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authorPaolo Abeni <pabeni@redhat.com>2021-04-15 16:44:52 -0700
committerDavid S. Miller <davem@davemloft.net>2021-04-16 15:23:09 -0700
commitd9e4c129181004ec94b315b0c9db5eeb09da75e6 (patch)
treec320ac93029103307b2951e0101583ff5c8ba535
parent0abdde82b163600dcafb80da6e155dbf60c331bc (diff)
mptcp: only admit explicitly supported sockopt
Unrolling mcast state at msk dismantel time is bug prone, as syzkaller reported: ====================================================== WARNING: possible circular locking dependency detected 5.11.0-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor905/8822 is trying to acquire lock: ffffffff8d678fe8 (rtnl_mutex){+.+.}-{3:3}, at: ipv6_sock_mc_close+0xd7/0x110 net/ipv6/mcast.c:323 but task is already holding lock: ffff888024390120 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1600 [inline] ffff888024390120 (sk_lock-AF_INET6){+.+.}-{0:0}, at: mptcp6_release+0x57/0x130 net/mptcp/protocol.c:3507 which lock already depends on the new lock. Instead we can simply forbid any mcast-related setsockopt. Let's do the same with all other non supported sockopts. Fixes: 717e79c867ca5 ("mptcp: Add setsockopt()/getsockopt() socket operations") Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/mptcp/sockopt.c216
1 files changed, 216 insertions, 0 deletions
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index 479f75653969..fb98fab252df 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -82,6 +82,219 @@ static int mptcp_setsockopt_v6(struct mptcp_sock *msk, int optname,
return ret;
}
+static bool mptcp_supported_sockopt(int level, int optname)
+{
+ if (level == SOL_SOCKET) {
+ switch (optname) {
+ case SO_DEBUG:
+ case SO_REUSEPORT:
+ case SO_REUSEADDR:
+
+ /* the following ones need a better implementation,
+ * but are quite common we want to preserve them
+ */
+ case SO_BINDTODEVICE:
+ case SO_SNDBUF:
+ case SO_SNDBUFFORCE:
+ case SO_RCVBUF:
+ case SO_RCVBUFFORCE:
+ case SO_KEEPALIVE:
+ case SO_PRIORITY:
+ case SO_LINGER:
+ case SO_TIMESTAMP_OLD:
+ case SO_TIMESTAMP_NEW:
+ case SO_TIMESTAMPNS_OLD:
+ case SO_TIMESTAMPNS_NEW:
+ case SO_TIMESTAMPING_OLD:
+ case SO_TIMESTAMPING_NEW:
+ case SO_RCVLOWAT:
+ case SO_RCVTIMEO_OLD:
+ case SO_RCVTIMEO_NEW:
+ case SO_SNDTIMEO_OLD:
+ case SO_SNDTIMEO_NEW:
+ case SO_MARK:
+ case SO_INCOMING_CPU:
+ case SO_BINDTOIFINDEX:
+ case SO_BUSY_POLL:
+ case SO_PREFER_BUSY_POLL:
+ case SO_BUSY_POLL_BUDGET:
+
+ /* next ones are no-op for plain TCP */
+ case SO_NO_CHECK:
+ case SO_DONTROUTE:
+ case SO_BROADCAST:
+ case SO_BSDCOMPAT:
+ case SO_PASSCRED:
+ case SO_PASSSEC:
+ case SO_RXQ_OVFL:
+ case SO_WIFI_STATUS:
+ case SO_NOFCS:
+ case SO_SELECT_ERR_QUEUE:
+ return true;
+ }
+
+ /* SO_OOBINLINE is not supported, let's avoid the related mess */
+ /* SO_ATTACH_FILTER, SO_ATTACH_BPF, SO_ATTACH_REUSEPORT_CBPF,
+ * SO_DETACH_REUSEPORT_BPF, SO_DETACH_FILTER, SO_LOCK_FILTER,
+ * we must be careful with subflows
+ */
+ /* SO_ATTACH_REUSEPORT_EBPF is not supported, at it checks
+ * explicitly the sk_protocol field
+ */
+ /* SO_PEEK_OFF is unsupported, as it is for plain TCP */
+ /* SO_MAX_PACING_RATE is unsupported, we must be careful with subflows */
+ /* SO_CNX_ADVICE is currently unsupported, could possibly be relevant,
+ * but likely needs careful design
+ */
+ /* SO_ZEROCOPY is currently unsupported, TODO in sndmsg */
+ /* SO_TXTIME is currently unsupported */
+ return false;
+ }
+ if (level == SOL_IP) {
+ switch (optname) {
+ /* should work fine */
+ case IP_FREEBIND:
+ case IP_TRANSPARENT:
+
+ /* the following are control cmsg related */
+ case IP_PKTINFO:
+ case IP_RECVTTL:
+ case IP_RECVTOS:
+ case IP_RECVOPTS:
+ case IP_RETOPTS:
+ case IP_PASSSEC:
+ case IP_RECVORIGDSTADDR:
+ case IP_CHECKSUM:
+ case IP_RECVFRAGSIZE:
+
+ /* common stuff that need some love */
+ case IP_TOS:
+ case IP_TTL:
+ case IP_BIND_ADDRESS_NO_PORT:
+ case IP_MTU_DISCOVER:
+ case IP_RECVERR:
+
+ /* possibly less common may deserve some love */
+ case IP_MINTTL:
+
+ /* the following is apparently a no-op for plain TCP */
+ case IP_RECVERR_RFC4884:
+ return true;
+ }
+
+ /* IP_OPTIONS is not supported, needs subflow care */
+ /* IP_HDRINCL, IP_NODEFRAG are not supported, RAW specific */
+ /* IP_MULTICAST_TTL, IP_MULTICAST_LOOP, IP_UNICAST_IF,
+ * IP_ADD_MEMBERSHIP, IP_ADD_SOURCE_MEMBERSHIP, IP_DROP_MEMBERSHIP,
+ * IP_DROP_SOURCE_MEMBERSHIP, IP_BLOCK_SOURCE, IP_UNBLOCK_SOURCE,
+ * MCAST_JOIN_GROUP, MCAST_LEAVE_GROUP MCAST_JOIN_SOURCE_GROUP,
+ * MCAST_LEAVE_SOURCE_GROUP, MCAST_BLOCK_SOURCE, MCAST_UNBLOCK_SOURCE,
+ * MCAST_MSFILTER, IP_MULTICAST_ALL are not supported, better not deal
+ * with mcast stuff
+ */
+ /* IP_IPSEC_POLICY, IP_XFRM_POLICY are nut supported, unrelated here */
+ return false;
+ }
+ if (level == SOL_IPV6) {
+ switch (optname) {
+ case IPV6_V6ONLY:
+
+ /* the following are control cmsg related */
+ case IPV6_RECVPKTINFO:
+ case IPV6_2292PKTINFO:
+ case IPV6_RECVHOPLIMIT:
+ case IPV6_2292HOPLIMIT:
+ case IPV6_RECVRTHDR:
+ case IPV6_2292RTHDR:
+ case IPV6_RECVHOPOPTS:
+ case IPV6_2292HOPOPTS:
+ case IPV6_RECVDSTOPTS:
+ case IPV6_2292DSTOPTS:
+ case IPV6_RECVTCLASS:
+ case IPV6_FLOWINFO:
+ case IPV6_RECVPATHMTU:
+ case IPV6_RECVORIGDSTADDR:
+ case IPV6_RECVFRAGSIZE:
+
+ /* the following ones need some love but are quite common */
+ case IPV6_TCLASS:
+ case IPV6_TRANSPARENT:
+ case IPV6_FREEBIND:
+ case IPV6_PKTINFO:
+ case IPV6_2292PKTOPTIONS:
+ case IPV6_UNICAST_HOPS:
+ case IPV6_MTU_DISCOVER:
+ case IPV6_MTU:
+ case IPV6_RECVERR:
+ case IPV6_FLOWINFO_SEND:
+ case IPV6_FLOWLABEL_MGR:
+ case IPV6_MINHOPCOUNT:
+ case IPV6_DONTFRAG:
+ case IPV6_AUTOFLOWLABEL:
+
+ /* the following one is a no-op for plain TCP */
+ case IPV6_RECVERR_RFC4884:
+ return true;
+ }
+
+ /* IPV6_HOPOPTS, IPV6_RTHDRDSTOPTS, IPV6_RTHDR, IPV6_DSTOPTS are
+ * not supported
+ */
+ /* IPV6_MULTICAST_HOPS, IPV6_MULTICAST_LOOP, IPV6_UNICAST_IF,
+ * IPV6_MULTICAST_IF, IPV6_ADDRFORM,
+ * IPV6_ADD_MEMBERSHIP, IPV6_DROP_MEMBERSHIP, IPV6_JOIN_ANYCAST,
+ * IPV6_LEAVE_ANYCAST, IPV6_MULTICAST_ALL, MCAST_JOIN_GROUP, MCAST_LEAVE_GROUP,
+ * MCAST_JOIN_SOURCE_GROUP, MCAST_LEAVE_SOURCE_GROUP,
+ * MCAST_BLOCK_SOURCE, MCAST_UNBLOCK_SOURCE, MCAST_MSFILTER
+ * are not supported better not deal with mcast
+ */
+ /* IPV6_ROUTER_ALERT, IPV6_ROUTER_ALERT_ISOLATE are not supported, since are evil */
+
+ /* IPV6_IPSEC_POLICY, IPV6_XFRM_POLICY are not supported */
+ /* IPV6_ADDR_PREFERENCES is not supported, we must be careful with subflows */
+ return false;
+ }
+ if (level == SOL_TCP) {
+ switch (optname) {
+ /* the following are no-op or should work just fine */
+ case TCP_THIN_DUPACK:
+ case TCP_DEFER_ACCEPT:
+
+ /* the following need some love */
+ case TCP_MAXSEG:
+ case TCP_NODELAY:
+ case TCP_THIN_LINEAR_TIMEOUTS:
+ case TCP_CONGESTION:
+ case TCP_ULP:
+ case TCP_CORK:
+ case TCP_KEEPIDLE:
+ case TCP_KEEPINTVL:
+ case TCP_KEEPCNT:
+ case TCP_SYNCNT:
+ case TCP_SAVE_SYN:
+ case TCP_LINGER2:
+ case TCP_WINDOW_CLAMP:
+ case TCP_QUICKACK:
+ case TCP_USER_TIMEOUT:
+ case TCP_TIMESTAMP:
+ case TCP_NOTSENT_LOWAT:
+ case TCP_TX_DELAY:
+ return true;
+ }
+
+ /* TCP_MD5SIG, TCP_MD5SIG_EXT are not supported, MD5 is not compatible with MPTCP */
+
+ /* TCP_REPAIR, TCP_REPAIR_QUEUE, TCP_QUEUE_SEQ, TCP_REPAIR_OPTIONS,
+ * TCP_REPAIR_WINDOW are not supported, better avoid this mess
+ */
+ /* TCP_FASTOPEN_KEY, TCP_FASTOPEN TCP_FASTOPEN_CONNECT, TCP_FASTOPEN_NO_COOKIE,
+ * are not supported fastopen is currently unsupported
+ */
+ /* TCP_INQ is currently unsupported, needs some recvmsg work */
+ }
+ return false;
+}
+
int mptcp_setsockopt(struct sock *sk, int level, int optname,
sockptr_t optval, unsigned int optlen)
{
@@ -90,6 +303,9 @@ int mptcp_setsockopt(struct sock *sk, int level, int optname,
pr_debug("msk=%p", msk);
+ if (!mptcp_supported_sockopt(level, optname))
+ return -ENOPROTOOPT;
+
if (level == SOL_SOCKET)
return mptcp_setsockopt_sol_socket(msk, optname, optval, optlen);