4.19-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 2e990dfd13974d9eae493006f42ffb48707970ef ]
syzbot reported a NULL-ptr deref caused by that sched->init() in sctp_stream_init() set stream->rr_next = NULL.
kasan: GPF could be caused by NULL-ptr deref or user memory access RIP: 0010:sctp_sched_rr_dequeue+0xd3/0x170 net/sctp/stream_sched_rr.c:141 Call Trace: sctp_outq_dequeue_data net/sctp/outqueue.c:90 [inline] sctp_outq_flush_data net/sctp/outqueue.c:1079 [inline] sctp_outq_flush+0xba2/0x2790 net/sctp/outqueue.c:1205
All sched info is saved in sout->ext now, in sctp_stream_init() sctp_stream_alloc_out() will not change it, there's no need to call sched->init() again, since sctp_outq_init() has already done it.
Fixes: 5bbbbe32a431 ("sctp: introduce stream scheduler foundations") Reported-by: syzbot+4c9934f20522c0efd657@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/stream.c | 2 -- 1 file changed, 2 deletions(-)
--- a/net/sctp/stream.c +++ b/net/sctp/stream.c @@ -230,8 +230,6 @@ int sctp_stream_init(struct sctp_stream for (i = 0; i < stream->outcnt; i++) SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
- sched->init(stream); - in: sctp_stream_interleave_init(stream); if (!incnt)