From: Paolo Abeni pabeni@redhat.com
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: 6771bfd9ee24 ("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... Signed-off-by: Jakub Kicinski kuba@kernel.org [ Conflicts in mib.[ch], because commit 104125b82e5c ("mptcp: add mib for infinite map sending") is linked to a new feature, not available in this version. Resolving the conflicts is easy, simply adding the new lines declaring the new "DSS corruptions" MIB entries. Also removed in protocol.c and subflow.c all DEBUG_NET_WARN_ON_ONCE because they are not defined in this version: enough with the MIB counters that have been added in this commit. ] Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/mib.c | 2 ++ net/mptcp/mib.h | 2 ++ net/mptcp/protocol.c | 20 +++++++++++++++++--- net/mptcp/subflow.c | 2 +- 4 files changed, 22 insertions(+), 4 deletions(-)
diff --git a/net/mptcp/mib.c b/net/mptcp/mib.c index f4034e000f3e..44d083958d8e 100644 --- a/net/mptcp/mib.c +++ b/net/mptcp/mib.c @@ -23,6 +23,8 @@ static const struct snmp_mib mptcp_snmp_list[] = { SNMP_MIB_ITEM("MPJoinAckRx", MPTCP_MIB_JOINACKRX), SNMP_MIB_ITEM("MPJoinAckHMacFailure", MPTCP_MIB_JOINACKMAC), SNMP_MIB_ITEM("DSSNotMatching", MPTCP_MIB_DSSNOMATCH), + SNMP_MIB_ITEM("DSSCorruptionFallback", MPTCP_MIB_DSSCORRUPTIONFALLBACK), + SNMP_MIB_ITEM("DSSCorruptionReset", MPTCP_MIB_DSSCORRUPTIONRESET), SNMP_MIB_ITEM("InfiniteMapRx", MPTCP_MIB_INFINITEMAPRX), SNMP_MIB_ITEM("OFOQueueTail", MPTCP_MIB_OFOQUEUETAIL), SNMP_MIB_ITEM("OFOQueue", MPTCP_MIB_OFOQUEUE), diff --git a/net/mptcp/mib.h b/net/mptcp/mib.h index a9f43ff00b3c..0e17e1cebdbc 100644 --- a/net/mptcp/mib.h +++ b/net/mptcp/mib.h @@ -16,6 +16,8 @@ enum linux_mptcp_mib_field { MPTCP_MIB_JOINACKRX, /* Received an 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_DSSCORRUPTIONFALLBACK,/* DSS corruption detected, fallback */ + MPTCP_MIB_DSSCORRUPTIONRESET, /* DSS corruption detected, MPJ subflow reset */ MPTCP_MIB_INFINITEMAPRX, /* Received an infinite mapping */ MPTCP_MIB_OFOQUEUETAIL, /* Segments inserted into OoO queue tail */ MPTCP_MIB_OFOQUEUE, /* Segments inserted into OoO queue */ diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 24a21ff0cb8a..8558309a2d3f 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -457,6 +457,18 @@ static void mptcp_check_data_fin(struct sock *sk) } }
+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, struct sock *ssk, unsigned int *bytes) @@ -519,10 +531,12 @@ static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk, moved += len; seq += len;
- if (WARN_ON_ONCE(map_remaining < len)) - break; + if (unlikely(map_remaining < len)) + mptcp_dss_corruption(msk, ssk); } else { - WARN_ON_ONCE(!fin); + if (unlikely(!fin)) + mptcp_dss_corruption(msk, ssk); + sk_eat_skb(ssk, skb); done = true; } diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 0c020ca463f4..c3434069fb0a 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -702,7 +702,7 @@ static bool skb_is_fully_mapped(struct sock *ssk, struct sk_buff *skb) unsigned int skb_consumed;
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)) return true;
return skb->len - skb_consumed <= subflow->map_data_len -