lib: Fix `terminal monitor` uninited memory usage on freebsd

When `terminal monitor` is issued I am seeing this for valgrind on freebsd:

2022/03/24 18:07:45 ZEBRA: [RHJDG-5FNSK][EC 100663304] can't open configuration file [/usr/local/etc/frr/zebra.conf]
==52993== Syscall param sendmsg(sendmsg.msg_control) points to uninitialised byte(s)
==52993==    at 0x4CE268A: _sendmsg (in /lib/libc.so.7)
==52993==    by 0x4B96245: ??? (in /lib/libthr.so.3)
==52993==    by 0x4CDF329: sendmsg (in /lib/libc.so.7)
==52993==    by 0x49A9994: vtysh_do_pass_fd (vty.c:2041)
==52993==    by 0x49A9994: vtysh_flush (vty.c:2070)
==52993==    by 0x499F4CE: thread_call (thread.c:2002)
==52993==    by 0x495D317: frr_run (libfrr.c:1196)
==52993==    by 0x2B4068: main (main.c:471)
==52993==  Address 0x7fc000864 is on thread 1's stack
==52993==  in frame #3, created by vtysh_flush (vty.c:2065)

Fix by initializing the memory to `0`

Signed-off-by: Donald Sharp <sharpd@nvidia.com>

diff --git a/lib/vty.c b/lib/vty.c
index 78ef9894de89c7314484b093d5689ce69bebc411..619d51e1ce7dcb8fcc1ccbdd220fa404b04876fc 100644 (file)
--- a/lib/vty.c
+++ b/lib/vty.c
@@ -2033,6 +2033,7 @@ static int vtysh_do_pass_fd(struct vty *vty)
        struct cmsghdr *cmh = CMSG_FIRSTHDR(&mh);
        ssize_t ret;
 
+       memset(&u.buf, 0, sizeof(u.buf));
        cmh->cmsg_level = SOL_SOCKET;
        cmh->cmsg_type = SCM_RIGHTS;
        cmh->cmsg_len = CMSG_LEN(sizeof(int));