[PATCH 5.4 176/203] f2fs: fix potential overflow

Greg Kroah-Hartman
2020-01-16T23:26:36Z

From: Chao Yu <yuchao0@huawei.com>

commit 1f0d5c911b64165c9754139a26c8c2fad352c132 upstream.

We expect 64-bit calculation result from below statement, however
in 32-bit machine, looped left shift operation on pgoff_t type
variable may cause overflow issue, fix it by forcing type cast.

page->index << PAGE_SHIFT;

Fixes: 26de9b117130 ("f2fs: avoid unnecessary updating inode during fsync")
Fixes: 0a2aa8fbb969 ("f2fs: refactor __exchange_data_block for speed up")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/f2fs/data.c | 2 +-
fs/f2fs/file.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2098,7 +2098,7 @@ static int __write_data_page(struct page
loff_t i_size = i_size_read(inode);
const pgoff_t end_index = ((unsigned long long) i_size)
>> PAGE_SHIFT;
- loff_t psize = (page->index + 1) << PAGE_SHIFT;
+ loff_t psize = (loff_t)(page->index + 1) << PAGE_SHIFT;
unsigned offset = 0;
bool need_balance_fs = false;
int err = 0;
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1139,7 +1139,7 @@ static int __clone_blkaddrs(struct inode
}
dn.ofs_in_node++;
i++;
- new_size = (dst + i) << PAGE_SHIFT;
+ new_size = (loff_t)(dst + i) << PAGE_SHIFT;
if (dst_inode->i_size < new_size)
f2fs_i_size_write(dst_inode, new_size);
} while (--ilen && (do_replace[i] || blkaddr[i] == NULL_ADDR));