[PATCH] fix: drivers/usb/typec/altmodes: dp_altmode_probe: missing typec_altmode_put_plug on error path

[PATCH] fix: drivers/usb/typec/altmodes: dp_altmode_probe: missing typec_altmode_put_plug on error path

[WenTao Liang]

In dp_altmode_probe(), typec_altmode_get_plug() acquires a reference on
plug. When the data role check fails (TYPEC_HOST check), the function
returns -EPROTO without calling typec_altmode_put_plug(plug), leaking the
plug reference. Other error paths (ENODEV, ENOMEM) correctly release the
reference.

Add typec_altmode_put_plug(plug) before returning on the EPROTO error
path to fix the leak.

Cc: stable@vger.kernel.org
Fixes: 41294342fad7 ("usb: typec: altmodes/displayport: do not enter mode if port is the UFP")
Signed-off-by: WenTao Liang <vulab@iscas.ac.cn>
---
 drivers/usb/typec/altmodes/displayport.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
index 263a89c5f324..06fe04e9e9b5 100644
--- a/drivers/usb/typec/altmodes/displayport.c
+++ b/drivers/usb/typec/altmodes/displayport.c
@@ -766,8 +766,10 @@ int dp_altmode_probe(struct typec_altmode *alt)
 	struct dp_altmode *dp;
 
 	/* Port can only be DFP_U. */
-	if (typec_altmode_get_data_role(alt) != TYPEC_HOST)
+	if (typec_altmode_get_data_role(alt) != TYPEC_HOST) {
+		typec_altmode_put_plug(plug);
 		return -EPROTO;
+	}
 
 	/* Make sure we have compatible pin configurations */
 	if (!(DP_CAP_PIN_ASSIGN_DFP_D(port->vdo) &
-- 
2.39.5 (Apple Git-154)

Re: [PATCH] fix: drivers/usb/typec/altmodes: dp_altmode_probe: missing typec_altmode_put_plug on error path

[Heikki Krogerus]

Hi,

I hate complain about trivial things, but the subject line has a bit
too much information. You have to improve it.

Please take a look at how the previous commits were written. My
suggestion is that you change it to, for example,
        "usb: typec: displayport: Fix a plug altmode leak"
or
        "usb: typec: displayport: Add missing typec_altmode_put_plug call"

Thanks,

On Sat, Jun 27, 2026 at 11:41:43AM +0800, WenTao Liang kirjoitti:
> In dp_altmode_probe(), typec_altmode_get_plug() acquires a reference on
> plug. When the data role check fails (TYPEC_HOST check), the function
> returns -EPROTO without calling typec_altmode_put_plug(plug), leaking the
> plug reference. Other error paths (ENODEV, ENOMEM) correctly release the
> reference.
> 
> Add typec_altmode_put_plug(plug) before returning on the EPROTO error
> path to fix the leak.
> 
> Cc: stable@vger.kernel.org
> Fixes: 41294342fad7 ("usb: typec: altmodes/displayport: do not enter mode if port is the UFP")
> Signed-off-by: WenTao Liang <vulab@iscas.ac.cn>

-- 
heikki