+ hugetlbfs-fix-bug-in-pgoff-overflow-checking.patch added to -mm tree

+ hugetlbfs-fix-bug-in-pgoff-overflow-checking.patch added to -mm tree

[akpm]

The patch titled
     Subject: hugetlbfs: fix bug in pgoff overflow checking
has been added to the -mm tree.  Its filename is
     hugetlbfs-fix-bug-in-pgoff-overflow-checking.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/hugetlbfs-fix-bug-in-pgoff-overflow-checking.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/hugetlbfs-fix-bug-in-pgoff-overflow-checking.patch

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------------------------------------------------------
From: Mike Kravetz <mike.kravetz@oracle.com>
Subject: hugetlbfs: fix bug in pgoff overflow checking

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 <dan.rue@linaro.org>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Yisheng Xie <xieyisheng1@huawei.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Nic Losby <blurbdust@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/hugetlbfs/inode.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff -puN fs/hugetlbfs/inode.c~hugetlbfs-fix-bug-in-pgoff-overflow-checking fs/hugetlbfs/inode.c
--- a/fs/hugetlbfs/inode.c~hugetlbfs-fix-bug-in-pgoff-overflow-checking
+++ a/fs/hugetlbfs/inode.c
@@ -138,10 +138,14 @@ 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))
_

Patches currently in -mm which might be from mike.kravetz@oracle.com are

hugetlbfs-fix-bug-in-pgoff-overflow-checking.patch
mm-hugetlbfs-move-hugetlbfs_i-outside-ifdef-config_hugetlbfs.patch
mm-memfd-split-out-memfd-for-use-by-multiple-filesystems.patch
mm-memfd-remove-memfd-code-from-shmem-files-and-use-new-memfd-files.patch
mm-make-start_isolate_page_range-fail-if-already-isolated.patch