sctp: check and update stream->out_curr when allocating stream_out

Now when using stream reconfig to add out streams, stream->out
will get re-allocated, and all old streams' information will
be copied to the new ones and the old ones will be freed.

So without stream->out_curr updated, next time when trying to
send from stream->out_curr stream, a panic would be caused.

This patch is to check and update stream->out_curr when
allocating stream_out.

v1->v2:
  - define fa_index() to get elem index from stream->out_curr.
v2->v3:
  - repost with no change.

Fixes: 5bbbbe32a4 ("sctp: introduce stream scheduler foundations")
Reported-by: Ying Xu <yinxu@redhat.com>
Reported-by: syzbot+e33a3a138267ca119c7d@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Xin Long 2019-02-04 03:27:58 +08:00 committed by David S. Miller
parent 8dfb8d2cce
commit cfe4bd7a25

View File

@ -84,6 +84,19 @@ static void fa_zero(struct flex_array *fa, size_t index, size_t count)
}
}
static size_t fa_index(struct flex_array *fa, void *elem, size_t count)
{
size_t index = 0;
while (count--) {
if (elem == flex_array_get(fa, index))
break;
index++;
}
return index;
}
/* Migrates chunks from stream queues to new stream queues if needed,
* but not across associations. Also, removes those chunks to streams
* higher than the new max.
@ -147,6 +160,13 @@ static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt,
if (stream->out) {
fa_copy(out, stream->out, 0, min(outcnt, stream->outcnt));
if (stream->out_curr) {
size_t index = fa_index(stream->out, stream->out_curr,
stream->outcnt);
BUG_ON(index == stream->outcnt);
stream->out_curr = flex_array_get(out, index);
}
fa_free(stream->out);
}