From: Xin Long <lucien....@gmail.com>
Date: Tue, 12 Feb 2019 18:51:01 +0800
> In sctp_stream_init(), after sctp_stream_outq_migrate() freed the
> surplus streams' ext, but sctp_stream_alloc_out() returns -ENOMEM,
> stream->outcnt will not be set to 'outcnt'.
>
> With the bigger value on stream->outcnt, when closing the assoc and
> freeing its streams, the ext of those surplus streams will be freed
> again since those stream exts were not set to NULL after freeing in
> sctp_stream_outq_migrate(). Then the invalid-free issue reported by
> syzbot would be triggered.
>
> We fix it by simply setting them to NULL after freeing.
>
> Fixes: 5bbbbe32a431 ("sctp: introduce stream scheduler foundations")
> Reported-by: syzbot+58e480e7b28f2d890...@syzkaller.appspotmail.com
> Signed-off-by: Xin Long <lucien....@gmail.com>
Also applied and queued up for -stable, thanks.
