diff mbox series

[next] drm/atomic: avoid null pointer dereference on pointer crtc

Message ID 20201116110316.269934-1-colin.king@canonical.com (mailing list archive)
State New, archived
Headers show
Series [next] drm/atomic: avoid null pointer dereference on pointer crtc | expand

Commit Message

Colin King Nov. 16, 2020, 11:03 a.m. UTC 
From: Colin Ian King <colin.king@canonical.com>

Since moving to the new debug helper functions we now have a debug message
that dereferences crtc to print a kernel debug message when crtc is null
and so this debug message will now cause a null pointer dereference. Since
this is a debug message it probably is just simplest to fix this by just
removing the debug message altogether.

Addresses-Coverity: ("Dereference after null check")
Fixes: e3aae683e861 ("drm: convert drm_atomic_uapi.c to new debug helpers")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/gpu/drm/drm_atomic_uapi.c | 5 -----
 1 file changed, 5 deletions(-)

Comments

Simon Ser Nov. 16, 2020, 11:08 a.m. UTC | #1 
On Monday, November 16, 2020 12:03 PM, Colin King <colin.king@canonical.com> wrote:

> From: Colin Ian King colin.king@canonical.com
>
> Since moving to the new debug helper functions we now have a debug message
> that dereferences crtc to print a kernel debug message when crtc is null
> and so this debug message will now cause a null pointer dereference. Since
> this is a debug message it probably is just simplest to fix this by just
> removing the debug message altogether.

NACK. This removes the log altogether instead of fixing it.

A fix has already been pushed to drm-misc-next: 0003b687ee6d ("drm: fix
oops in drm_atomic_set_crtc_for_connector").
Colin King Nov. 16, 2020, 11:28 a.m. UTC | #2 
On 16/11/2020 11:08, Simon Ser wrote:
> On Monday, November 16, 2020 12:03 PM, Colin King <colin.king@canonical.com> wrote:
> 
>> From: Colin Ian King colin.king@canonical.com
>>
>> Since moving to the new debug helper functions we now have a debug message
>> that dereferences crtc to print a kernel debug message when crtc is null
>> and so this debug message will now cause a null pointer dereference. Since
>> this is a debug message it probably is just simplest to fix this by just
>> removing the debug message altogether.
> 
> NACK. This removes the log altogether instead of fixing it.
> 
> A fix has already been pushed to drm-misc-next: 0003b687ee6d ("drm: fix
> oops in drm_atomic_set_crtc_for_connector").
> 
Good to see this has already been fixed. Thanks.

Colin
diff mbox series

Patch

diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index 9df7f2a170e3..3fd84590560a 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -338,11 +338,6 @@  drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
 			       "Link [CONNECTOR:%d:%s] state %p to [CRTC:%d:%s]\n",
 			       connector->base.id, connector->name,
 			       conn_state, crtc->base.id, crtc->name);
-	} else {
-		drm_dbg_atomic(crtc->dev,
-			       "Link [CONNECTOR:%d:%s] state %p to [NOCRTC]\n",
-			       connector->base.id, connector->name,
-			       conn_state);
 	}
 
 	return 0;