* [PATCH v2] usb: typec: ucsi: Fix NULL pointer dereference in ucsi_displayport_vdm()
@ 2024-07-23 14:13 Ma Ke
2024-07-23 14:21 ` Dmitry Baryshkov
2024-07-23 17:33 ` Greg KH
0 siblings, 2 replies; 3+ messages in thread
From: Ma Ke @ 2024-07-23 14:13 UTC (permalink / raw)
To: heikki.krogerus, gregkh, utkarsh.h.patel, abhishekpandit,
andriy.shevchenko, make24, kyletso
Cc: linux-usb, linux-kernel, stable
When dp->con->partner is an error, a NULL pointer dereference may occur.
Add a check for dp->con->partner to avoid dereferencing a NULL pointer.
Cc: stable@vger.kernel.org
Fixes: 372adf075a43 ("usb: typec: ucsi: Determine common SVDM Version")
Signed-off-by: Ma Ke <make24@iscas.ac.cn>
---
Changes in v2:
- added Cc stable line;
- fixed a typo.
---
drivers/usb/typec/ucsi/displayport.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/usb/typec/ucsi/displayport.c b/drivers/usb/typec/ucsi/displayport.c
index 420af5139c70..ecc706e0800d 100644
--- a/drivers/usb/typec/ucsi/displayport.c
+++ b/drivers/usb/typec/ucsi/displayport.c
@@ -222,6 +222,8 @@ static int ucsi_displayport_vdm(struct typec_altmode *alt,
switch (cmd_type) {
case CMDT_INIT:
if (PD_VDO_SVDM_VER(header) < svdm_version) {
+ if (IS_ERR_OR_NULL(dp->con->partner))
+ break;
typec_partner_set_svdm_version(dp->con->partner, PD_VDO_SVDM_VER(header));
svdm_version = PD_VDO_SVDM_VER(header);
}
--
2.25.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH v2] usb: typec: ucsi: Fix NULL pointer dereference in ucsi_displayport_vdm()
2024-07-23 14:13 [PATCH v2] usb: typec: ucsi: Fix NULL pointer dereference in ucsi_displayport_vdm() Ma Ke
@ 2024-07-23 14:21 ` Dmitry Baryshkov
2024-07-23 17:33 ` Greg KH
1 sibling, 0 replies; 3+ messages in thread
From: Dmitry Baryshkov @ 2024-07-23 14:21 UTC (permalink / raw)
To: Ma Ke
Cc: heikki.krogerus, gregkh, utkarsh.h.patel, abhishekpandit,
andriy.shevchenko, kyletso, linux-usb, linux-kernel, stable
On Tue, Jul 23, 2024 at 10:13:44PM GMT, Ma Ke wrote:
> When dp->con->partner is an error, a NULL pointer dereference may occur.
> Add a check for dp->con->partner to avoid dereferencing a NULL pointer.
>
> Cc: stable@vger.kernel.org
> Fixes: 372adf075a43 ("usb: typec: ucsi: Determine common SVDM Version")
> Signed-off-by: Ma Ke <make24@iscas.ac.cn>
> ---
> Changes in v2:
> - added Cc stable line;
> - fixed a typo.
> ---
> drivers/usb/typec/ucsi/displayport.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/usb/typec/ucsi/displayport.c b/drivers/usb/typec/ucsi/displayport.c
> index 420af5139c70..ecc706e0800d 100644
> --- a/drivers/usb/typec/ucsi/displayport.c
> +++ b/drivers/usb/typec/ucsi/displayport.c
> @@ -222,6 +222,8 @@ static int ucsi_displayport_vdm(struct typec_altmode *alt,
> switch (cmd_type) {
> case CMDT_INIT:
> if (PD_VDO_SVDM_VER(header) < svdm_version) {
> + if (IS_ERR_OR_NULL(dp->con->partner))
Usually IS_ERR_OR_NULL is one of the red flags. It is either IS_ERR or
NULL, but not both.
Also could you please describe the path how we can end up here without a
proper dp->con->partner.
> + break;
> typec_partner_set_svdm_version(dp->con->partner, PD_VDO_SVDM_VER(header));
> svdm_version = PD_VDO_SVDM_VER(header);
> }
> --
> 2.25.1
>
--
With best wishes
Dmitry
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH v2] usb: typec: ucsi: Fix NULL pointer dereference in ucsi_displayport_vdm()
2024-07-23 14:13 [PATCH v2] usb: typec: ucsi: Fix NULL pointer dereference in ucsi_displayport_vdm() Ma Ke
2024-07-23 14:21 ` Dmitry Baryshkov
@ 2024-07-23 17:33 ` Greg KH
1 sibling, 0 replies; 3+ messages in thread
From: Greg KH @ 2024-07-23 17:33 UTC (permalink / raw)
To: Ma Ke
Cc: heikki.krogerus, utkarsh.h.patel, abhishekpandit,
andriy.shevchenko, kyletso, linux-usb, linux-kernel, stable
On Tue, Jul 23, 2024 at 10:13:44PM +0800, Ma Ke wrote:
> When dp->con->partner is an error, a NULL pointer dereference may occur.
> Add a check for dp->con->partner to avoid dereferencing a NULL pointer.
>
> Cc: stable@vger.kernel.org
> Fixes: 372adf075a43 ("usb: typec: ucsi: Determine common SVDM Version")
> Signed-off-by: Ma Ke <make24@iscas.ac.cn>
How was this found? How was it tested? Given that the first version
didn't even build, it seems like this was never tested at all...
thanks,
greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
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2024-07-23 14:13 [PATCH v2] usb: typec: ucsi: Fix NULL pointer dereference in ucsi_displayport_vdm() Ma Ke
2024-07-23 14:21 ` Dmitry Baryshkov
2024-07-23 17:33 ` Greg KH
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