Re: [PATCH v2] [net] Free cookie before we memdup a new one
From: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Date: 2019-06-11 11:44:38
Also in:
linux-sctp
On Tue, Jun 11, 2019 at 07:21:28AM -0400, Neil Horman 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. --- Change notes v1->v2 update subsystem tag in subject (davem) repeat kfree check for peer_random and peer_hmacs (xin)
They are actually 4 vars. The 4th one being peer_chunks. And a syzkaller Fixes tag would be welcomed as well, so that if someone backports the fix for it will have a hint to backport this patch also.
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 | 6 ++++++ 1 file changed, 6 insertions(+)diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index f17908f5c4f3..0992ec0395f8 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) {-- 2.20.1