From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: mx.groups.io; dkim=missing; spf=fail (domain: intel.com, ip: , mailfrom: zhichao.gao@intel.com) Received: from mga05.intel.com (mga05.intel.com []) by groups.io with SMTP; Mon, 15 Jul 2019 00:31:00 -0700 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Jul 2019 00:31:00 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,493,1557212400"; d="scan'208";a="187064421" Received: from fieedk001.ccr.corp.intel.com ([10.239.33.119]) by fmsmga001.fm.intel.com with ESMTP; 15 Jul 2019 00:30:59 -0700 From: "Gao, Zhichao" To: devel@edk2.groups.io Cc: Jaben Carsey , Ray Ni , Andrew Fish Subject: [PATCH] ShellPkg/Type.c: Add value check before (LoopVar - 1) Date: Mon, 15 Jul 2019 15:30:05 +0800 Message-Id: <20190715073007.25732-2-zhichao.gao@intel.com> X-Mailer: git-send-email 2.21.0.windows.1 In-Reply-To: <20190715073007.25732-1-zhichao.gao@intel.com> References: <20190715073007.25732-1-zhichao.gao@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1964 If the file begin with single line Feed ('\n'), then "AsciiChar == '\n' && ((CHAR8*)Buffer)[LoopVar-1] != '\r'" would cause a underflow. Add this condition "(AsciiChar == '\n' && LoopVar == 0)" before it to make sure (LoopVar - 1) would never encounter a underflow. Cc: Jaben Carsey Cc: Ray Ni Cc: Andrew Fish Signed-off-by: Zhichao Gao --- ShellPkg/Library/UefiShellLevel3CommandsLib/Type.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/ShellPkg/Library/UefiShellLevel3CommandsLib/Type.c b/ShellPkg/Library/UefiShellLevel3CommandsLib/Type.c index 4efc0a8e24..c1f670c713 100644 --- a/ShellPkg/Library/UefiShellLevel3CommandsLib/Type.c +++ b/ShellPkg/Library/UefiShellLevel3CommandsLib/Type.c @@ -78,12 +78,13 @@ TypeFileByHandle ( // Allow Line Feed (LF) (0xA) & Carriage Return (CR) (0xD) // characters to be displayed as is. // - if (AsciiChar == '\n' && ((CHAR8*)Buffer)[LoopVar-1] != '\r') { + if ((AsciiChar == '\n' && LoopVar == 0) || + (AsciiChar == '\n' && ((CHAR8*)Buffer)[LoopVar-1] != '\r')) { // - // In case Line Feed (0xA) is encountered & Carriage Return (0xD) - // was not the previous character, print CR and LF. This is because - // Shell 2.0 requires carriage return with line feed for displaying - // each new line from left. + // In case file begin with single line Feed or Line Feed (0xA) is + // encountered & Carriage Return (0xD) was not previous character, + // print CR and LF. This is because Shell 2.0 requires carriage + // return Swith line feed for displaying each new line from left. // ShellPrintEx (-1, -1, L"\r\n"); continue; -- 2.21.0.windows.1