Merge branch 'ipv6-fix-EFAULT-on-sendto-with-icmpv6-and-hdrincl'

Olivier Matz says:

====================
ipv6: fix EFAULT on sendto with icmpv6 and hdrincl

The following code returns EFAULT (Bad address):

  s = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
  setsockopt(s, SOL_IPV6, IPV6_HDRINCL, 1);
  sendto(ipv6_icmp6_packet, addr);   /* returns -1, errno = EFAULT */

The problem is fixed in the second patch. The first one aligns the
code to ipv4, to avoid a race condition in the second patch.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2019-06-06 10:29:21 -07:00
commit 8d037f92de

View File

@ -783,6 +783,7 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
struct flowi6 fl6;
struct ipcm6_cookie ipc6;
int addr_len = msg->msg_namelen;
int hdrincl;
u16 proto;
int err;
@ -796,6 +797,13 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
if (msg->msg_flags & MSG_OOB)
return -EOPNOTSUPP;
/* hdrincl should be READ_ONCE(inet->hdrincl)
* but READ_ONCE() doesn't work with bit fields.
* Doing this indirectly yields the same result.
*/
hdrincl = inet->hdrincl;
hdrincl = READ_ONCE(hdrincl);
/*
* Get and verify the address.
*/
@ -887,11 +895,14 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
opt = ipv6_fixup_options(&opt_space, opt);
fl6.flowi6_proto = proto;
rfv.msg = msg;
rfv.hlen = 0;
err = rawv6_probe_proto_opt(&rfv, &fl6);
if (err)
goto out;
if (!hdrincl) {
rfv.msg = msg;
rfv.hlen = 0;
err = rawv6_probe_proto_opt(&rfv, &fl6);
if (err)
goto out;
}
if (!ipv6_addr_any(daddr))
fl6.daddr = *daddr;
@ -908,7 +919,7 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
fl6.flowi6_oif = np->ucast_oif;
security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
if (inet->hdrincl)
if (hdrincl)
fl6.flowi6_flags |= FLOWI_FLAG_KNOWN_NH;
if (ipc6.tclass < 0)
@ -931,7 +942,7 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
goto do_confirm;
back_from_confirm:
if (inet->hdrincl)
if (hdrincl)
err = rawv6_send_hdrinc(sk, msg, len, &fl6, &dst,
msg->msg_flags, &ipc6.sockc);
else {