diff options
| author | Wei Fang <fangwei1@huawei.com> | 2017-01-22 12:21:02 +0800 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-04-13 12:34:47 +0200 |
| commit | 07e64b221d945ebea2052835cea6afbffa1af5b2 (patch) | |
| tree | b41e569e816394ed1752f4f765e4a8b068ed2c97 | |
| parent | 3d9cd41d23b3424c4359b6187bac5689e8075b80 (diff) | |
f2fs: fix a dead loop in f2fs_fiemap()
A dead loop can be triggered in f2fs_fiemap() using the test case
as below:
...
fd = open();
fallocate(fd, 0, 0, 4294967296);
ioctl(fd, FS_IOC_FIEMAP, fiemap_buf);
...
It's caused by an overflow in __get_data_block():
...
bh->b_size = map.m_len << inode->i_blkbits;
...
map.m_len is an unsigned int, and bh->b_size is a size_t which is 64 bits
on 64 bits archtecture, type conversion from an unsigned int to a size_t
will result in an overflow.
In the above-mentioned case, bh->b_size will be zero, and f2fs_fiemap()
will call get_data_block() at block 0 again an again.
Fix this by adding a force conversion before left shift.
Signed-off-by: Wei Fang <fangwei1@huawei.com>
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
| -rw-r--r-- | fs/f2fs/data.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index eeeb0be68..4c6a1472c 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -962,7 +962,7 @@ static int __get_data_block(struct inode *inode, sector_t iblock, if (!err) { map_bh(bh, inode->i_sb, map.m_pblk); bh->b_state = (bh->b_state & ~F2FS_MAP_FLAGS) | map.m_flags; - bh->b_size = map.m_len << inode->i_blkbits; + bh->b_size = (u64)map.m_len << inode->i_blkbits; } return err; } |