From patchwork Fri Feb 5 14:06:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 378068 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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 94E69C433DB for ; Fri, 5 Feb 2021 21:20:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5491464FB9 for ; Fri, 5 Feb 2021 21:20:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233730AbhBEVUn (ORCPT ); Fri, 5 Feb 2021 16:20:43 -0500 Received: from mail.kernel.org ([198.145.29.99]:45584 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233052AbhBEPCQ (ORCPT ); Fri, 5 Feb 2021 10:02:16 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9B53265034; Fri, 5 Feb 2021 14:11:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612534299; bh=qMW7ue19Uwp7HdV1n3mt6+nPLKC9zLXPVm9Mhou7CTo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yyzeFbEu51aqJ4/FPbdMWCXfQP3Fptu63cvSqXpdDLjTJ9qIGJZxYLT0TRyj8XO8D fgDFcfl10kT4EtzHyavtcJYwS4HD+eU2vCOO43RO6R50KE+/dfUn8qL4du1sQtJLP3 VqO3iRA8Gj4NGJfBJMlDa1lpTfOYJs5PAqzRI+aA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sujuan Chen , Ryder Lee , Shayne Chen , Johannes Berg , Sasha Levin Subject: [PATCH 5.10 32/57] mac80211: fix incorrect strlen of .write in debugfs Date: Fri, 5 Feb 2021 15:06:58 +0100 Message-Id: <20210205140657.342648190@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210205140655.982616732@linuxfoundation.org> References: <20210205140655.982616732@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Shayne Chen [ Upstream commit 6020d534fa012b80c6d13811dc4d2dfedca2e403 ] This fixes strlen mismatch problems happening in some .write callbacks of debugfs. When trying to configure airtime_flags in debugfs, an error appeared: ash: write error: Invalid argument The error is returned from kstrtou16() since a wrong length makes it miss the real end of input string. To fix this, use count as the string length, and set proper end of string for a char buffer. The debug print is shown - airtime_flags_write: count = 2, len = 8, where the actual length is 2, but "len = strlen(buf)" gets 8. Also cleanup the other similar cases for the sake of consistency. Signed-off-by: Sujuan Chen Signed-off-by: Ryder Lee Signed-off-by: Shayne Chen Link: https://lore.kernel.org/r/20210112032028.7482-1-shayne.chen@mediatek.com Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- net/mac80211/debugfs.c | 44 +++++++++++++++++++----------------------- 1 file changed, 20 insertions(+), 24 deletions(-) diff --git a/net/mac80211/debugfs.c b/net/mac80211/debugfs.c index 90470392fdaa7..de5cd3818690c 100644 --- a/net/mac80211/debugfs.c +++ b/net/mac80211/debugfs.c @@ -120,18 +120,17 @@ static ssize_t aqm_write(struct file *file, { struct ieee80211_local *local = file->private_data; char buf[100]; - size_t len; - if (count > sizeof(buf)) + if (count >= sizeof(buf)) return -EINVAL; if (copy_from_user(buf, user_buf, count)) return -EFAULT; - buf[sizeof(buf) - 1] = '\0'; - len = strlen(buf); - if (len > 0 && buf[len-1] == '\n') - buf[len-1] = 0; + if (count && buf[count - 1] == '\n') + buf[count - 1] = '\0'; + else + buf[count] = '\0'; if (sscanf(buf, "fq_limit %u", &local->fq.limit) == 1) return count; @@ -177,18 +176,17 @@ static ssize_t airtime_flags_write(struct file *file, { struct ieee80211_local *local = file->private_data; char buf[16]; - size_t len; - if (count > sizeof(buf)) + if (count >= sizeof(buf)) return -EINVAL; if (copy_from_user(buf, user_buf, count)) return -EFAULT; - buf[sizeof(buf) - 1] = 0; - len = strlen(buf); - if (len > 0 && buf[len - 1] == '\n') - buf[len - 1] = 0; + if (count && buf[count - 1] == '\n') + buf[count - 1] = '\0'; + else + buf[count] = '\0'; if (kstrtou16(buf, 0, &local->airtime_flags)) return -EINVAL; @@ -237,20 +235,19 @@ static ssize_t aql_txq_limit_write(struct file *file, { struct ieee80211_local *local = file->private_data; char buf[100]; - size_t len; u32 ac, q_limit_low, q_limit_high, q_limit_low_old, q_limit_high_old; struct sta_info *sta; - if (count > sizeof(buf)) + if (count >= sizeof(buf)) return -EINVAL; if (copy_from_user(buf, user_buf, count)) return -EFAULT; - buf[sizeof(buf) - 1] = 0; - len = strlen(buf); - if (len > 0 && buf[len - 1] == '\n') - buf[len - 1] = 0; + if (count && buf[count - 1] == '\n') + buf[count - 1] = '\0'; + else + buf[count] = '\0'; if (sscanf(buf, "%u %u %u", &ac, &q_limit_low, &q_limit_high) != 3) return -EINVAL; @@ -306,18 +303,17 @@ static ssize_t force_tx_status_write(struct file *file, { struct ieee80211_local *local = file->private_data; char buf[3]; - size_t len; - if (count > sizeof(buf)) + if (count >= sizeof(buf)) return -EINVAL; if (copy_from_user(buf, user_buf, count)) return -EFAULT; - buf[sizeof(buf) - 1] = '\0'; - len = strlen(buf); - if (len > 0 && buf[len - 1] == '\n') - buf[len - 1] = 0; + if (count && buf[count - 1] == '\n') + buf[count - 1] = '\0'; + else + buf[count] = '\0'; if (buf[0] == '0' && buf[1] == '\0') local->force_tx_status = 0;