This is a note to let you know that I've just added the patch titled
usb: typec: ucsi: Clear PPM capability data in ucsi_init() error path
to the 4.19-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-clear-ppm-capability-data-in-ucsi_init-error-path.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f247f0a82a4f8c3bfed178d8fd9e069d1424ee4e Mon Sep 17 00:00:00 2001
From: Mayank Rana <mrana@xxxxxxxxxxxxxx>
Date: Wed, 9 Jun 2021 00:35:35 -0700
Subject: usb: typec: ucsi: Clear PPM capability data in ucsi_init() error path
From: Mayank Rana <mrana@xxxxxxxxxxxxxx>
commit f247f0a82a4f8c3bfed178d8fd9e069d1424ee4e upstream.
If ucsi_init() fails for some reason (e.g. ucsi_register_port()
fails or general communication failure to the PPM), particularly at
any point after the GET_CAPABILITY command had been issued, this
results in unwinding the initialization and returning an error.
However the ucsi structure's ucsi_capability member retains its
current value, including likely a non-zero num_connectors.
And because ucsi_init() itself is done in a workqueue a UCSI
interface driver will be unaware that it failed and may think the
ucsi_register() call was completely successful. Later, if
ucsi_unregister() is called, due to this stale ucsi->cap value it
would try to access the items in the ucsi->connector array which
might not be in a proper state or not even allocated at all and
results in NULL or invalid pointer dereference.
Fix this by clearing the ucsi->cap value to 0 during the error
path of ucsi_init() in order to prevent a later ucsi_unregister()
from entering the connector cleanup loop.
Fixes: c1b0bc2dabfa ("usb: typec: Add support for UCSI interface")
Cc: stable@xxxxxxxxxxxxxxx
Acked-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Signed-off-by: Mayank Rana <mrana@xxxxxxxxxxxxxx>
Signed-off-by: Jack Pham <jackp@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210609073535.5094-1-jackp@xxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/typec/ucsi/ucsi.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -735,6 +735,7 @@ err_unregister:
}
err_reset:
+ memset(&ucsi->cap, 0, sizeof(ucsi->cap));
ucsi_reset_ppm(ucsi);
err:
mutex_unlock(&ucsi->ppm_lock);
Patches currently in stable-queue which might be from mrana@xxxxxxxxxxxxxx are
queue-4.19/usb-typec-ucsi-clear-ppm-capability-data-in-ucsi_init-error-path.patch
