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| author | Mike Kravetz <mike.kravetz@oracle.com> | 2018-04-05 16:18:21 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-05 21:36:21 -0700 |
| commit | 5df63c2a149ae65a9ec239e7c2af44efa6f79beb (patch) | |
| tree | 5d2d3541de5ae08a28a208c069669f75cf160b07 | |
| parent | 7bbaf27d9c83037b6e60a818e57bdbedf6bc15be (diff) | |
| download | linux-5df63c2a149ae65a9ec239e7c2af44efa6f79beb.tar.bz2 | |
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>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/hugetlbfs/inode.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index b9a254dcc0e7..d508c7844681 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -138,10 +138,14 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) /* * 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)) |