This is a note to let you know that I've just added the patch titled
dccp: don't duplicate ccid when cloning dccp sock
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dccp-don-t-duplicate-ccid-when-cloning-dccp-sock.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d273fe35f528aeaa58b1a5ac5d3e4900c876da7c
Author: Lin, Zhenpeng <zplin@xxxxxxx>
Date: Wed Sep 8 03:40:59 2021 +0000
dccp: don't duplicate ccid when cloning dccp sock
[ Upstream commit d9ea761fdd197351890418acd462c51f241014a7 ]
Commit 2677d2067731 ("dccp: don't free ccid2_hc_tx_sock ...") fixed
a UAF but reintroduced CVE-2017-6074.
When the sock is cloned, two dccps_hc_tx_ccid will reference to the
same ccid. So one can free the ccid object twice from two socks after
cloning.
This issue was found by "Hadar Manor" as well and assigned with
CVE-2020-16119, which was fixed in Ubuntu's kernel. So here I port
the patch from Ubuntu to fix it.
The patch prevents cloned socks from referencing the same ccid.
Fixes: 2677d2067731410 ("dccp: don't free ccid2_hc_tx_sock ...")
Signed-off-by: Zhenpeng Lin <zplin@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index 25187528c308..1f352d669c94 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -94,6 +94,8 @@ struct sock *dccp_create_openreq_child(const struct sock *sk,
newdp->dccps_role = DCCP_ROLE_SERVER;
newdp->dccps_hc_rx_ackvec = NULL;
newdp->dccps_service_list = NULL;
+ newdp->dccps_hc_rx_ccid = NULL;
+ newdp->dccps_hc_tx_ccid = NULL;
newdp->dccps_service = dreq->dreq_service;
newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo;
newdp->dccps_timestamp_time = dreq->dreq_timestamp_time;
