path: root/fs/hugetlbfs
diff options
authorMike Kravetz <mike.kravetz@oracle.com>2018-04-05 16:18:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-05 21:36:21 -0700
commit5df63c2a149ae65a9ec239e7c2af44efa6f79beb (patch)
tree5d2d3541de5ae08a28a208c069669f75cf160b07 /fs/hugetlbfs
parent7bbaf27d9c83037b6e60a818e57bdbedf6bc15be (diff)
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>
Diffstat (limited to 'fs/hugetlbfs')
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))

Privacy Policy