releases/5.0.3/sctp-remove-sched-init-from-sctp_stream_init.patch

   1 From foo@baz Thu Mar 14 23:19:55 PDT 2019
   2 From: Xin Long <lucien.xin@gmail.com>
   3 Date: Fri, 8 Mar 2019 15:49:16 +0800
   4 Subject: sctp: remove sched init from sctp_stream_init
   5
   6 From: Xin Long <lucien.xin@gmail.com>
   7
   8 [ Upstream commit 2e990dfd13974d9eae493006f42ffb48707970ef ]
   9
  10 syzbot reported a NULL-ptr deref caused by that sched->init() in
  11 sctp_stream_init() set stream->rr_next = NULL.
  12
  13   kasan: GPF could be caused by NULL-ptr deref or user memory access
  14   RIP: 0010:sctp_sched_rr_dequeue+0xd3/0x170 net/sctp/stream_sched_rr.c:141
  15   Call Trace:
  16     sctp_outq_dequeue_data net/sctp/outqueue.c:90 [inline]
  17     sctp_outq_flush_data net/sctp/outqueue.c:1079 [inline]
  18     sctp_outq_flush+0xba2/0x2790 net/sctp/outqueue.c:1205
  19
  20 All sched info is saved in sout->ext now, in sctp_stream_init()
  21 sctp_stream_alloc_out() will not change it, there's no need to
  22 call sched->init() again, since sctp_outq_init() has already
  23 done it.
  24
  25 Fixes: 5bbbbe32a431 ("sctp: introduce stream scheduler foundations")
  26 Reported-by: syzbot+4c9934f20522c0efd657@syzkaller.appspotmail.com
  27 Signed-off-by: Xin Long <lucien.xin@gmail.com>
  28 Acked-by: Neil Horman <nhorman@tuxdriver.com>
  29 Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
  30 Signed-off-by: David S. Miller <davem@davemloft.net>
  31 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  32 ---
  33  net/sctp/stream.c |    2 --
  34  1 file changed, 2 deletions(-)
  35
  36 --- a/net/sctp/stream.c
  37 +++ b/net/sctp/stream.c
  38 @@ -230,8 +230,6 @@ int sctp_stream_init(struct sctp_stream
  39         for (i = 0; i < stream->outcnt; i++)
  40                 SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
  41
  42 -       sched->init(stream);
  43 -
  44  in:
  45         sctp_stream_interleave_init(stream);
  46         if (!incnt)