From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Rue , Mike Kravetz , Anders Roxell , Michal Hocko , Yisheng Xie , "Kirill A . Shutemov" , Nic Losby , Andrew Morton , Linus Torvalds Subject: [PATCH 4.14 48/49] hugetlbfs: fix bug in pgoff overflow checking Date: Tue, 17 Apr 2018 17:59:27 +0200 Message-Id: <20180417155717.326675545@linuxfoundation.org> In-Reply-To: <20180417155715.032245882@linuxfoundation.org> References: <20180417155715.032245882@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mike Kravetz commit 5df63c2a149ae65a9ec239e7c2af44efa6f79beb upstream. This is a fix for a regression in 32 bit kernels caused by an invalid check for pgoff overflow in hugetlbfs mmap setup. The check incorrectly specified that the size of a loff_t was the same as the size of a long. The regression prevents mapping hugetlbfs files at offsets greater than 4GB on 32 bit kernels. On 32 bit kernels conversion from a page based unsigned long can not overflow a loff_t byte offset. Therefore, skip this check if sizeof(unsigned long) != sizeof(loff_t). Link: http://lkml.kernel.org/r/20180330145402.5053-1-mike.kravetz@oracle.com Fixes: 63489f8e8211 ("hugetlbfs: check for pgoff value overflow") Reported-by: Dan Rue Signed-off-by: Mike Kravetz Tested-by: Anders Roxell Cc: Michal Hocko Cc: Yisheng Xie Cc: "Kirill A . Shutemov" Cc: Nic Losby Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/hugetlbfs/inode.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -148,10 +148,14 @@ static int hugetlbfs_file_mmap(struct fi /* * page based offset in vm_pgoff could be sufficiently large to - * overflow a (l)off_t when converted to byte offset. + * overflow a loff_t when converted to byte offset. This can + * only happen on architectures where sizeof(loff_t) == + * sizeof(unsigned long). So, only check in those instances. */ - if (vma->vm_pgoff & PGOFF_LOFFT_MAX) - return -EINVAL; + if (sizeof(unsigned long) == sizeof(loff_t)) { + if (vma->vm_pgoff & PGOFF_LOFFT_MAX) + return -EINVAL; + } /* must be huge page aligned */ if (vma->vm_pgoff & (~huge_page_mask(h) >> PAGE_SHIFT))