From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966604AbcKOJTK (ORCPT ); Tue, 15 Nov 2016 04:19:10 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58072 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966532AbcKOJTH (ORCPT ); Tue, 15 Nov 2016 04:19:07 -0500 From: Li Wang To: adilger@dilger.ca, viro@zeniv.linux.org.uk Cc: liwang@redhat.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] vfs: fix put_compat_statfs64() does not handle errors Date: Tue, 15 Nov 2016 17:19:01 +0800 Message-Id: <1479201541-9145-1-git-send-email-liwang@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Tue, 15 Nov 2016 09:19:06 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org put_compat_statfs64() does NOT return -1 and setting errno to EOVERFLOW when some variables(like: f_bsize) overflowed in the returned struct. The reason is that the ubuf->f_blocks is __u64 type, it couldn't be 4bits as the judgement in put_comat_statfs64(). Here correct the __u32 variables(in struct compat_statfs64) for comparison. reproducer: step1. mount hugetlbfs with two different pagesize on ppc64 arch. $ hugeadm --pool-pages-max 16M:0 $ hugeadm --create-mount $ mount | grep -i hugetlbfs none on /var/lib/hugetlbfs/pagesize-16MB type hugetlbfs (rw,relatime,seclabel,pagesize=16777216) none on /var/lib/hugetlbfs/pagesize-16GB type hugetlbfs (rw,relatime,seclabel,pagesize=17179869184) step2. compile & run this C program. $ cat statfs64_test.c #define _LARGEFILE64_SOURCE #include #include #include int main() { struct statfs64 sb; int err; err = syscall(SYS_statfs64, "/var/lib/hugetlbfs/pagesize-16GB", sizeof(sb), &sb); if (err) return -1; printf("sizeof f_bsize = %d, f_bsize=%ld\n", sizeof(sb.f_bsize), sb.f_bsize); return 0; } $ gcc -m32 statfs64_test.c $ ./a.out sizeof f_bsize = 4, f_bsize=0 Signed-off-by: Li Wang --- fs/compat.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/compat.c b/fs/compat.c index bd064a2..543b48c 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -253,9 +253,9 @@ static int put_compat_statfs(struct compat_statfs __user *ubuf, struct kstatfs * static int put_compat_statfs64(struct compat_statfs64 __user *ubuf, struct kstatfs *kbuf) { - if (sizeof ubuf->f_blocks == 4) { - if ((kbuf->f_blocks | kbuf->f_bfree | kbuf->f_bavail | - kbuf->f_bsize | kbuf->f_frsize) & 0xffffffff00000000ULL) + if (sizeof(ubuf->f_bsize) == 4) { + if ((kbuf->f_type | kbuf->f_bsize | kbuf->f_namelen | + kbuf->f_frsize | kbuf->f_flags) & 0xffffffff00000000ULL) return -EOVERFLOW; /* f_files and f_ffree may be -1; it's okay * to stuff that into 32 bits */ -- 1.8.3.1