That may silently corrupt the data. Instead, failing attempts
to read more than the interface can handle.
Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
---
drivers/usb/typec/ucsi/ucsi.c | 8 ++------
drivers/usb/typec/ucsi/ucsi.h | 2 ++
2 files changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index 4039851551c1..96ef099a6f84 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -99,12 +99,8 @@ static int ucsi_run_command(struct ucsi *ucsi, u64 command, u32 *cci,
*cci = 0;
- /*
- * Below UCSI 2.0, MESSAGE_IN was limited to 16 bytes. Truncate the
- * reads here.
- */
- if (ucsi->version <= UCSI_VERSION_1_2)
- size = clamp(size, 0, 16);
+ if (size > UCSI_MAX_DATA_LENGTH(ucsi))
+ return -EINVAL;
ret = ucsi->ops->sync_control(ucsi, command);
if (ret)
diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
index 7bc132b59027..5e3c6cb822c8 100644
--- a/drivers/usb/typec/ucsi/ucsi.h
+++ b/drivers/usb/typec/ucsi/ucsi.h
@@ -412,6 +412,8 @@ struct ucsi {
#define UCSI_DELAY_DEVICE_PDOS BIT(1) /* Reading PDOs fails until the parter is in PD mode */
};
+#define UCSI_MAX_DATA_LENGTH(u) (((u)->version < UCSI_VERSION_2_0) ? 0x10 : 0xff)
+
#define UCSI_MAX_SVID 5
#define UCSI_MAX_ALTMODES (UCSI_MAX_SVID * 6)
--
2.43.0
