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| author |   Andreas Gruenbacher <agruenba@redhat.com> | 2019-11-07 07:28:18 -0800 |
|---|---|---|
| committer |   Darrick J. Wong <darrick.wong@oracle.com> | 2019-11-07 07:28:18 -0800 |
| commit | add66fcbd3fbe5aa0dd4dddfa23e119c12989a27 (patch) | |
| tree | d9d71271fe45b9a3ba59c9c17bc5534efb149f67 /fs/iomap | |
| parent | fs/iomap: remove redundant check in iomap_dio_rw() (diff) | |
| download | wireguard-linux-add66fcbd3fbe5aa0dd4dddfa23e119c12989a27.tar.xz wireguard-linux-add66fcbd3fbe5aa0dd4dddfa23e119c12989a27.zip | |
iomap: Fix overflow in iomap_page_mkwrite
On architectures where loff_t is wider than pgoff_t, the expression
((page->index + 1) << PAGE_SHIFT) can overflow. Rewrite to use the page
offset, which we already compute here anyway.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs/iomap')
| -rw-r--r-- | fs/iomap/buffered-io.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index c62e807956b6..d33c7bc5ee92 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -1067,20 +1067,19 @@ vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops) lock_page(page); size = i_size_read(inode); - if ((page->mapping != inode->i_mapping) || - (page_offset(page) > size)) { + offset = page_offset(page); + if (page->mapping != inode->i_mapping || offset > size) { /* We overload EFAULT to mean page got truncated */ ret = -EFAULT; goto out_unlock; } /* page is wholly or partially inside EOF */ - if (((page->index + 1) << PAGE_SHIFT) > size) + if (offset > size - PAGE_SIZE) length = offset_in_page(size); else length = PAGE_SIZE; - offset = page_offset(page); while (length > 0) { ret = iomap_apply(inode, offset, length, IOMAP_WRITE | IOMAP_FAULT, ops, page, |