From patchwork Fri Sep 18 10:32:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Charan Teja Reddy X-Patchwork-Id: 67101 Received: from vger.kernel.org ([23.128.96.18]) by www.linuxtv.org with esmtp (Exim 4.92) (envelope-from ) id 1kJDg2-00EPgJ-LT; Fri, 18 Sep 2020 10:31:39 +0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726298AbgIRKhu (ORCPT + 1 other); Fri, 18 Sep 2020 06:37:50 -0400 Received: from so254-54.mailgun.net ([198.61.254.54]:23154 "EHLO so254-54.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725882AbgIRKhu (ORCPT ); Fri, 18 Sep 2020 06:37:50 -0400 X-Greylist: delayed 304 seconds by postgrey-1.27 at vger.kernel.org; Fri, 18 Sep 2020 06:37:49 EDT DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1600425470; h=Message-Id: Date: Subject: Cc: To: From: Sender; bh=qb2WoD3uf4Yfjw2dRwpjc0+G2WvhyNMin/XBmb+tRQ4=; b=IuHll3edWqs/gCibEznXYpdhZWqHzTk/QKdndMfTNnsFdsOf4FhwoZZ+u1DouSpVz3DhplbH NKpahd+tdgOnCz4kNej4hcABwb09gkIfrnlVhp1xadHJNtyl1FvqsAZ2WfuR/c+VpPlVUwK+ t/S2buIp3b1AouRaGKB9VbujGKE= X-Mailgun-Sending-Ip: 198.61.254.54 X-Mailgun-Sid: WyI3ZjU0NiIsICJsaW51eC1tZWRpYUB2Z2VyLmtlcm5lbC5vcmciLCAiYmU5ZTRhIl0= Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n04.prod.us-west-2.postgun.com with SMTP id 5f648ccdea858627d5e3c9dd (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Fri, 18 Sep 2020 10:32:45 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id EF4A1C43391; Fri, 18 Sep 2020 10:32:44 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-caf-mail-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=ALL_TRUSTED,BAYES_00,SPF_FAIL, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from charante-linux.qualcomm.com (unknown [202.46.22.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: charante) by smtp.codeaurora.org (Postfix) with ESMTPSA id 21028C43382; Fri, 18 Sep 2020 10:32:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 21028C43382 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=charante@codeaurora.org From: Charan Teja Reddy To: sumit.semwal@linaro.org, christian.koenig@amd.com, arnd@arndb.de Cc: linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org, vinmenon@codeaurora.org, Charan Teja Reddy , Subject: [PATCH] dmabuf: fix NULL pointer dereference in dma_buf_release() Date: Fri, 18 Sep 2020 16:02:31 +0530 Message-Id: <1600425151-27670-1-git-send-email-charante@codeaurora.org> X-Mailer: git-send-email 1.9.1 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-LSpam-Score: -2.3 (--) X-LSpam-Report: No, score=-2.3 required=5.0 tests=BAYES_00=-1.9,DKIM_SIGNED=0.1,HEADER_FROM_DIFFERENT_DOMAINS=0.5,MAILING_LIST_MULTI=-1,T_DKIM_INVALID=0.01 autolearn=ham autolearn_force=no NULL pointer dereference is observed while exporting the dmabuf but failed to allocate the 'struct file' which results into the dropping of the allocated dentry corresponding to this file in the dmabuf fs, which is ending up in dma_buf_release() and accessing the uninitialzed dentry->d_fsdata. Call stack on 5.4 is below: dma_buf_release+0x2c/0x254 drivers/dma-buf/dma-buf.c:88 __dentry_kill+0x294/0x31c fs/dcache.c:584 dentry_kill fs/dcache.c:673 [inline] dput+0x250/0x380 fs/dcache.c:859 path_put+0x24/0x40 fs/namei.c:485 alloc_file_pseudo+0x1a4/0x200 fs/file_table.c:235 dma_buf_getfile drivers/dma-buf/dma-buf.c:473 [inline] dma_buf_export+0x25c/0x3ec drivers/dma-buf/dma-buf.c:585 Fix this by checking for the valid pointer in the dentry->d_fsdata. Fixes: 4ab59c3c638c ("dma-buf: Move dma_buf_release() from fops to dentry_ops") Cc: [5.7+] Signed-off-by: Charan Teja Reddy Reviewed-by: Christian König --- drivers/dma-buf/dma-buf.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 58564d82..844967f 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -59,6 +59,8 @@ static void dma_buf_release(struct dentry *dentry) struct dma_buf *dmabuf; dmabuf = dentry->d_fsdata; + if (unlikely(!dmabuf)) + return; BUG_ON(dmabuf->vmapping_counter);