This is a note to let you know that I've just added the patch titled
usb: typec: ucsi: Don't truncate the reads
to the 6.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-typec-ucsi-don-t-truncate-the-reads.patch
and it can be found in the queue-6.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b56e61eb89890a31b0c41056fb5d3a6d9688454f
Author: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Date: Fri Aug 16 16:58:55 2024 +0300
usb: typec: ucsi: Don't truncate the reads
[ 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>
diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index 8cc43c866130a..8a81fec9efe36 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -103,12 +103,8 @@ 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 (ucsi->ops->read_cci(ucsi, cci))
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)
