From c79fcc27be90b308b3fa90811aefafdd4078668c Mon Sep 17 00:00:00 2001 From: Tung Nguyen Date: Tue, 8 Mar 2022 02:11:59 +0000 Subject: [PATCH] tipc: fix incorrect order of state message data sanity check When receiving a state message, function tipc_link_validate_msg() is called to validate its header portion. Then, its data portion is validated before it can be accessed correctly. However, current data sanity check is done after the message header is accessed to update some link variables. This commit fixes this issue by moving the data sanity check to the beginning of state message handling and right after the header sanity check. Fixes: 9aa422ad3266 ("tipc: improve size validations for received domain records") Acked-by: Jon Maloy Signed-off-by: Tung Nguyen Link: https://lore.kernel.org/r/20220308021200.9245-1-tung.q.nguyen@dektech.com.au Signed-off-by: Jakub Kicinski --- net/tipc/link.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/net/tipc/link.c b/net/tipc/link.c index 1e14d7f8f28f..e260c0d557f5 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -2286,6 +2286,11 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb, break; case STATE_MSG: + /* Validate Gap ACK blocks, drop if invalid */ + glen = tipc_get_gap_ack_blks(&ga, l, hdr, true); + if (glen > dlen) + break; + l->rcv_nxt_state = msg_seqno(hdr) + 1; /* Update own tolerance if peer indicates a non-zero value */ @@ -2311,10 +2316,6 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb, break; } - /* Receive Gap ACK blocks from peer if any */ - glen = tipc_get_gap_ack_blks(&ga, l, hdr, true); - if(glen > dlen) - break; tipc_mon_rcv(l->net, data + glen, dlen - glen, l->addr, &l->mon_state, l->bearer_id);