sctp: fix the processing for INIT chunk

mainline inclusion
from mainline
commit eae57839
bugzilla: 182989 https://gitee.com/openeuler/kernel/issues/I4DDEL
CVE: CVE-2021-3772

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=eae5783908042a762c24e1bd11876edb91d314b1



--------------------------------

This patch fixes the problems below:

1. In non-shutdown_ack_sent states: in sctp_sf_do_5_1B_init() and
   sctp_sf_do_5_2_2_dupinit():

  chunk length check should be done before any checks that may cause
  to send abort, as making packet for abort will access the init_tag
  from init_hdr in sctp_ootb_pkt_new().

2. In shutdown_ack_sent state: in sctp_sf_do_9_2_reshutack():

  The same checks as does in sctp_sf_do_5_2_2_dupinit() is needed
  for sctp_sf_do_9_2_reshutack().

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>

Conflicts:
	net/sctp/sm_statefuns.c
Reviewed-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: weiyang wang <wangweiyang2@huawei.com>

Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>