[PATCH] usb: typec: ucsi: Fix null pointer dereference in ucsi_sync_control_common

[PATCH] usb: typec: ucsi: Fix null pointer dereference in ucsi_sync_control_common

[Mario Limonciello (AMD)]

Add missing null check for cci parameter before dereferencing it in
ucsi_sync_control_common(). The function can be called with cci=NULL
from ucsi_acknowledge(), which leads to a null pointer dereference
when accessing *cci in the condition check.

The crash occurs because the code checks if cci is not null before
calling ucsi->ops->read_cci(ucsi, cci), but then immediately
dereferences cci without a null check in the following condition:
(*cci & UCSI_CCI_COMMAND_COMPLETE).

KASAN trace:
  KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
  RIP: 0010:ucsi_sync_control_common+0x2ae/0x4e0 [typec_ucsi]

Fixes: 667ecac55861 ("usb: typec: ucsi: return CCI and message from sync_control callback")
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
---
 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 9b3df776137a1..7129973f19e7e 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -97,7 +97,7 @@ int ucsi_sync_control_common(struct ucsi *ucsi, u64 command, u32 *cci)
 	if (!ret && cci)
 		ret = ucsi->ops->read_cci(ucsi, cci);
 
-	if (!ret && ucsi->message_in_size > 0 &&
+	if (!ret && cci && ucsi->message_in_size > 0 &&
 	    (*cci & UCSI_CCI_COMMAND_COMPLETE))
 		ret = ucsi->ops->read_message_in(ucsi, ucsi->message_in,
 						 ucsi->message_in_size);
-- 
2.43.0

Re: [PATCH] usb: typec: ucsi: Fix null pointer dereference in ucsi_sync_control_common

[Greg KH]

On Sun, Dec 14, 2025 at 12:36:41PM -0600, Mario Limonciello (AMD) wrote:
> Add missing null check for cci parameter before dereferencing it in
> ucsi_sync_control_common(). The function can be called with cci=NULL
> from ucsi_acknowledge(), which leads to a null pointer dereference
> when accessing *cci in the condition check.
> 
> The crash occurs because the code checks if cci is not null before
> calling ucsi->ops->read_cci(ucsi, cci), but then immediately
> dereferences cci without a null check in the following condition:
> (*cci & UCSI_CCI_COMMAND_COMPLETE).
> 
> KASAN trace:
>   KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
>   RIP: 0010:ucsi_sync_control_common+0x2ae/0x4e0 [typec_ucsi]
> 
> Fixes: 667ecac55861 ("usb: typec: ucsi: return CCI and message from sync_control callback")
> Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
> ---
>  drivers/usb/typec/ucsi/ucsi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- You have marked a patch with a "Fixes:" tag for a commit that is in an
  older released kernel, yet you do not have a cc: stable line in the
  signed-off-by area at all, which means that the patch will not be
  applied to any older kernel releases.  To properly fix this, please
  follow the documented rules in the
  Documentation/process/stable-kernel-rules.rst file for how to resolve
  this.

If you wish to discuss this problem further, or you have questions about
how to resolve this issue, please feel free to respond to this email and
Greg will reply once he has dug out from the pending patches received
from other developers.

thanks,

greg k-h's patch email bot

Re: [PATCH] usb: typec: ucsi: Fix null pointer dereference in ucsi_sync_control_common

[Heikki Krogerus]

Sun, Dec 14, 2025 at 12:36:41PM -0600, Mario Limonciello (AMD) kirjoitti:
> Add missing null check for cci parameter before dereferencing it in
> ucsi_sync_control_common(). The function can be called with cci=NULL
> from ucsi_acknowledge(), which leads to a null pointer dereference
> when accessing *cci in the condition check.
> 
> The crash occurs because the code checks if cci is not null before
> calling ucsi->ops->read_cci(ucsi, cci), but then immediately
> dereferences cci without a null check in the following condition:
> (*cci & UCSI_CCI_COMMAND_COMPLETE).
> 
> KASAN trace:
>   KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
>   RIP: 0010:ucsi_sync_control_common+0x2ae/0x4e0 [typec_ucsi]
> 
> Fixes: 667ecac55861 ("usb: typec: ucsi: return CCI and message from sync_control callback")
> Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>

I guess you need the CC stable tag.

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.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 9b3df776137a1..7129973f19e7e 100644
> --- a/drivers/usb/typec/ucsi/ucsi.c
> +++ b/drivers/usb/typec/ucsi/ucsi.c
> @@ -97,7 +97,7 @@ int ucsi_sync_control_common(struct ucsi *ucsi, u64 command, u32 *cci)
>  	if (!ret && cci)
>  		ret = ucsi->ops->read_cci(ucsi, cci);
>  
> -	if (!ret && ucsi->message_in_size > 0 &&
> +	if (!ret && cci && ucsi->message_in_size > 0 &&
>  	    (*cci & UCSI_CCI_COMMAND_COMPLETE))
>  		ret = ucsi->ops->read_message_in(ucsi, ucsi->message_in,
>  						 ucsi->message_in_size);
> -- 
> 2.43.0

-- 
heikki