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From:   Prashant Malani <pmalani@chromium.org>
To:     linux-kernel@vger.kernel.org
Cc:     heikki.krogerus@linux.intel.com,
        Prashant Malani <pmalani@chromium.org>,
        Benson Leung <bleung@chromium.org>,
        Enric Balletbo i Serra <enric.balletbo@collabora.com>,
        Guenter Roeck <groeck@chromium.org>,
        Mark Brown <broonie@kernel.org>,
        Pi-Hsun Shih <pihsun@chromium.org>
Subject: [PATCH 2/7] platform/chrome: cros_ec_typec: Fix remove partner logic
Date:   Wed, 21 Oct 2020 13:53:11 -0700
Message-Id: <20201021205317.708008-3-pmalani@chromium.org>
In-Reply-To: <20201021205317.708008-1-pmalani@chromium.org>
References: <20201021205317.708008-1-pmalani@chromium.org>
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The cros_unregister_ports() function can be called in situations where
the partner has not been registered yet, and so its related data
structures would not have been initialized. Calling
cros_typec_remove_partner() in such a situation can lead to null pointer
dereferences. So, only call cros_typec_remove_partner() if there is a
valid registered partner pointer.

Signed-off-by: Prashant Malani <pmalani@chromium.org>
---
 drivers/platform/chrome/cros_ec_typec.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
index 49083e21317d..2665d8125910 100644
--- a/drivers/platform/chrome/cros_ec_typec.c
+++ b/drivers/platform/chrome/cros_ec_typec.c
@@ -190,7 +190,10 @@ static void cros_unregister_ports(struct cros_typec_data *typec)
 	for (i = 0; i < typec->num_ports; i++) {
 		if (!typec->ports[i])
 			continue;
-		cros_typec_remove_partner(typec, i);
+
+		if (typec->ports[i]->partner)
+			cros_typec_remove_partner(typec, i);
+
 		usb_role_switch_put(typec->ports[i]->role_sw);
 		typec_switch_put(typec->ports[i]->ori_sw);
 		typec_mux_put(typec->ports[i]->mux);
-- 
2.29.0.rc1.297.gfa9743e501-goog