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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The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
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@xxxxxxxxxx
Fixes: 63489f8e8211 ("hugetlbfs: check for pgoff value overflow")
Reported-by: Dan Rue <dan.rue@xxxxxxxxxx>
Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Yisheng Xie <xieyisheng1@xxxxxxxxxx>
Cc: "Kirill A . Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Nic Losby <blurbdust@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxx 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
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