVCMaSrzu8jg9yQEEM/xKVE55bhh IObnOK52E3p7qpRi9kn30UcNkhkq3MQ8Sx33ip66B1X+zZD88t0UPbCEM95/+8jE5o86 /BZLybDB4czjdJKvMgQrA+NandgI/M6wf43ZWCQ3EU0uop0/l8zXqr6YsJaM6L4mLrOF 7RPjhwRs0zYWFt5shBHf74CjNRLr5a7Yb0iP2XV1bIQ/IwV7TD1cPH6vyzZyTRFDT7Eg bqhA== X-Gm-Message-State: AOAM533SSHnOUs0CCSLEWE0oDHgwXqRB1rRM8Gmfdft3wFFzmu11ym4k hObjHWOMrG0+A5B9fTVRpW8= X-Received: by 2002:a62:6d05:0:b029:250:d196:1fc8 with SMTP id i5-20020a626d050000b0290250d1961fc8mr20116180pfc.21.1619474856254; Mon, 26 Apr 2021 15:07:36 -0700 (PDT) Received: from tong-desktop.local ([2601:647:4200:13:d478:1be:c725:5c32]) by smtp.googlemail.com with ESMTPSA id f3sm632071pjo.3.2021.04.26.15.07.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Apr 2021 15:07:35 -0700 (PDT) From: Tong Zhang To: Arnd Bergmann , Greg Kroah-Hartman , Tong Zhang , linux-kernel@vger.kernel.org Subject: [PATCH] misc: alcor_pci: fix null-ptr-deref when there is no PCI bridge Date: Mon, 26 Apr 2021 18:07:27 -0400 Message-Id: <20210426220728.1230340-1-ztong0001@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org the PCI bridge might be NULL, so we'd better check before use it [ 1.246492] BUG: kernel NULL pointer dereference, address: 00000000000000c0 [ 1.248731] RIP: 0010:pci_read_config_byte+0x5/0x40 [ 1.253998] Call Trace: [ 1.254131] ? alcor_pci_find_cap_offset.isra.0+0x3a/0x100 [alcor_pci] [ 1.254476] alcor_pci_probe+0x169/0x2d5 [alcor_pci] Signed-off-by: Tong Zhang --- drivers/misc/cardreader/alcor_pci.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/misc/cardreader/alcor_pci.c b/drivers/misc/cardreader/alcor_pci.c index cd402c89189e..1c33453fd5c7 100644 --- a/drivers/misc/cardreader/alcor_pci.c +++ b/drivers/misc/cardreader/alcor_pci.c @@ -102,6 +102,9 @@ static int alcor_pci_find_cap_offset(struct alcor_pci_priv *priv, u8 val8; u32 val32; + if (!pci) + return 0; + where = ALCOR_CAP_START_OFFSET; pci_read_config_byte(pci, where, &val8); if (!val8) -- 2.25.1