From patchwork Tue Apr 7 10:22:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 228159 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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 5E817C2BB1D for ; Tue, 7 Apr 2020 10:27:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2B61A2074B for ; Tue, 7 Apr 2020 10:27:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586255267; bh=TorpH4uEST+U3yxKOkCZL/m53n9xz2lDBNqCEdKUsyA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mx6NcCTDcadMS+l42ISIRhJoFy+ww/sGzSZmPOuKsW3sGvBazfXrgPgVVcFrxUHEK IlpTBc39LwEQzfTEPpyLt10Qg8VU5VQFjeceiNNGXsIxcN2D+Vg4k9IZnn6hKAuuyr UXgMs/WZu7pp2Zo7LEPswD+DUNodePPC+wWtmvxw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729190AbgDGK0k (ORCPT ); Tue, 7 Apr 2020 06:26:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:38828 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729187AbgDGK0i (ORCPT ); Tue, 7 Apr 2020 06:26:38 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6B79F2074F; Tue, 7 Apr 2020 10:26:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586255197; bh=TorpH4uEST+U3yxKOkCZL/m53n9xz2lDBNqCEdKUsyA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1jiPTpMzHDbG7C2TyPedRaBPxNc+MC9WjyHr1Q8mb3UC/FTp48MaFHFeG55FobEV9 PnmLpGdHZZKbIhA95b27iOCm5eHQXo+j1873zCvB7hTiLntcgvyVtH/NCZeieD7lta PSxLkwjWRyoQhbpshT46QFA/UY/v0F7J9xbMOq/w= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nicholas Johnson , Srinivas Kandagatla Subject: [PATCH 5.6 22/29] nvmem: check for NULL reg_read and reg_write before dereferencing Date: Tue, 7 Apr 2020 12:22:19 +0200 Message-Id: <20200407101454.761010846@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200407101452.046058399@linuxfoundation.org> References: <20200407101452.046058399@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Nicholas Johnson commit 3c91ef69a3e94f78546b246225ed573fbf1735b4 upstream. Return -EPERM if reg_read is NULL in bin_attr_nvmem_read() or if reg_write is NULL in bin_attr_nvmem_write(). This prevents NULL dereferences such as the one described in 03cd45d2e219 ("thunderbolt: Prevent crash if non-active NVMem file is read") Signed-off-by: Nicholas Johnson Cc: stable Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20200310132257.23358-10-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/nvmem/nvmem-sysfs.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/nvmem/nvmem-sysfs.c +++ b/drivers/nvmem/nvmem-sysfs.c @@ -56,6 +56,9 @@ static ssize_t bin_attr_nvmem_read(struc count = round_down(count, nvmem->word_size); + if (!nvmem->reg_read) + return -EPERM; + rc = nvmem->reg_read(nvmem->priv, pos, buf, count); if (rc) @@ -90,6 +93,9 @@ static ssize_t bin_attr_nvmem_write(stru count = round_down(count, nvmem->word_size); + if (!nvmem->reg_write) + return -EPERM; + rc = nvmem->reg_write(nvmem->priv, pos, buf, count); if (rc)