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[3/8] usb: typec: ucsi: glink: check message data sizes

Message ID 20240416-ucsi-glink-altmode-v1-3-890db00877ac@linaro.org
State New
Headers show
Series usb: typec: ucsi: glink: merge in altmode support | expand

Commit Message

Dmitry Baryshkov April 16, 2024, 2:20 a.m. UTC 
The driver gets data from the DSP firmware. Sanitize data size before
reading corresponding message structures.

Fixes: 62b5412b1f4a ("usb: typec: ucsi: add PMIC Glink UCSI driver")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/usb/typec/ucsi/ucsi_glink.c | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

Comments

Konrad Dybcio April 16, 2024, 2:33 p.m. UTC | #1 
On 4/16/24 04:20, Dmitry Baryshkov wrote:
> The driver gets data from the DSP firmware. Sanitize data size before
> reading corresponding message structures.
> 
> Fixes: 62b5412b1f4a ("usb: typec: ucsi: add PMIC Glink UCSI driver")
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---

I think more backstory would be beneficial here.. Does this happen often?
What are the consequences? What are the causes? Can there be one-off invalid
messages, or does that mean the firwmare has entered some unstable state?

And I suppose, if answer to the last question is "unstable state", are we
doing something incorrectly in Linux that causes it to happen?

Konrad
diff mbox series

Patch

diff --git a/drivers/usb/typec/ucsi/ucsi_glink.c b/drivers/usb/typec/ucsi/ucsi_glink.c
index f7546bb488c3..6be9d89d4a28 100644
--- a/drivers/usb/typec/ucsi/ucsi_glink.c
+++ b/drivers/usb/typec/ucsi/ucsi_glink.c
@@ -223,9 +223,16 @@  static const struct ucsi_operations pmic_glink_ucsi_ops = {
 	.connector_status = pmic_glink_ucsi_connector_status,
 };
 
-static void pmic_glink_ucsi_read_ack(struct pmic_glink_ucsi *ucsi, const void *data, int len)
+static void pmic_glink_ucsi_read_ack(struct pmic_glink_ucsi *ucsi, const void *data, size_t len)
 {
-	const struct ucsi_read_buf_resp_msg *resp = data;
+	const struct ucsi_read_buf_resp_msg *resp;
+
+	if (len != sizeof (*resp)) {
+		dev_err_ratelimited(ucsi->dev, "Unexpected read response struct size %zd\n", len);
+		return;
+	}
+
+	resp = data;
 
 	if (resp->ret_code)
 		return;
@@ -234,9 +241,16 @@  static void pmic_glink_ucsi_read_ack(struct pmic_glink_ucsi *ucsi, const void *d
 	complete(&ucsi->read_ack);
 }
 
-static void pmic_glink_ucsi_write_ack(struct pmic_glink_ucsi *ucsi, const void *data, int len)
+static void pmic_glink_ucsi_write_ack(struct pmic_glink_ucsi *ucsi, const void *data, size_t len)
 {
-	const struct ucsi_write_buf_resp_msg *resp = data;
+	const struct ucsi_write_buf_resp_msg *resp;
+
+	if (len != sizeof (*resp)) {
+		dev_err_ratelimited(ucsi->dev, "Unexpected write ack struct size %zd\n", len);
+		return;
+	}
+
+	resp = data;
 
 	if (resp->ret_code)
 		return;