[PATCH 1/5] torture/ioctl: fix check_[zero/pattern]() for len=0

[David Disseldorp]

Subtraction currently triggers an underflow.

Signed-off-by: David Disseldorp <ddiss at samba.org>
---
 source4/torture/smb2/ioctl.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/source4/torture/smb2/ioctl.c b/source4/torture/smb2/ioctl.c
index 344ff0e..208a63f 100644
--- a/source4/torture/smb2/ioctl.c
+++ b/source4/torture/smb2/ioctl.c
@@ -164,6 +164,10 @@ static bool check_pattern(struct torture_context *torture,
 	struct smb2_read r;
 	NTSTATUS status;
 
+	if (len == 0) {
+		return true;
+	}
+
 	ZERO_STRUCT(r);
 	r.in.file.handle = h;
 	r.in.length      = len;
@@ -194,6 +198,10 @@ static bool check_zero(struct torture_context *torture,
 	struct smb2_read r;
 	NTSTATUS status;
 
+	if (len == 0) {
+		return true;
+	}
+
 	ZERO_STRUCT(r);
 	r.in.file.handle = h;
 	r.in.length      = len;
-- 
2.1.4