[PATCH v2] xfs_io: actually check copy file range helper return values

["Darrick J. Wong" <darrick.wong@oracle.com>]

From: Darrick J. Wong <darrick.wong@oracle.com>

We need to check the return value of copy_src_filesize and
copy_dst_truncate because either could return -1 due to fstat/ftruncate
failure.

Fixes: 628e112afdd98c5 ("xfs_io: implement 'copy_range' command")
Cc: schumaker.anna@gmail.com
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
v2: fix return values and overflow problems
---
 io/copy_file_range.c |   17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/io/copy_file_range.c b/io/copy_file_range.c
index 4e2969c9..d069e5bb 100644
--- a/io/copy_file_range.c
+++ b/io/copy_file_range.c
@@ -120,11 +120,24 @@ copy_range_f(int argc, char **argv)
 		return 0;
 
 	if (src == 0 && dst == 0 && len == 0) {
-		len = copy_src_filesize(fd);
-		copy_dst_truncate();
+		off64_t	sz;
+
+		sz = copy_src_filesize(fd);
+		if (sz < 0 || (unsigned long long)sz > SIZE_MAX) {
+			ret = 1;
+			goto out;
+		}
+		len = sz;
+
+		ret = copy_dst_truncate();
+		if (ret < 0) {
+			ret = 1;
+			goto out;
+		}
 	}
 
 	ret = copy_file_range_cmd(fd, &src, &dst, len);
+out:
 	close(fd);
 	return ret;
 }