Commit d515684d authored Mar 21, 2017 by Alexander Potapenko Committed by David S. Miller Mar 22, 2017

ipv6: make sure to initialize sockc.tsflags before first use



In the case udp_sk(sk)->pending is AF_INET6, udpv6_sendmsg() would
jump to do_append_data, skipping the initialization of sockc.tsflags.
Fix the problem by moving sockc.tsflags initialization earlier.

The bug was detected with KMSAN.

Fixes: c14ac945 ("sock: enable timestamping using control messages")
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 1b33c0d2

net/ipv6/udp.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1035,6 +1035,7 @@ int udpv6_sendmsg(struct sock sk, struct msghdr msg, size_t len)
		ipc6.hlimit = -1;
		ipc6.tclass = -1;
		ipc6.dontfrag = -1;
		sockc.tsflags = sk->sk_tsflags;

		/* destination address check */
		if (sin6) {
		@@ -1159,7 +1160,6 @@ int udpv6_sendmsg(struct sock sk, struct msghdr msg, size_t len)

		fl6.flowi6_mark = sk->sk_mark;
		fl6.flowi6_uid = sk->sk_uid;
		sockc.tsflags = sk->sk_tsflags;

		if (msg->msg_controllen) {
		opt = &opt_space;