[PATCH] usb: typec: thunderbolt: Disable work before freeing tbt on remove

[PATCH] usb: typec: thunderbolt: Disable work before freeing tbt on remove

[Fan Wu]

tbt_altmode_remove() drops the plug and cable references without
draining tbt->work. The work function dereferences those references,
and can also requeue itself in its error path. The VDM callbacks can
queue the same work item.

Disable and drain tbt->work before dropping the references. This waits
for an existing invocation and prevents subsequent schedule_work()
calls from queueing it during teardown.

This issue was found by an in-house static analysis tool and confirmed
by manual code review.

Fixes: 100e25738659 ("usb: typec: Add driver for Thunderbolt 3 Alternate Mode")
Cc: stable@vger.kernel.org
Assisted-by: Codex:gpt-5.6
Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>
---
 drivers/usb/typec/altmodes/thunderbolt.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/typec/altmodes/thunderbolt.c b/drivers/usb/typec/altmodes/thunderbolt.c
index 32250b942..601d39ee1 100644
--- a/drivers/usb/typec/altmodes/thunderbolt.c
+++ b/drivers/usb/typec/altmodes/thunderbolt.c
@@ -303,6 +303,8 @@ static void tbt_altmode_remove(struct typec_altmode *alt)
 {
 	struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
 
+	disable_work_sync(&tbt->work);
+
 	for (int i = TYPEC_PLUG_SOP_PP; i >= 0; --i) {
 		if (tbt->plug[i])
 			typec_altmode_put_plug(tbt->plug[i]);
-- 
2.34.1

Re: [PATCH] usb: typec: thunderbolt: Disable work before freeing tbt on remove

[Heikki Krogerus]

On Sun, Aug 02, 2026 at 01:49:59AM +0000, Fan Wu wrote:
> tbt_altmode_remove() drops the plug and cable references without
> draining tbt->work. The work function dereferences those references,
> and can also requeue itself in its error path. The VDM callbacks can
> queue the same work item.
> 
> Disable and drain tbt->work before dropping the references. This waits
> for an existing invocation and prevents subsequent schedule_work()
> calls from queueing it during teardown.
> 
> This issue was found by an in-house static analysis tool and confirmed
> by manual code review.
> 
> Fixes: 100e25738659 ("usb: typec: Add driver for Thunderbolt 3 Alternate Mode")
> Cc: stable@vger.kernel.org
> Assisted-by: Codex:gpt-5.6
> Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>

Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
>  drivers/usb/typec/altmodes/thunderbolt.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/usb/typec/altmodes/thunderbolt.c b/drivers/usb/typec/altmodes/thunderbolt.c
> index 32250b942..601d39ee1 100644
> --- a/drivers/usb/typec/altmodes/thunderbolt.c
> +++ b/drivers/usb/typec/altmodes/thunderbolt.c
> @@ -303,6 +303,8 @@ static void tbt_altmode_remove(struct typec_altmode *alt)
>  {
>  	struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
>  
> +	disable_work_sync(&tbt->work);
> +
>  	for (int i = TYPEC_PLUG_SOP_PP; i >= 0; --i) {
>  		if (tbt->plug[i])
>  			typec_altmode_put_plug(tbt->plug[i]);
> -- 
> 2.34.1

-- 
heikki