From: Xin Long Date: Tue, 7 Feb 2017 12:56:08 +0000 (+0800) Subject: sctp: check af before verify address in sctp_addr_id2transport X-Git-Tag: release-20171130_firefly~4^2~100^2^2~2^2~21 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=db1323b77c2b35e5633867fc5e8a79c65f130119;p=firefly-linux-kernel-4.4.55.git sctp: check af before verify address in sctp_addr_id2transport [ Upstream commit 912964eacb111551db73429719eb5fadcab0ff8a ] Commit 6f29a1306131 ("sctp: sctp_addr_id2transport should verify the addr before looking up assoc") invoked sctp_verify_addr to verify the addr. But it didn't check af variable beforehand, once users pass an address with family = 0 through sockopt, sctp_get_af_specific will return NULL and NULL pointer dereference will be caused by af->sockaddr_len. This patch is to fix it by returning NULL if af variable is NULL. Fixes: 6f29a1306131 ("sctp: sctp_addr_id2transport should verify the addr before looking up assoc") Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 956141b71619..3ebf3b652d60 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -239,7 +239,7 @@ static struct sctp_transport *sctp_addr_id2transport(struct sock *sk, union sctp_addr *laddr = (union sctp_addr *)addr; struct sctp_transport *transport; - if (sctp_verify_addr(sk, laddr, af->sockaddr_len)) + if (!af || sctp_verify_addr(sk, laddr, af->sockaddr_len)) return NULL; addr_asoc = sctp_endpoint_lookup_assoc(sctp_sk(sk)->ep,