odhcpd: fix passing possible negative parameter

Prevent passing negative argument to read; detected by Coverity in CID1412381

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/src/odhcpd.c b/src/odhcpd.c
index 0e0002d..7c6c144 100644
--- a/src/odhcpd.c
+++ b/src/odhcpd.c
@@ -128,6 +128,9 @@ int odhcpd_get_interface_config(const char *ifname, const char *what)
 	snprintf(buf, sizeof(buf), sysctl_pattern, ifname, what);
 
 	int fd = open(buf, O_RDONLY);
+	if (fd < 0)
+		return -1;
+
 	ssize_t len = read(fd, buf, sizeof(buf) - 1);
 	close(fd);