sctp: remove sctp_chunk_put from fail_mark err path in sctp_ulpevent_make_rcvmsg

In Commit 1f45f78f8e ("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: 1f45f78f8e ("sctp: allow GSO frags to access the chunk too")
Reported-by: syzbot+141d898c5f24489db4aa@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>
This commit is contained in:
Xin Long 2018-05-10 17:34:13 +08:00 коммит произвёл David S. Miller
Родитель a577d868b7
Коммит 6910e25de2
1 изменённых файлов: 0 добавлений и 1 удалений

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@ -715,7 +715,6 @@ struct sctp_ulpevent *sctp_ulpevent_make_rcvmsg(struct sctp_association *asoc,
return event;
fail_mark:
sctp_chunk_put(chunk);
kfree_skb(skb);
fail:
return NULL;