linux-kernel - [PATCH] platform/chrome: cros_ec

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20221207040049.1.I1864b6a7ee98824118b93677868d22d3750f439b@changeid>
Date:   Wed,  7 Dec 2022 04:01:08 +0000
From:   Victor Ding <victording@...omium.org>
To:     linux-kernel@...r.kernel.org, chrome-platform@...ts.linux.dev
Cc:     tinghan.shen@...iatek.com, gustavoars@...nel.org,
        sebastian.reichel@...labora.com, dnojiri@...omium.org,
        bleung@...omium.org, lee.jones@...aro.org, pmalani@...omium.org,
        groeck@...omium.org, tzungbi@...nel.org,
        gregkh@...uxfoundation.org, dustin@...ett.net,
        Victor Ding <victording@...omium.org>
Subject: [PATCH] platform/chrome: cros_ec_typec: zero out stale pointers

`cros_typec_get_switch_handles` allocates several pointers when
obtaining four handles. These pointers are all freed if failing to
obtain any of the four handles; therefore, pointers in `port` becomes
stale. The stale pointers eventually cause use-after-free or double in
later code paths.

This patch proposes to elimite these stale pointers by zeroing them out
right after they are freed.

Signed-off-by: Victor Ding <victording@...omium.org>
---

 drivers/platform/chrome/cros_ec_typec.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
index 2a7ff14dc37e..59de4ce01fab 100644
--- a/drivers/platform/chrome/cros_ec_typec.c
+++ b/drivers/platform/chrome/cros_ec_typec.c
@@ -173,10 +173,13 @@ static int cros_typec_get_switch_handles(struct cros_typec_port *port,
 
 role_sw_err:
 	typec_switch_put(port->ori_sw);
+	port->ori_sw = NULL;
 ori_sw_err:
 	typec_retimer_put(port->retimer);
+	port->retimer = NULL;
 retimer_sw_err:
 	typec_mux_put(port->mux);
+	port->mux = NULL;
 mux_err:
 	return -ENODEV;
 }
-- 
2.39.0.rc0.267.gcb52ba06e7-goog