Re: [PATCH] Free cookie before we memdup a new one
From: Xin Long <lucien.xin@gmail.com>
Date: 2019-06-10 16:54:36
Also in:
linux-sctp
On Tue, Jun 11, 2019 at 12:35 AM Neil Horman [off-list ref] wrote:
Based on comments from Xin, even after fixes for our recent syzbot report of cookie memory leaks, its possible to get a resend of an INIT chunk which would lead to us leaking cookie memory. To ensure that we don't leak cookie memory, free any previously allocated cookie first.
Hi, Neil, I think we should also do the same thing to the other 2 kmemdups in sctp_process_param(): asoc->peer.peer_random asoc->peer.peer_hmacs
quoted hunk ↗ jump to hunk
Signed-off-by: Neil Horman <nhorman@tuxdriver.com> CC: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> CC: Xin Long <lucien.xin@gmail.com> CC: "David S. Miller" <davem@davemloft.net> CC: netdev@vger.kernel.org --- net/sctp/sm_make_chunk.c | 2 ++ 1 file changed, 2 insertions(+)diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index f17908f5c4f3..21f7faf032e5 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c@@ -2583,6 +2583,8 @@ static int sctp_process_param(struct sctp_association *asoc, case SCTP_PARAM_STATE_COOKIE: asoc->peer.cookie_len = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); + if (asoc->peer.cookie) + kfree(asoc->peer.cookie); asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp); if (!asoc->peer.cookie) retval = 0; --2.20.1