2024-05-14 22:02:47

by Amit Sunil Dhamne

Subject: [PATCH v1] usb: typec: tcpm: fix use-after-free case in tcpm_register_source_caps

There could be a potential use-after-free case in
tcpm_register_source_caps(). This could happen when:
* new (say invalid) source caps are advertised
* the existing source caps are unregistered
* tcpm_register_source_caps() returns with an error as
usb_power_delivery_register_capabilities() fails

This causes port->partner_source_caps to hold on to the now freed source
caps.

Reset port->partner_source_caps value to NULL after unregistering
existing source caps.

Fixes: 230ecdf71a64 ("usb: typec: tcpm: unregister existing source caps before re-registration")
Cc: [email protected]
Signed-off-by: Amit Sunil Dhamne <[email protected]>
---
drivers/usb/typec/tcpm/tcpm.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 8a1af08f71b6..be4127ef84e9 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -3014,8 +3014,10 @@ static int tcpm_register_source_caps(struct tcpm_port *port)
memcpy(caps.pdo, port->source_caps, sizeof(u32) * port->nr_source_caps);
caps.role = TYPEC_SOURCE;

- if (cap)
+ if (cap) {
usb_power_delivery_unregister_capabilities(cap);
+ port->partner_source_caps = NULL;
+ }

cap = usb_power_delivery_register_capabilities(port->partner_pd, &caps);
if (IS_ERR(cap))

base-commit: 51474ab44abf907023a8a875e799b07de461e466
--
2.45.0.rc1.225.g2a3ae87e7f-goog

2024-05-14 23:00:26

by Ondřej Jirman

Subject: Re: [PATCH v1] usb: typec: tcpm: fix use-after-free case in tcpm_register_source_caps

On Tue, May 14, 2024 at 03:01:31PM GMT, Amit Sunil Dhamne wrote:
> There could be a potential use-after-free case in
> tcpm_register_source_caps(). This could happen when:
> * new (say invalid) source caps are advertised
> * the existing source caps are unregistered
> * tcpm_register_source_caps() returns with an error as
> usb_power_delivery_register_capabilities() fails
>
> This causes port->partner_source_caps to hold on to the now freed source
> caps.
>
> Reset port->partner_source_caps value to NULL after unregistering
> existing source caps.
>
> Fixes: 230ecdf71a64 ("usb: typec: tcpm: unregister existing source caps before re-registration")
> Cc: [email protected]
> Signed-off-by: Amit Sunil Dhamne <[email protected]>
>

Reviewed-by: Ondrej Jirman <[email protected]>

Thanks for the fix.

Kind regards,
o.

>
> ---
> drivers/usb/typec/tcpm/tcpm.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index 8a1af08f71b6..be4127ef84e9 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -3014,8 +3014,10 @@ static int tcpm_register_source_caps(struct tcpm_port *port)
> memcpy(caps.pdo, port->source_caps, sizeof(u32) * port->nr_source_caps);
> caps.role = TYPEC_SOURCE;
>
> - if (cap)
> + if (cap) {
> usb_power_delivery_unregister_capabilities(cap);
> + port->partner_source_caps = NULL;
> + }
>
> cap = usb_power_delivery_register_capabilities(port->partner_pd, &caps);
> if (IS_ERR(cap))
>
> base-commit: 51474ab44abf907023a8a875e799b07de461e466
> --
> 2.45.0.rc1.225.g2a3ae87e7f-goog
>

2024-05-19 08:00:14

by Dmitry Baryshkov

Subject: Re: [PATCH v1] usb: typec: tcpm: fix use-after-free case in tcpm_register_source_caps

On Tue, May 14, 2024 at 03:01:31PM -0700, Amit Sunil Dhamne wrote:
> There could be a potential use-after-free case in
> tcpm_register_source_caps(). This could happen when:
> * new (say invalid) source caps are advertised
> * the existing source caps are unregistered
> * tcpm_register_source_caps() returns with an error as
> usb_power_delivery_register_capabilities() fails
>
> This causes port->partner_source_caps to hold on to the now freed source
> caps.
>
> Reset port->partner_source_caps value to NULL after unregistering
> existing source caps.
>
> Fixes: 230ecdf71a64 ("usb: typec: tcpm: unregister existing source caps before re-registration")
> Cc: [email protected]
> Signed-off-by: Amit Sunil Dhamne <[email protected]>
> ---
> drivers/usb/typec/tcpm/tcpm.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>

Reviewed-by: Dmitry Baryshkov <[email protected]>


--
With best wishes
Dmitry

2024-05-21 18:56:53

by Heikki Krogerus

Subject: Re: [PATCH v1] usb: typec: tcpm: fix use-after-free case in tcpm_register_source_caps

On Tue, May 14, 2024 at 03:01:31PM -0700, Amit Sunil Dhamne wrote:
> There could be a potential use-after-free case in
> tcpm_register_source_caps(). This could happen when:
> * new (say invalid) source caps are advertised
> * the existing source caps are unregistered
> * tcpm_register_source_caps() returns with an error as
> usb_power_delivery_register_capabilities() fails
>
> This causes port->partner_source_caps to hold on to the now freed source
> caps.
>
> Reset port->partner_source_caps value to NULL after unregistering
> existing source caps.
>
> Fixes: 230ecdf71a64 ("usb: typec: tcpm: unregister existing source caps before re-registration")
> Cc: [email protected]
> Signed-off-by: Amit Sunil Dhamne <[email protected]>

Reviewed-by: Heikki Krogerus <[email protected]>

> ---
> drivers/usb/typec/tcpm/tcpm.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index 8a1af08f71b6..be4127ef84e9 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -3014,8 +3014,10 @@ static int tcpm_register_source_caps(struct tcpm_port *port)
> memcpy(caps.pdo, port->source_caps, sizeof(u32) * port->nr_source_caps);
> caps.role = TYPEC_SOURCE;
>
> - if (cap)
> + if (cap) {
> usb_power_delivery_unregister_capabilities(cap);
> + port->partner_source_caps = NULL;
> + }
>
> cap = usb_power_delivery_register_capabilities(port->partner_pd, &caps);
> if (IS_ERR(cap))
>
> base-commit: 51474ab44abf907023a8a875e799b07de461e466
> --
> 2.45.0.rc1.225.g2a3ae87e7f-goog

--
heikki