From: Jack Pham <jackp@codeaurora.org>
To: Heikki Krogerus <heikki.krogerus@linux.intel.com>,
Greg KH <gregkh@linuxfoundation.org>
Cc: Subbaraman Narayanamurthy <subbaram@codeaurora.org>,
linux-usb@vger.kernel.org, Mayank Rana <mrana@codeaurora.org>,
stable@vger.kernel.org, Jack Pham <jackp@codeaurora.org>
Subject: [PATCH] usb: typec: ucsi: Clear PPM capability data in ucsi_init() error path
Date: Wed, 9 Jun 2021 00:35:35 -0700 [thread overview]
Message-ID: <20210609073535.5094-1-jackp@codeaurora.org> (raw)
From: Mayank Rana <mrana@codeaurora.org>
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@vger.kernel.org
Signed-off-by: Mayank Rana <mrana@codeaurora.org>
Signed-off-by: Jack Pham <jackp@codeaurora.org>
---
drivers/usb/typec/ucsi/ucsi.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index b433169ef6fa..b7d104c80d85 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -1253,6 +1253,7 @@ static int ucsi_init(struct ucsi *ucsi)
}
err_reset:
+ memset(&ucsi->cap, 0, sizeof(ucsi->cap));
ucsi_reset_ppm(ucsi);
err:
return ret;
--
2.24.0
next reply other threads:[~2021-06-09 7:35 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-09 7:35 Jack Pham [this message]
2021-06-09 12:03 ` [PATCH] usb: typec: ucsi: Clear PPM capability data in ucsi_init() error path Heikki Krogerus
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