From: Neil Horman <nhorman@tuxdriver.com>
Date: Thu, 13 Jun 2019 06:35:59 -0400
Subject: sctp: Free cookie before we memdup a new one
Git-commit: ce950f1050cece5e406a5cde723c69bba60e1b26
Patch-mainline: 5.2-rc6
References: networking-stable-19_06_18
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 <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
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
net/sctp/sm_make_chunk.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -2590,6 +2590,8 @@ do_addr_param:
case SCTP_PARAM_STATE_COOKIE:
asoc->peer.cookie_len =
ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
+ 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;
@@ -2654,6 +2656,8 @@ 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) {
@@ -2667,6 +2671,8 @@ 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) {
@@ -2682,6 +2688,8 @@ 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)