From: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> [ Upstream commit 1d05c382ddb4e43ce251a50f308df5e42a2f6088 ] 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> Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20240816135859.3499351-3-heikki.krogerus@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 17155ed17fdf8..a8aeda77b1b6b 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 5a3481d36d7ab..db90b513f78a8 100644 --- a/drivers/usb/typec/ucsi/ucsi.h +++ b/drivers/usb/typec/ucsi/ucsi.h @@ -435,6 +435,8 @@ 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
