Check the return error of set[e][ug]id. While this can never fail in the

current version of FreeBSD, this isn't guarenteed by the API.
Custom security modules, or future implementations of the setuid and
setgid may fail.

Submitted by:	Erik Cederstrand
Approved by:	cperciva
MFC after:	3 days

1 files changed, 4 insertions, 1 deletions

diff --git a/libexec/tftpd/tftpd.c b/libexec/tftpd/tftpd.c
index 7363abf3c0e95..a0010b3c50322 100644
--- a/libexec/tftpd/tftpd.c
+++ b/libexec/tftpd/tftpd.c
@@ -371,7 +371,10 @@ main(int argc, char *argv[])
 		}
 		chdir("/");
 		setgroups(1, &nobody->pw_gid);
-		setuid(nobody->pw_uid);
+		if (setuid(nobody->pw_uid) != 0) {
+			tftp_log(LOG_ERR, "setuid failed");
+			exit(1);
+		}
 	}
 
 	len = sizeof(me_sock);