[PATCH] usb: typec: ucsi: Fix off-by-one in connector validation

[PATCH] usb: typec: ucsi: Fix off-by-one in connector validation

[DongliLiu]

From: DongliLiu <dongli.liu@outlook.com>
Date: Mon, 30 Jun 2026 19:30:00 +0800
Subject: [PATCH] usb: typec: ucsi: Fix off-by-one in connector validation

UCSI_CCI_CONNECTOR() returns a 1-based connector index, while
num_connectors represents the total count of connectors. Using '<='
allows num_connectors itself as a valid index, which is off-by-one
since valid indices are 0 to num_connectors-1.

Change the comparison from '<=' to '<' to correctly reject the
out-of-bounds case.

Signed-off-by: DongliLiu <dongli.liu@outlook.com>
---
  drivers/usb/typec/ucsi/ucsi.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index xxxxxxx..yyyyyyy 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -xxx,yyy @@@ static void ucsi_notify_common(struct ucsi *ucsi, u32 cci)
      ...

-    if (UCSI_CCI_CONNECTOR(cci) <= ucsi->cap.num_connectors)
+    if (UCSI_CCI_CONNECTOR(cci) < ucsi->cap.num_connectors)
          ...
-- 
2.40.0

Re: [PATCH] usb: typec: ucsi: Fix off-by-one in connector validation

[Greg KH]

On Tue, Jun 30, 2026 at 07:30:31PM +0800, DongliLiu wrote:
> From: DongliLiu <dongli.liu@outlook.com>
> Date: Mon, 30 Jun 2026 19:30:00 +0800
> Subject: [PATCH] usb: typec: ucsi: Fix off-by-one in connector validation
> 
> UCSI_CCI_CONNECTOR() returns a 1-based connector index, while
> num_connectors represents the total count of connectors. Using '<='
> allows num_connectors itself as a valid index, which is off-by-one
> since valid indices are 0 to num_connectors-1.
> 
> Change the comparison from '<=' to '<' to correctly reject the
> out-of-bounds case.
> 
> Signed-off-by: DongliLiu <dongli.liu@outlook.com>
> ---
>  drivers/usb/typec/ucsi/ucsi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> index xxxxxxx..yyyyyyy 100644
> --- a/drivers/usb/typec/ucsi/ucsi.c
> +++ b/drivers/usb/typec/ucsi/ucsi.c
> @@ -xxx,yyy @@@ static void ucsi_notify_common(struct ucsi *ucsi, u32 cci)
>      ...
> 
> -    if (UCSI_CCI_CONNECTOR(cci) <= ucsi->cap.num_connectors)
> +    if (UCSI_CCI_CONNECTOR(cci) < ucsi->cap.num_connectors)
>          ...

Please actually create patches that can be applied and not use LLM tools
without documenting it properly.

thanks,

greg k-h