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| author | Chao Yu <chao2.yu@samsung.com> | 2015-09-11 14:43:52 +0800 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2015-10-09 16:20:50 -0700 |
| commit | 9edcdabf36422d15d01db73b0fa5487e418beff6 (patch) | |
| tree | 0a0cf8522db1e617ef6cf9379ae9b5fd89e8a3bd /fs/f2fs/data.c | |
| parent | 100136acfb4023ab7dc899192e95aca9aedfe98a (diff) | |
| download | lwn-9edcdabf36422d15d01db73b0fa5487e418beff6.tar.gz lwn-9edcdabf36422d15d01db73b0fa5487e418beff6.zip | |
f2fs: fix overflow of size calculation
We have potential overflow issue when calculating size of object, when
we left shift index with PAGE_CACHE_SHIFT bits, if type of index has only
32-bits space in 32-bit architecture, left shifting will incur overflow,
i.e:
pgoff_t index = 0xFFFFFFFF;
loff_t size = index << PAGE_CACHE_SHIFT;
size: 0xFFFFF000
So we should cast index with 64-bits type to avoid this issue.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs/data.c')
| -rw-r--r-- | fs/f2fs/data.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index a82abe921b89..681373e1da92 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -447,9 +447,9 @@ repeat: lock_page(page); } got_it: - if (new_i_size && - i_size_read(inode) < ((index + 1) << PAGE_CACHE_SHIFT)) { - i_size_write(inode, ((index + 1) << PAGE_CACHE_SHIFT)); + if (new_i_size && i_size_read(inode) < + ((loff_t)(index + 1) << PAGE_CACHE_SHIFT)) { + i_size_write(inode, ((loff_t)(index + 1) << PAGE_CACHE_SHIFT)); /* Only the directory inode sets new_i_size */ set_inode_flag(F2FS_I(inode), FI_UPDATE_DIR); } @@ -489,8 +489,9 @@ alloc: /* update i_size */ fofs = start_bidx_of_node(ofs_of_node(dn->node_page), fi) + dn->ofs_in_node; - if (i_size_read(dn->inode) < ((fofs + 1) << PAGE_CACHE_SHIFT)) - i_size_write(dn->inode, ((fofs + 1) << PAGE_CACHE_SHIFT)); + if (i_size_read(dn->inode) < ((loff_t)(fofs + 1) << PAGE_CACHE_SHIFT)) + i_size_write(dn->inode, + ((loff_t)(fofs + 1) << PAGE_CACHE_SHIFT)); /* direct IO doesn't use extent cache to maximize the performance */ f2fs_drop_largest_extent(dn->inode, fofs); |