luojiajun report a problem[1] two years ago which seems still exists in mainline. vfs_fallocate can avoid 'offset + len' trigger overflow, but 'offset + len + hpage_size - 1' may overflow too and will lead to a wrong 'end'. luojiajun give a solution which can fix the wrong 'end' but leave the overflow still happened. Fix it with DIV_ROUND_UP_ULL. [1] https://patchwork.kernel.org/project/linux-mm/patch/1554775226-67213-1-git-send-email-luojiajun3@xxxxxxxxxx/ Signed-off-by: yangerkun <yangerkun@xxxxxxxxxx> --- fs/hugetlbfs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 49d2e686be74..92ac056e8011 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -651,7 +651,7 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset, * as well as being converted to page offsets. */ start = offset >> hpage_shift; - end = (offset + len + hpage_size - 1) >> hpage_shift; + end = DIV_ROUND_UP_ULL(offset + len, hpage_size); inode_lock(inode); -- 2.31.1
