4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Xin Long <lucien.xin@xxxxxxxxx>
[ Upstream commit 0ead60804b64f5bd6999eec88e503c6a1a242d41 ]
A size validation fix similar to that in Commit 50619dbf8db7 ("sctp: add
size validation when walking chunks") is also required in sctp_sf_ootb()
to address a crash reported by syzbot:
BUG: KMSAN: uninit-value in sctp_sf_ootb+0x7f5/0xce0 net/sctp/sm_statefuns.c:3712
sctp_sf_ootb+0x7f5/0xce0 net/sctp/sm_statefuns.c:3712
sctp_do_sm+0x181/0x93d0 net/sctp/sm_sideeffect.c:1166
sctp_endpoint_bh_rcv+0xc38/0xf90 net/sctp/endpointola.c:407
sctp_inq_push+0x2ef/0x380 net/sctp/inqueue.c:88
sctp_rcv+0x3831/0x3b20 net/sctp/input.c:243
sctp4_rcv+0x42/0x50 net/sctp/protocol.c:1159
ip_protocol_deliver_rcu+0xb51/0x13d0 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x336/0x500 net/ipv4/ip_input.c:233
Reported-by: syzbot+f0cbb34d39392f2746ca@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
Link: https://patch.msgid.link/a29ebb6d8b9f8affd0f9abb296faafafe10c17d8.1730223981.git.lucien.xin@xxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/sctp/sm_statefuns.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 8298f27e8de0d..0b44ad00dbb69 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -3652,7 +3652,7 @@ enum sctp_disposition sctp_sf_ootb(struct net *net,
}
ch = (struct sctp_chunkhdr *)ch_end;
- } while (ch_end < skb_tail_pointer(skb));
+ } while (ch_end + sizeof(*ch) < skb_tail_pointer(skb));
if (ootb_shut_ack)
return sctp_sf_shut_8_4_5(net, ep, asoc, type, arg, commands);
--
2.43.0
