From: Heikki Krogerus Date: Fri, 16 Aug 2024 13:58:55 +0000 (+0300) Subject: usb: typec: ucsi: Don't truncate the reads X-Git-Tag: v6.12-rc1~42^2~84 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1d05c382ddb4e43ce251a50f308df5e42a2f6088;p=thirdparty%2Fkernel%2Flinux.git usb: typec: ucsi: Don't truncate the reads That may silently corrupt the data. Instead, failing attempts to read more than the interface can handle. Signed-off-by: Heikki Krogerus Reviewed-by: Abhishek Pandit-Subedi Link: https://lore.kernel.org/r/20240816135859.3499351-3-heikki.krogerus@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c index 546352b53bc42..250bd20f2cd9a 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 6359baa22858e..e8ece3fdcbf2c 100644 --- a/drivers/usb/typec/ucsi/ucsi.h +++ b/drivers/usb/typec/ucsi/ucsi.h @@ -415,6 +415,8 @@ 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)