* [PATCH] drm/dp_mst: Avoid NULL pointer dereference
@ 2019-12-26 2:31 ` Wayne Lin
0 siblings, 0 replies; 12+ messages in thread
From: Wayne Lin @ 2019-12-26 2:31 UTC (permalink / raw)
To: dri-devel, amd-gfx
Cc: lyude, Nicholas.Kazlauskas, harry.wentland, mikita.lipski,
jerry.zuo, stable, Wayne Lin
[Why]
Found kernel NULL pointer dereference under the below situation:
src — HDMI_Monitor src — HDMI_Monitor
e.g.: \ =>
MSTB — MSTB (unplug) MSTB — MSTB
When display 1 HDMI and 2 DP daisy chain monitors, unplugging the dp
cable connected to source causes kernel NULL pointer dereference at
drm_dp_mst_atomic_check_bw_limit(). When calculating pbn_limit, if
branch is null, accessing "&branch->ports" causes the problem.
[How]
Judge branch is null or not at the beginning. If it is null, return 0.
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Cc: stable@vger.kernel.org
---
drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 7d2d31eaf003..a6473e3ab448 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -4707,6 +4707,9 @@ int drm_dp_mst_atomic_check_bw_limit(struct drm_dp_mst_branch *branch,
struct drm_dp_vcpi_allocation *vcpi;
int pbn_limit = 0, pbn_used = 0;
+ if (!branch)
+ return 0;
+
list_for_each_entry(port, &branch->ports, next) {
if (port->mstb)
if (drm_dp_mst_atomic_check_bw_limit(port->mstb, mst_state))
--
2.17.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH] drm/dp_mst: Avoid NULL pointer dereference
@ 2019-12-26 2:31 ` Wayne Lin
0 siblings, 0 replies; 12+ messages in thread
From: Wayne Lin @ 2019-12-26 2:31 UTC (permalink / raw)
To: dri-devel, amd-gfx
Cc: stable, jerry.zuo, Wayne Lin, mikita.lipski, Nicholas.Kazlauskas
[Why]
Found kernel NULL pointer dereference under the below situation:
src — HDMI_Monitor src — HDMI_Monitor
e.g.: \ =>
MSTB — MSTB (unplug) MSTB — MSTB
When display 1 HDMI and 2 DP daisy chain monitors, unplugging the dp
cable connected to source causes kernel NULL pointer dereference at
drm_dp_mst_atomic_check_bw_limit(). When calculating pbn_limit, if
branch is null, accessing "&branch->ports" causes the problem.
[How]
Judge branch is null or not at the beginning. If it is null, return 0.
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Cc: stable@vger.kernel.org
---
drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 7d2d31eaf003..a6473e3ab448 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -4707,6 +4707,9 @@ int drm_dp_mst_atomic_check_bw_limit(struct drm_dp_mst_branch *branch,
struct drm_dp_vcpi_allocation *vcpi;
int pbn_limit = 0, pbn_used = 0;
+ if (!branch)
+ return 0;
+
list_for_each_entry(port, &branch->ports, next) {
if (port->mstb)
if (drm_dp_mst_atomic_check_bw_limit(port->mstb, mst_state))
--
2.17.1
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH] drm/dp_mst: Avoid NULL pointer dereference
@ 2019-12-26 2:31 ` Wayne Lin
0 siblings, 0 replies; 12+ messages in thread
From: Wayne Lin @ 2019-12-26 2:31 UTC (permalink / raw)
To: dri-devel, amd-gfx
Cc: stable, jerry.zuo, Wayne Lin, mikita.lipski, harry.wentland,
Nicholas.Kazlauskas
[Why]
Found kernel NULL pointer dereference under the below situation:
src — HDMI_Monitor src — HDMI_Monitor
e.g.: \ =>
MSTB — MSTB (unplug) MSTB — MSTB
When display 1 HDMI and 2 DP daisy chain monitors, unplugging the dp
cable connected to source causes kernel NULL pointer dereference at
drm_dp_mst_atomic_check_bw_limit(). When calculating pbn_limit, if
branch is null, accessing "&branch->ports" causes the problem.
[How]
Judge branch is null or not at the beginning. If it is null, return 0.
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Cc: stable@vger.kernel.org
---
drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 7d2d31eaf003..a6473e3ab448 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -4707,6 +4707,9 @@ int drm_dp_mst_atomic_check_bw_limit(struct drm_dp_mst_branch *branch,
struct drm_dp_vcpi_allocation *vcpi;
int pbn_limit = 0, pbn_used = 0;
+ if (!branch)
+ return 0;
+
list_for_each_entry(port, &branch->ports, next) {
if (port->mstb)
if (drm_dp_mst_atomic_check_bw_limit(port->mstb, mst_state))
--
2.17.1
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH] drm/dp_mst: Avoid NULL pointer dereference
2019-12-26 2:31 ` Wayne Lin
(?)
@ 2019-12-26 15:04 ` Lipski, Mikita
-1 siblings, 0 replies; 12+ messages in thread
From: Lipski, Mikita @ 2019-12-26 15:04 UTC (permalink / raw)
To: Lin, Wayne, dri-devel, amd-gfx
Cc: lyude, Kazlauskas, Nicholas, Wentland, Harry, Zuo, Jerry, stable
[AMD Official Use Only - Internal Distribution Only]
Thanks for the catch,
Reviewed-by: Mikita Lipski <Mikita.Lipski@amd.com>
From: Wayne Lin <Wayne.Lin@amd.com>
Sent: Wednesday, December 25, 2019 9:31 PM
To: dri-devel@lists.freedesktop.org <dri-devel@lists.freedesktop.org>; amd-gfx@lists.freedesktop.org <amd-gfx@lists.freedesktop.org>
Cc: lyude@redhat.com <lyude@redhat.com>; Kazlauskas, Nicholas <Nicholas.Kazlauskas@amd.com>; Wentland, Harry <Harry.Wentland@amd.com>; Lipski, Mikita <Mikita.Lipski@amd.com>; Zuo, Jerry <Jerry.Zuo@amd.com>; stable@vger.kernel.org <stable@vger.kernel.org>;
Lin, Wayne <Wayne.Lin@amd.com>
Subject: [PATCH] drm/dp_mst: Avoid NULL pointer dereference
[Why]
Found kernel NULL pointer dereference under the below situation:
src — HDMI_Monitor src — HDMI_Monitor
e.g.: \ =>
MSTB — MSTB (unplug) MSTB — MSTB
When display 1 HDMI and 2 DP daisy chain monitors, unplugging the dp
cable connected to source causes kernel NULL pointer dereference at
drm_dp_mst_atomic_check_bw_limit(). When calculating pbn_limit, if
branch is null, accessing "&branch->ports" causes the problem.
[How]
Judge branch is null or not at the beginning. If it is null, return 0.
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Cc: stable@vger.kernel.org
---
drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 7d2d31eaf003..a6473e3ab448 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -4707,6 +4707,9 @@ int drm_dp_mst_atomic_check_bw_limit(struct drm_dp_mst_branch *branch,
struct drm_dp_vcpi_allocation *vcpi;
int pbn_limit = 0, pbn_used = 0;
+ if (!branch)
+ return 0;
+
list_for_each_entry(port, &branch->ports, next) {
if (port->mstb)
if (drm_dp_mst_atomic_check_bw_limit(port->mstb, mst_state))
--
2.17.1
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] drm/dp_mst: Avoid NULL pointer dereference
@ 2019-12-26 15:04 ` Lipski, Mikita
0 siblings, 0 replies; 12+ messages in thread
From: Lipski, Mikita @ 2019-12-26 15:04 UTC (permalink / raw)
To: Lin, Wayne, dri-devel, amd-gfx; +Cc: Zuo, Jerry, Kazlauskas, Nicholas, stable
[AMD Official Use Only - Internal Distribution Only]
Thanks for the catch,
Reviewed-by: Mikita Lipski <Mikita.Lipski@amd.com>
From: Wayne Lin <Wayne.Lin@amd.com>
Sent: Wednesday, December 25, 2019 9:31 PM
To: dri-devel@lists.freedesktop.org <dri-devel@lists.freedesktop.org>; amd-gfx@lists.freedesktop.org <amd-gfx@lists.freedesktop.org>
Cc: lyude@redhat.com <lyude@redhat.com>; Kazlauskas, Nicholas <Nicholas.Kazlauskas@amd.com>; Wentland, Harry <Harry.Wentland@amd.com>; Lipski, Mikita <Mikita.Lipski@amd.com>; Zuo, Jerry <Jerry.Zuo@amd.com>; stable@vger.kernel.org <stable@vger.kernel.org>;
Lin, Wayne <Wayne.Lin@amd.com>
Subject: [PATCH] drm/dp_mst: Avoid NULL pointer dereference
[Why]
Found kernel NULL pointer dereference under the below situation:
src — HDMI_Monitor src — HDMI_Monitor
e.g.: \ =>
MSTB — MSTB (unplug) MSTB — MSTB
When display 1 HDMI and 2 DP daisy chain monitors, unplugging the dp
cable connected to source causes kernel NULL pointer dereference at
drm_dp_mst_atomic_check_bw_limit(). When calculating pbn_limit, if
branch is null, accessing "&branch->ports" causes the problem.
[How]
Judge branch is null or not at the beginning. If it is null, return 0.
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Cc: stable@vger.kernel.org
---
drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 7d2d31eaf003..a6473e3ab448 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -4707,6 +4707,9 @@ int drm_dp_mst_atomic_check_bw_limit(struct drm_dp_mst_branch *branch,
struct drm_dp_vcpi_allocation *vcpi;
int pbn_limit = 0, pbn_used = 0;
+ if (!branch)
+ return 0;
+
list_for_each_entry(port, &branch->ports, next) {
if (port->mstb)
if (drm_dp_mst_atomic_check_bw_limit(port->mstb, mst_state))
--
2.17.1
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] drm/dp_mst: Avoid NULL pointer dereference
@ 2019-12-26 15:04 ` Lipski, Mikita
0 siblings, 0 replies; 12+ messages in thread
From: Lipski, Mikita @ 2019-12-26 15:04 UTC (permalink / raw)
To: Lin, Wayne, dri-devel, amd-gfx
Cc: Wentland, Harry, Zuo, Jerry, Kazlauskas, Nicholas, stable
[AMD Official Use Only - Internal Distribution Only]
Thanks for the catch,
Reviewed-by: Mikita Lipski <Mikita.Lipski@amd.com>
From: Wayne Lin <Wayne.Lin@amd.com>
Sent: Wednesday, December 25, 2019 9:31 PM
To: dri-devel@lists.freedesktop.org <dri-devel@lists.freedesktop.org>; amd-gfx@lists.freedesktop.org <amd-gfx@lists.freedesktop.org>
Cc: lyude@redhat.com <lyude@redhat.com>; Kazlauskas, Nicholas <Nicholas.Kazlauskas@amd.com>; Wentland, Harry <Harry.Wentland@amd.com>; Lipski, Mikita <Mikita.Lipski@amd.com>; Zuo, Jerry <Jerry.Zuo@amd.com>; stable@vger.kernel.org <stable@vger.kernel.org>;
Lin, Wayne <Wayne.Lin@amd.com>
Subject: [PATCH] drm/dp_mst: Avoid NULL pointer dereference
[Why]
Found kernel NULL pointer dereference under the below situation:
src — HDMI_Monitor src — HDMI_Monitor
e.g.: \ =>
MSTB — MSTB (unplug) MSTB — MSTB
When display 1 HDMI and 2 DP daisy chain monitors, unplugging the dp
cable connected to source causes kernel NULL pointer dereference at
drm_dp_mst_atomic_check_bw_limit(). When calculating pbn_limit, if
branch is null, accessing "&branch->ports" causes the problem.
[How]
Judge branch is null or not at the beginning. If it is null, return 0.
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Cc: stable@vger.kernel.org
---
drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 7d2d31eaf003..a6473e3ab448 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -4707,6 +4707,9 @@ int drm_dp_mst_atomic_check_bw_limit(struct drm_dp_mst_branch *branch,
struct drm_dp_vcpi_allocation *vcpi;
int pbn_limit = 0, pbn_used = 0;
+ if (!branch)
+ return 0;
+
list_for_each_entry(port, &branch->ports, next) {
if (port->mstb)
if (drm_dp_mst_atomic_check_bw_limit(port->mstb, mst_state))
--
2.17.1
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] drm/dp_mst: Avoid NULL pointer dereference
2019-12-26 2:31 ` Wayne Lin
(?)
@ 2020-01-03 20:35 ` Lyude Paul
-1 siblings, 0 replies; 12+ messages in thread
From: Lyude Paul @ 2020-01-03 20:35 UTC (permalink / raw)
To: Wayne Lin, dri-devel, amd-gfx
Cc: Nicholas.Kazlauskas, harry.wentland, mikita.lipski, jerry.zuo, stable
Back from the holidays!
Reviewed-by: Lyude Paul <lyude@redhat.com>
Do you need me to push this to drm-misc?
On Thu, 2019-12-26 at 10:31 +0800, Wayne Lin wrote:
> [Why]
> Found kernel NULL pointer dereference under the below situation:
>
> src — HDMI_Monitor src — HDMI_Monitor
> e.g.: \ =>
> MSTB — MSTB (unplug) MSTB — MSTB
>
> When display 1 HDMI and 2 DP daisy chain monitors, unplugging the dp
> cable connected to source causes kernel NULL pointer dereference at
> drm_dp_mst_atomic_check_bw_limit(). When calculating pbn_limit, if
> branch is null, accessing "&branch->ports" causes the problem.
>
> [How]
> Judge branch is null or not at the beginning. If it is null, return 0.
>
> Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
> Cc: stable@vger.kernel.org
> ---
> drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c
> b/drivers/gpu/drm/drm_dp_mst_topology.c
> index 7d2d31eaf003..a6473e3ab448 100644
> --- a/drivers/gpu/drm/drm_dp_mst_topology.c
> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
> @@ -4707,6 +4707,9 @@ int drm_dp_mst_atomic_check_bw_limit(struct
> drm_dp_mst_branch *branch,
> struct drm_dp_vcpi_allocation *vcpi;
> int pbn_limit = 0, pbn_used = 0;
>
> + if (!branch)
> + return 0;
> +
> list_for_each_entry(port, &branch->ports, next) {
> if (port->mstb)
> if (drm_dp_mst_atomic_check_bw_limit(port->mstb,
> mst_state))
--
Cheers,
Lyude Paul
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] drm/dp_mst: Avoid NULL pointer dereference
@ 2020-01-03 20:35 ` Lyude Paul
0 siblings, 0 replies; 12+ messages in thread
From: Lyude Paul @ 2020-01-03 20:35 UTC (permalink / raw)
To: Wayne Lin, dri-devel, amd-gfx
Cc: jerry.zuo, mikita.lipski, Nicholas.Kazlauskas, stable
Back from the holidays!
Reviewed-by: Lyude Paul <lyude@redhat.com>
Do you need me to push this to drm-misc?
On Thu, 2019-12-26 at 10:31 +0800, Wayne Lin wrote:
> [Why]
> Found kernel NULL pointer dereference under the below situation:
>
> src — HDMI_Monitor src — HDMI_Monitor
> e.g.: \ =>
> MSTB — MSTB (unplug) MSTB — MSTB
>
> When display 1 HDMI and 2 DP daisy chain monitors, unplugging the dp
> cable connected to source causes kernel NULL pointer dereference at
> drm_dp_mst_atomic_check_bw_limit(). When calculating pbn_limit, if
> branch is null, accessing "&branch->ports" causes the problem.
>
> [How]
> Judge branch is null or not at the beginning. If it is null, return 0.
>
> Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
> Cc: stable@vger.kernel.org
> ---
> drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c
> b/drivers/gpu/drm/drm_dp_mst_topology.c
> index 7d2d31eaf003..a6473e3ab448 100644
> --- a/drivers/gpu/drm/drm_dp_mst_topology.c
> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
> @@ -4707,6 +4707,9 @@ int drm_dp_mst_atomic_check_bw_limit(struct
> drm_dp_mst_branch *branch,
> struct drm_dp_vcpi_allocation *vcpi;
> int pbn_limit = 0, pbn_used = 0;
>
> + if (!branch)
> + return 0;
> +
> list_for_each_entry(port, &branch->ports, next) {
> if (port->mstb)
> if (drm_dp_mst_atomic_check_bw_limit(port->mstb,
> mst_state))
--
Cheers,
Lyude Paul
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] drm/dp_mst: Avoid NULL pointer dereference
@ 2020-01-03 20:35 ` Lyude Paul
0 siblings, 0 replies; 12+ messages in thread
From: Lyude Paul @ 2020-01-03 20:35 UTC (permalink / raw)
To: Wayne Lin, dri-devel, amd-gfx
Cc: jerry.zuo, mikita.lipski, harry.wentland, Nicholas.Kazlauskas, stable
Back from the holidays!
Reviewed-by: Lyude Paul <lyude@redhat.com>
Do you need me to push this to drm-misc?
On Thu, 2019-12-26 at 10:31 +0800, Wayne Lin wrote:
> [Why]
> Found kernel NULL pointer dereference under the below situation:
>
> src — HDMI_Monitor src — HDMI_Monitor
> e.g.: \ =>
> MSTB — MSTB (unplug) MSTB — MSTB
>
> When display 1 HDMI and 2 DP daisy chain monitors, unplugging the dp
> cable connected to source causes kernel NULL pointer dereference at
> drm_dp_mst_atomic_check_bw_limit(). When calculating pbn_limit, if
> branch is null, accessing "&branch->ports" causes the problem.
>
> [How]
> Judge branch is null or not at the beginning. If it is null, return 0.
>
> Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
> Cc: stable@vger.kernel.org
> ---
> drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c
> b/drivers/gpu/drm/drm_dp_mst_topology.c
> index 7d2d31eaf003..a6473e3ab448 100644
> --- a/drivers/gpu/drm/drm_dp_mst_topology.c
> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
> @@ -4707,6 +4707,9 @@ int drm_dp_mst_atomic_check_bw_limit(struct
> drm_dp_mst_branch *branch,
> struct drm_dp_vcpi_allocation *vcpi;
> int pbn_limit = 0, pbn_used = 0;
>
> + if (!branch)
> + return 0;
> +
> list_for_each_entry(port, &branch->ports, next) {
> if (port->mstb)
> if (drm_dp_mst_atomic_check_bw_limit(port->mstb,
> mst_state))
--
Cheers,
Lyude Paul
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
^ permalink raw reply [flat|nested] 12+ messages in thread
* 回覆: [PATCH] drm/dp_mst: Avoid NULL pointer dereference
2020-01-03 20:35 ` Lyude Paul
(?)
@ 2020-01-06 7:34 ` Lin, Wayne
-1 siblings, 0 replies; 12+ messages in thread
From: Lin, Wayne @ 2020-01-06 7:34 UTC (permalink / raw)
To: Lyude Paul, dri-devel, amd-gfx
Cc: Kazlauskas, Nicholas, Wentland, Harry, Lipski, Mikita, Zuo,
Jerry, stable
[AMD Public Use]
> -----原始郵件-----
> 寄件者: Lyude Paul <lyude@redhat.com>
> 寄件日期: Saturday, January 4, 2020 4:35 AM
> 收件者: Lin, Wayne <Wayne.Lin@amd.com>; dri-
> devel@lists.freedesktop.org; amd-gfx@lists.freedesktop.org
> 副本: Kazlauskas, Nicholas <Nicholas.Kazlauskas@amd.com>; Wentland,
> Harry <Harry.Wentland@amd.com>; Lipski, Mikita <Mikita.Lipski@amd.com>;
> Zuo, Jerry <Jerry.Zuo@amd.com>; stable@vger.kernel.org
> 主旨: Re: [PATCH] drm/dp_mst: Avoid NULL pointer dereference
>
> Back from the holidays!
>
> Reviewed-by: Lyude Paul <lyude@redhat.com>
>
> Do you need me to push this to drm-misc?
>
Thanks for your time!
And yes, please help to push this to drm-misc.
> On Thu, 2019-12-26 at 10:31 +0800, Wayne Lin wrote:
> > [Why]
> > Found kernel NULL pointer dereference under the below situation:
> >
> > src — HDMI_Monitor src — HDMI_Monitor
> > e.g.: \ =>
> > MSTB — MSTB (unplug) MSTB — MSTB
> >
> > When display 1 HDMI and 2 DP daisy chain monitors, unplugging the dp
> > cable connected to source causes kernel NULL pointer dereference at
> > drm_dp_mst_atomic_check_bw_limit(). When calculating pbn_limit, if
> > branch is null, accessing "&branch->ports" causes the problem.
> >
> > [How]
> > Judge branch is null or not at the beginning. If it is null, return 0.
> >
> > Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
> > Cc: stable@vger.kernel.org
> > ---
> > drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c
> > b/drivers/gpu/drm/drm_dp_mst_topology.c
> > index 7d2d31eaf003..a6473e3ab448 100644
> > --- a/drivers/gpu/drm/drm_dp_mst_topology.c
> > +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
> > @@ -4707,6 +4707,9 @@ int drm_dp_mst_atomic_check_bw_limit(struct
> > drm_dp_mst_branch *branch,
> > struct drm_dp_vcpi_allocation *vcpi;
> > int pbn_limit = 0, pbn_used = 0;
> >
> > + if (!branch)
> > + return 0;
> > +
> > list_for_each_entry(port, &branch->ports, next) {
> > if (port->mstb)
> > if (drm_dp_mst_atomic_check_bw_limit(port->mstb,
> > mst_state))
> --
> Cheers,
> Lyude Paul
--
Best regards,
Wayne Lin
^ permalink raw reply [flat|nested] 12+ messages in thread
* 回覆: [PATCH] drm/dp_mst: Avoid NULL pointer dereference
@ 2020-01-06 7:34 ` Lin, Wayne
0 siblings, 0 replies; 12+ messages in thread
From: Lin, Wayne @ 2020-01-06 7:34 UTC (permalink / raw)
To: Lyude Paul, dri-devel, amd-gfx
Cc: Zuo, Jerry, Lipski, Mikita, Kazlauskas, Nicholas, stable
[AMD Public Use]
> -----原始郵件-----
> 寄件者: Lyude Paul <lyude@redhat.com>
> 寄件日期: Saturday, January 4, 2020 4:35 AM
> 收件者: Lin, Wayne <Wayne.Lin@amd.com>; dri-
> devel@lists.freedesktop.org; amd-gfx@lists.freedesktop.org
> 副本: Kazlauskas, Nicholas <Nicholas.Kazlauskas@amd.com>; Wentland,
> Harry <Harry.Wentland@amd.com>; Lipski, Mikita <Mikita.Lipski@amd.com>;
> Zuo, Jerry <Jerry.Zuo@amd.com>; stable@vger.kernel.org
> 主旨: Re: [PATCH] drm/dp_mst: Avoid NULL pointer dereference
>
> Back from the holidays!
>
> Reviewed-by: Lyude Paul <lyude@redhat.com>
>
> Do you need me to push this to drm-misc?
>
Thanks for your time!
And yes, please help to push this to drm-misc.
> On Thu, 2019-12-26 at 10:31 +0800, Wayne Lin wrote:
> > [Why]
> > Found kernel NULL pointer dereference under the below situation:
> >
> > src — HDMI_Monitor src — HDMI_Monitor
> > e.g.: \ =>
> > MSTB — MSTB (unplug) MSTB — MSTB
> >
> > When display 1 HDMI and 2 DP daisy chain monitors, unplugging the dp
> > cable connected to source causes kernel NULL pointer dereference at
> > drm_dp_mst_atomic_check_bw_limit(). When calculating pbn_limit, if
> > branch is null, accessing "&branch->ports" causes the problem.
> >
> > [How]
> > Judge branch is null or not at the beginning. If it is null, return 0.
> >
> > Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
> > Cc: stable@vger.kernel.org
> > ---
> > drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c
> > b/drivers/gpu/drm/drm_dp_mst_topology.c
> > index 7d2d31eaf003..a6473e3ab448 100644
> > --- a/drivers/gpu/drm/drm_dp_mst_topology.c
> > +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
> > @@ -4707,6 +4707,9 @@ int drm_dp_mst_atomic_check_bw_limit(struct
> > drm_dp_mst_branch *branch,
> > struct drm_dp_vcpi_allocation *vcpi;
> > int pbn_limit = 0, pbn_used = 0;
> >
> > + if (!branch)
> > + return 0;
> > +
> > list_for_each_entry(port, &branch->ports, next) {
> > if (port->mstb)
> > if (drm_dp_mst_atomic_check_bw_limit(port->mstb,
> > mst_state))
> --
> Cheers,
> Lyude Paul
--
Best regards,
Wayne Lin
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply [flat|nested] 12+ messages in thread
* 回覆: [PATCH] drm/dp_mst: Avoid NULL pointer dereference
@ 2020-01-06 7:34 ` Lin, Wayne
0 siblings, 0 replies; 12+ messages in thread
From: Lin, Wayne @ 2020-01-06 7:34 UTC (permalink / raw)
To: Lyude Paul, dri-devel, amd-gfx
Cc: Zuo, Jerry, Lipski, Mikita, Wentland, Harry, Kazlauskas,
Nicholas, stable
[AMD Public Use]
> -----原始郵件-----
> 寄件者: Lyude Paul <lyude@redhat.com>
> 寄件日期: Saturday, January 4, 2020 4:35 AM
> 收件者: Lin, Wayne <Wayne.Lin@amd.com>; dri-
> devel@lists.freedesktop.org; amd-gfx@lists.freedesktop.org
> 副本: Kazlauskas, Nicholas <Nicholas.Kazlauskas@amd.com>; Wentland,
> Harry <Harry.Wentland@amd.com>; Lipski, Mikita <Mikita.Lipski@amd.com>;
> Zuo, Jerry <Jerry.Zuo@amd.com>; stable@vger.kernel.org
> 主旨: Re: [PATCH] drm/dp_mst: Avoid NULL pointer dereference
>
> Back from the holidays!
>
> Reviewed-by: Lyude Paul <lyude@redhat.com>
>
> Do you need me to push this to drm-misc?
>
Thanks for your time!
And yes, please help to push this to drm-misc.
> On Thu, 2019-12-26 at 10:31 +0800, Wayne Lin wrote:
> > [Why]
> > Found kernel NULL pointer dereference under the below situation:
> >
> > src — HDMI_Monitor src — HDMI_Monitor
> > e.g.: \ =>
> > MSTB — MSTB (unplug) MSTB — MSTB
> >
> > When display 1 HDMI and 2 DP daisy chain monitors, unplugging the dp
> > cable connected to source causes kernel NULL pointer dereference at
> > drm_dp_mst_atomic_check_bw_limit(). When calculating pbn_limit, if
> > branch is null, accessing "&branch->ports" causes the problem.
> >
> > [How]
> > Judge branch is null or not at the beginning. If it is null, return 0.
> >
> > Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
> > Cc: stable@vger.kernel.org
> > ---
> > drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c
> > b/drivers/gpu/drm/drm_dp_mst_topology.c
> > index 7d2d31eaf003..a6473e3ab448 100644
> > --- a/drivers/gpu/drm/drm_dp_mst_topology.c
> > +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
> > @@ -4707,6 +4707,9 @@ int drm_dp_mst_atomic_check_bw_limit(struct
> > drm_dp_mst_branch *branch,
> > struct drm_dp_vcpi_allocation *vcpi;
> > int pbn_limit = 0, pbn_used = 0;
> >
> > + if (!branch)
> > + return 0;
> > +
> > list_for_each_entry(port, &branch->ports, next) {
> > if (port->mstb)
> > if (drm_dp_mst_atomic_check_bw_limit(port->mstb,
> > mst_state))
> --
> Cheers,
> Lyude Paul
--
Best regards,
Wayne Lin
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2020-01-06 7:35 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-12-26 2:31 [PATCH] drm/dp_mst: Avoid NULL pointer dereference Wayne Lin
2019-12-26 2:31 ` Wayne Lin
2019-12-26 2:31 ` Wayne Lin
2019-12-26 15:04 ` Lipski, Mikita
2019-12-26 15:04 ` Lipski, Mikita
2019-12-26 15:04 ` Lipski, Mikita
2020-01-03 20:35 ` Lyude Paul
2020-01-03 20:35 ` Lyude Paul
2020-01-03 20:35 ` Lyude Paul
2020-01-06 7:34 ` 回覆: " Lin, Wayne
2020-01-06 7:34 ` Lin, Wayne
2020-01-06 7:34 ` Lin, Wayne
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