[PATCH AUTOSEL 4.19 639/671] f2fs: fix potential overflow

Sasha Levin
2020-01-16T17:16:17Z

From: Chao Yu <yuchao0@huawei.com>

[ Upstream commit 1f0d5c911b64165c9754139a26c8c2fad352c132 ]

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: Sasha Levin <sashal@kernel.org>
---
fs/f2fs/data.c | 2 +-
fs/f2fs/file.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index a7436ad19458..c81a1f3f0a10 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1857,7 +1857,7 @@ static int __write_data_page(struct page *page, bool *submitted,
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;
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 5eef2a8b29ab..59b5c0b032bb 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1101,7 +1101,7 @@ static int __clone_blkaddrs(struct inode *src_inode, struct inode *dst_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));
--
2.20.1