From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D628CA0EEB for ; Tue, 12 Sep 2023 15:07:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236183AbjILPHc (ORCPT ); Tue, 12 Sep 2023 11:07:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55248 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236207AbjILPHV (ORCPT ); Tue, 12 Sep 2023 11:07:21 -0400 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1DC4A10DC for ; Tue, 12 Sep 2023 08:07:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1694531234; x=1726067234; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=W3PADM1uFv8tnSLMvvhvYaZtPehE/6YKdLW1n09TF9U=; b=Vv4fQh649KrhtEOhWDDiluxQ0RQ9PNd5alaPppENkXKbD5RwjbUW6LX5 tId8+i2o4KaYVtfD3oYpWalvJzIUiTzlU5iX18fOeCj39c2RtXxyii1yc TB+idrCJ5iDf24Tp1ha7Gjchx+xzVP+r1q7i7TMIYPJNuF7MwlQIXnjov BwrTXE4IS37O4sia6xq7tVL9Mkm4KW445hem7DAQxwNTxXLJ/G9TacbHQ u4BzCK7JpVhxDFANvni7wK4ekhO6v7KNqWVF094Z4cMjTuum3/xpvKQ+f c7atHFUsAcgvONPiaRu4XkfKqv4DVZa++F7SEYXMdDd4rrDUF7p9gr989 g==; X-IronPort-AV: E=McAfee;i="6600,9927,10831"; a="409356435" X-IronPort-AV: E=Sophos;i="6.02,139,1688454000"; d="scan'208";a="409356435" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Sep 2023 08:05:57 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10831"; a="858836453" X-IronPort-AV: E=Sophos;i="6.02,139,1688454000"; d="scan'208";a="858836453" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga002.fm.intel.com with ESMTP; 12 Sep 2023 08:05:55 -0700 Received: by black.fi.intel.com (Postfix, from userid 1003) id 787C8BC0; Tue, 12 Sep 2023 18:05:54 +0300 (EEST) From: Andy Shevchenko To: Andy Shevchenko , linux-kernel@vger.kernel.org Cc: Luis Chamberlain Subject: [PATCH v1 3/6] params: Do not go over the limit when getting the string length Date: Tue, 12 Sep 2023 18:05:48 +0300 Message-Id: <20230912150551.401537-3-andriy.shevchenko@linux.intel.com> X-Mailer: git-send-email 2.40.0.1.gaa8946217a0b In-Reply-To: <20230912150551.401537-1-andriy.shevchenko@linux.intel.com> References: <20230912150551.401537-1-andriy.shevchenko@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We can use strnlen() even on early stages and it prevents from going over the string boundaries in case it's already too long. Signed-off-by: Andy Shevchenko --- kernel/params.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/kernel/params.c b/kernel/params.c index fb594132ffc7..930a5dc2f004 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -259,7 +259,10 @@ EXPORT_SYMBOL_GPL(param_set_uint_minmax); int param_set_charp(const char *val, const struct kernel_param *kp) { - if (strlen(val) > 1024) { + size_t len, maxlen = 1024; + + len = strnlen(val, maxlen + 1); + if (len == maxlen + 1) { pr_err("%s: string parameter too long\n", kp->name); return -ENOSPC; } @@ -269,7 +272,7 @@ int param_set_charp(const char *val, const struct kernel_param *kp) /* This is a hack. We can't kmalloc in early boot, and we * don't need to; this mangled commandline is preserved. */ if (slab_is_available()) { - *(char **)kp->arg = kmalloc_parameter(strlen(val)+1); + *(char **)kp->arg = kmalloc_parameter(len + 1); if (!*(char **)kp->arg) return -ENOMEM; strcpy(*(char **)kp->arg, val); @@ -507,7 +510,7 @@ int param_set_copystring(const char *val, const struct kernel_param *kp) { const struct kparam_string *kps = kp->str; - if (strlen(val)+1 > kps->maxlen) { + if (strnlen(val, kps->maxlen) == kps->maxlen) { pr_err("%s: string doesn't fit in %u chars.\n", kp->name, kps->maxlen-1); return -ENOSPC; -- 2.40.0.1.gaa8946217a0b