| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 133/172] sctp: check af before verify address in sctp_addr_id2transport | Date | Mon, 3 Jul 2017 15:35:13 +0200 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Xin Long <lucien.xin@gmail.com>
[ 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 <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/sctp/socket.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -239,7 +239,7 @@ static struct sctp_transport *sctp_addr_ 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,
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