Syzbot reported a WARNING in ntfs_extend_initialized_size. The data type of in->i_valid and to is u64 in ntfs_file_mmap(). If their values are greater than LLONG_MAX, overflow will occur because the data types of the parameters valid and new_valid corresponding to the function ntfs_extend_initialized_size() are loff_t. Before calling ntfs_extend_initialized_size() in the ntfs_file_mmap(), the "ni->i_valid < to" has been determined, so the same WARN_ON determination is not required in ntfs_extend_initialized_size(). Just execute the ntfs_extend_initialized_size() in ntfs_extend() to make a WARN_ON check. Reported-and-tested-by: syzbot+e37dd1dfc814b10caa55@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://syzkaller.appspot.com/bug?extid=e37dd1dfc814b10caa55 Signed-off-by: Edward Adam Davis <eadavis@xxxxxx> --- fs/ntfs3/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ntfs3/file.c b/fs/ntfs3/file.c index 6202895a4542..c42454a62314 100644 --- a/fs/ntfs3/file.c +++ b/fs/ntfs3/file.c @@ -178,7 +178,6 @@ static int ntfs_extend_initialized_size(struct file *file, } WARN_ON(is_compressed(ni)); - WARN_ON(valid >= new_valid); for (;;) { u32 zerofrom, len; @@ -400,6 +399,7 @@ static int ntfs_extend(struct inode *inode, loff_t pos, size_t count, } if (extend_init && !is_compressed(ni)) { + WARN_ON(ni->valid >= pos); err = ntfs_extend_initialized_size(file, ni, ni->i_valid, pos); if (err) goto out; -- 2.43.0
