[PATCH v4 net] sctp: Free cookie before we memdup a new one
From: Neil Horman <nhorman@tuxdriver.com>
Date: 2019-06-12 00:38:30
Also in:
linux-sctp
Subsystem:
networking [general], sctp protocol, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Marcelo Ricardo Leitner, Xin Long, Linus Torvalds
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. --- Change notes v1->v2 update subsystem tag in subject (davem) repeat kfree check for peer_random and peer_hmacs (xin) v2->v3 net->sctp also free peer_chunks v3->v4 fix subject tags Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: syzbot+f7e9153b037eac9b1df8@syzkaller.appspotmail.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 | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index f17908f5c4f3..9b0e5b0d701a 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;
@@ -2647,6 +2649,8 @@ static int sctp_process_param(struct sctp_association *asoc, goto fall_through; /* Save peer's random parameter */ + if (asoc->peer.peer_random) + kfree(asoc->peer.peer_random); asoc->peer.peer_random = kmemdup(param.p, ntohs(param.p->length), gfp); if (!asoc->peer.peer_random) {
@@ -2660,6 +2664,8 @@ static int sctp_process_param(struct sctp_association *asoc, goto fall_through; /* Save peer's HMAC list */ + if (asoc->peer.peer_hmacs) + kfree(asoc->peer.peer_hmacs); asoc->peer.peer_hmacs = kmemdup(param.p, ntohs(param.p->length), gfp); if (!asoc->peer.peer_hmacs) {
@@ -2675,6 +2681,8 @@ static int sctp_process_param(struct sctp_association *asoc, if (!ep->auth_enable) goto fall_through; + if (asoc->peer.peer_chunks) + kfree(asoc->peer.peer_chunks); asoc->peer.peer_chunks = kmemdup(param.p, ntohs(param.p->length), gfp); if (!asoc->peer.peer_chunks)
--
2.20.1