tools: kwboot: Fix restoring terminal

Call tcsetattr() only if the file descriptor is valid. It may be
invalidated by previous lines (if it is not a tty descriptor).

Signed-off-by: Pali Rohár <[email protected]>
Reviewed-by: Marek Behún <[email protected]>
Reviewed-by: Stefan Roese <[email protected]>
Reviewed-by: Chris Packham <[email protected]>
Tested-by: Chris Packham <[email protected]>

1 files changed, 2 insertions, 1 deletions

diff --git a/tools/kwboot.c b/tools/kwboot.c
index 1ba5ded5d38..7fa742d84cc 100644
--- a/tools/kwboot.c
+++ b/tools/kwboot.c
@@ -558,7 +558,8 @@ kwboot_terminal(int tty)
 		}
 	} while (quit[s] != 0);
 
-	tcsetattr(in, TCSANOW, &otio);
+	if (in >= 0)
+		tcsetattr(in, TCSANOW, &otio);
 out:
 	return rc;
 }