From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932874AbaLBEEZ (ORCPT ); Mon, 1 Dec 2014 23:04:25 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:34530 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932655AbaLBEEY (ORCPT ); Mon, 1 Dec 2014 23:04:24 -0500 From: Sasha Levin To: linux-kernel@vger.kernel.org Cc: Sasha Levin , Alexander Viro , linux-fsdevel@vger.kernel.org Subject: [PATCH] vfs: calculate seek offsets using unsigned variables Date: Mon, 1 Dec 2014 23:04:07 -0500 Message-Id: <1417493050-13594-3-git-send-email-sasha.levin@oracle.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1417493050-13594-1-git-send-email-sasha.levin@oracle.com> References: <1417493050-13594-1-git-send-email-sasha.levin@oracle.com> X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Adding two loff_ts means adding two signed integers. Adding two such integers when they are unchecked might cause an overflow which is undefined for signed integers. Avoid it by doing the math using unsigned cast and casting it back implicitly into loff_t. Signed-off-by: Sasha Levin --- fs/read_write.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/read_write.c b/fs/read_write.c index c0805c9..54311f4 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -91,7 +91,7 @@ generic_file_llseek_size(struct file *file, loff_t offset, int whence, { switch (whence) { case SEEK_END: - offset += eof; + offset += (u64)eof; break; case SEEK_CUR: /* @@ -108,7 +108,7 @@ generic_file_llseek_size(struct file *file, loff_t offset, int whence, * like SEEK_SET. */ spin_lock(&file->f_lock); - offset = vfs_setpos(file, file->f_pos + offset, maxsize); + offset = vfs_setpos(file, (u64)file->f_pos + offset, maxsize); spin_unlock(&file->f_lock); return offset; case SEEK_DATA: -- 1.7.10.4