mptcp: handle consistently DSS corruption

commit e32d262c89e2b22cb0640223f953b548617ed8a6 upstream.

Bugged peer implementation can send corrupted DSS options, consistently
hitting a few warning in the data path. Use DEBUG_NET assertions, to
avoid the splat on some builds and handle consistently the error, dumping
related MIBs and performing fallback and/or reset according to the
subflow type.

Fixes: 6771bfd9ee ("mptcp: update mptcp ack sequence from work queue")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241008-net-mptcp-fallback-fixes-v1-1-c6fb8e93e551@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Paolo Abeni 2024-10-08 13:04:52 +02:00 committed by Greg Kroah-Hartman
parent 143ffa7878
commit b8be15d1ae
4 changed files with 28 additions and 4 deletions

View file

@ -26,6 +26,8 @@ static const struct snmp_mib mptcp_snmp_list[] = {
SNMP_MIB_ITEM("MPJoinAckRx", MPTCP_MIB_JOINACKRX), SNMP_MIB_ITEM("MPJoinAckRx", MPTCP_MIB_JOINACKRX),
SNMP_MIB_ITEM("MPJoinAckHMacFailure", MPTCP_MIB_JOINACKMAC), SNMP_MIB_ITEM("MPJoinAckHMacFailure", MPTCP_MIB_JOINACKMAC),
SNMP_MIB_ITEM("DSSNotMatching", MPTCP_MIB_DSSNOMATCH), SNMP_MIB_ITEM("DSSNotMatching", MPTCP_MIB_DSSNOMATCH),
SNMP_MIB_ITEM("DSSCorruptionFallback", MPTCP_MIB_DSSCORRUPTIONFALLBACK),
SNMP_MIB_ITEM("DSSCorruptionReset", MPTCP_MIB_DSSCORRUPTIONRESET),
SNMP_MIB_ITEM("InfiniteMapTx", MPTCP_MIB_INFINITEMAPTX), SNMP_MIB_ITEM("InfiniteMapTx", MPTCP_MIB_INFINITEMAPTX),
SNMP_MIB_ITEM("InfiniteMapRx", MPTCP_MIB_INFINITEMAPRX), SNMP_MIB_ITEM("InfiniteMapRx", MPTCP_MIB_INFINITEMAPRX),
SNMP_MIB_ITEM("DSSNoMatchTCP", MPTCP_MIB_DSSTCPMISMATCH), SNMP_MIB_ITEM("DSSNoMatchTCP", MPTCP_MIB_DSSTCPMISMATCH),

View file

@ -19,6 +19,8 @@ enum linux_mptcp_mib_field {
MPTCP_MIB_JOINACKRX, /* Received an ACK + MP_JOIN */ MPTCP_MIB_JOINACKRX, /* Received an ACK + MP_JOIN */
MPTCP_MIB_JOINACKMAC, /* HMAC was wrong on ACK + MP_JOIN */ MPTCP_MIB_JOINACKMAC, /* HMAC was wrong on ACK + MP_JOIN */
MPTCP_MIB_DSSNOMATCH, /* Received a new mapping that did not match the previous one */ MPTCP_MIB_DSSNOMATCH, /* Received a new mapping that did not match the previous one */
MPTCP_MIB_DSSCORRUPTIONFALLBACK,/* DSS corruption detected, fallback */
MPTCP_MIB_DSSCORRUPTIONRESET, /* DSS corruption detected, MPJ subflow reset */
MPTCP_MIB_INFINITEMAPTX, /* Sent an infinite mapping */ MPTCP_MIB_INFINITEMAPTX, /* Sent an infinite mapping */
MPTCP_MIB_INFINITEMAPRX, /* Received an infinite mapping */ MPTCP_MIB_INFINITEMAPRX, /* Received an infinite mapping */
MPTCP_MIB_DSSTCPMISMATCH, /* DSS-mapping did not map with TCP's sequence numbers */ MPTCP_MIB_DSSTCPMISMATCH, /* DSS-mapping did not map with TCP's sequence numbers */

View file

@ -620,6 +620,18 @@ static bool mptcp_check_data_fin(struct sock *sk)
return ret; return ret;
} }
static void mptcp_dss_corruption(struct mptcp_sock *msk, struct sock *ssk)
{
if (READ_ONCE(msk->allow_infinite_fallback)) {
MPTCP_INC_STATS(sock_net(ssk),
MPTCP_MIB_DSSCORRUPTIONFALLBACK);
mptcp_do_fallback(ssk);
} else {
MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DSSCORRUPTIONRESET);
mptcp_subflow_reset(ssk);
}
}
static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk, static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk,
struct sock *ssk, struct sock *ssk,
unsigned int *bytes) unsigned int *bytes)
@ -692,10 +704,16 @@ static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk,
moved += len; moved += len;
seq += len; seq += len;
if (WARN_ON_ONCE(map_remaining < len)) if (unlikely(map_remaining < len)) {
break; DEBUG_NET_WARN_ON_ONCE(1);
mptcp_dss_corruption(msk, ssk);
}
} else { } else {
WARN_ON_ONCE(!fin); if (unlikely(!fin)) {
DEBUG_NET_WARN_ON_ONCE(1);
mptcp_dss_corruption(msk, ssk);
}
sk_eat_skb(ssk, skb); sk_eat_skb(ssk, skb);
done = true; done = true;
} }

View file

@ -944,8 +944,10 @@ static bool skb_is_fully_mapped(struct sock *ssk, struct sk_buff *skb)
unsigned int skb_consumed; unsigned int skb_consumed;
skb_consumed = tcp_sk(ssk)->copied_seq - TCP_SKB_CB(skb)->seq; skb_consumed = tcp_sk(ssk)->copied_seq - TCP_SKB_CB(skb)->seq;
if (WARN_ON_ONCE(skb_consumed >= skb->len)) if (unlikely(skb_consumed >= skb->len)) {
DEBUG_NET_WARN_ON_ONCE(1);
return true; return true;
}
return skb->len - skb_consumed <= subflow->map_data_len - return skb->len - skb_consumed <= subflow->map_data_len -
mptcp_subflow_get_map_offset(subflow); mptcp_subflow_get_map_offset(subflow);