From: Xin Long <lucien....@gmail.com>
Date: Thu, 10 May 2018 17:34:13 +0800
> In Commit 1f45f78f8e51 ("sctp: allow GSO frags to access the chunk too"),
> it held the chunk in sctp_ulpevent_make_rcvmsg to access it safely later
> in recvmsg. However, it also added sctp_chunk_put in fail_mark err path,
> which is only triggered before holding the chunk.
>
> syzbot reported a use-after-free crash happened on this err path, where
> it shouldn't call sctp_chunk_put.
>
> This patch simply removes this call.
>
> Fixes: 1f45f78f8e51 ("sctp: allow GSO frags to access the chunk too")
> Reported-by: syzbot+141d898c5f24489db...@syzkaller.appspotmail.com
> Signed-off-by: Xin Long <lucien....@gmail.com>
Applied and queued up for -stable.
