Commit d80caeb9 authored Mar 21, 2017 by Alexander Potapenko Committed by Greg Kroah-Hartman Mar 30, 2017

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



[ Upstream commit d515684d78148884d5fc425ba904c50f03844020 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent c87ef873

net/ipv6/udp.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1037,6 +1037,7 @@ 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) {
		@@ -1156,7 +1157,6 @@ int udpv6_sendmsg(struct sock sk, struct msghdr msg, size_t len)
		fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;

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

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