From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753465AbaBEReh (ORCPT ); Wed, 5 Feb 2014 12:34:37 -0500 Received: from mx1.redhat.com ([209.132.183.28]:9892 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753018AbaBERef (ORCPT ); Wed, 5 Feb 2014 12:34:35 -0500 From: Denys Vlasenko To: linux-kernel@vger.kernel.org Cc: Denys Vlasenko , Al Viro , Oleg Nesterov , Jan Kratochvil , Amerigo Wang , "Jonathan M. Foote" , Roland McGrath , Pedro Alves , Fengguang Wu , Stephen Rothwell Subject: [PATCH] fs: fix d_path() with zero-length input buffer Date: Wed, 5 Feb 2014 18:34:07 +0100 Message-Id: <1391621647-7905-1-git-send-email-dvlasenk@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In prepend_name(), *buflen < dlen + 1 comparison is buggy because dlen has unsigned data type, and we can reach this location with *buflen == -1. The fix casts dlen to int. Bug reports: https://bugzilla.redhat.com/show_bug.cgi?id=1050964 https://bugzilla.redhat.com/show_bug.cgi?id=1060384 Signed-off-by: Denys Vlasenko Cc: Al Viro Cc: Oleg Nesterov Cc: Jan Kratochvil Cc: Amerigo Wang Cc: "Jonathan M. Foote" Cc: Roland McGrath Cc: Pedro Alves Cc: Fengguang Wu Cc: Stephen Rothwell --- fs/dcache.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/dcache.c b/fs/dcache.c index 265e0ce..40ded0c 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2833,7 +2833,7 @@ static int prepend_name(char **buffer, int *buflen, struct qstr *name) u32 dlen = ACCESS_ONCE(name->len); char *p; - if (*buflen < dlen + 1) + if (*buflen < (int)dlen + 1) return -ENAMETOOLONG; *buflen -= dlen + 1; p = *buffer -= dlen + 1; -- 1.8.1.4