[lxc-devel] [PATCH] fortify: check the value returned from write(2)

[Dwight Engen]

Also check that we wrote the amount we expected to. The write on the pty
is blocking but we could still get a short write on EINTR, so we should
SYSERROR it.

Signed-off-by: Dwight Engen <dwight.engen at oracle.com>
---
 src/lxc/lxc_console.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/lxc/lxc_console.c b/src/lxc/lxc_console.c
index 3dd2155..643c442 100644
--- a/src/lxc/lxc_console.c
+++ b/src/lxc/lxc_console.c
@@ -165,14 +165,18 @@ static int master_handler(int fd, void *data,
struct lxc_epoll_descr *descr) {
 	char buf[1024];
 	int *peer = (int *)data;
-	int r;
+	int r,w;
 
 	r = read(fd, buf, sizeof(buf));
 	if (r < 0) {
 		SYSERROR("failed to read");
 		return 1;
 	}
-	r = write(*peer, buf, r);
+	w = write(*peer, buf, r);
+	if (w < 0 || w != r) {
+		SYSERROR("failed to write");
+		return 1;
+	}
 
 	return 0;
 }
-- 
1.7.12.3