4.16-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 d625329b06e46bd20baf9ee40847d11982569204 ]
Since sctp ipv6 socket also supports v4 addrs, it's possible to compare two v4 addrs in pf v6 .cmp_addr, sctp_inet6_cmp_addr.
However after Commit 1071ec9d453a ("sctp: do not check port in sctp_inet6_cmp_addr"), it no longer calls af1->cmp_addr, which in this case is sctp_v4_cmp_addr, but calls __sctp_v6_cmp_addr where it handles them as two v6 addrs. It would cause a out of bounds crash.
syzbot found this crash when trying to bind two v4 addrs to a v6 socket.
This patch fixes it by adding the process for two v4 addrs in sctp_inet6_cmp_addr.
Fixes: 1071ec9d453a ("sctp: do not check port in sctp_inet6_cmp_addr") Reported-by: syzbot+cd494c1dd681d4d93ebb@syzkaller.appspotmail.com Signed-off-by: Xin Long lucien.xin@gmail.com Acked-by: Neil Horman nhorman@tuxdriver.com Acked-by: Marcelo Ricardo Leitner marcelo.leitner@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sctp/ipv6.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/net/sctp/ipv6.c +++ b/net/sctp/ipv6.c @@ -866,6 +866,9 @@ static int sctp_inet6_cmp_addr(const uni if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2)) return 1;
+ if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET) + return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr; + return __sctp_v6_cmp_addr(addr1, addr2); }