From ce950f1050cece5e406a5cde723c69bba60e1b26 Mon Sep 17 00:00:00 2001 From: Neil Horman Date: Thu, 13 Jun 2019 06:35:59 -0400 Subject: [PATCH] sctp: Free cookie before we memdup a new one 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 v4->v5 remove cut line Signed-off-by: Neil Horman Reported-by: syzbot+f7e9153b037eac9b1df8@syzkaller.appspotmail.com CC: Marcelo Ricardo Leitner CC: Xin Long CC: "David S. Miller" CC: netdev@vger.kernel.org Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- 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 f17908f5c4f3c..9b0e5b0d701ad 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -2583,6 +2583,8 @@ do_addr_param: 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 @@ do_addr_param: 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 @@ do_addr_param: 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 @@ do_addr_param: 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) -- 2.39.2