The Parfait (version 2.1.0) static code analysis tool found multiple NULL
pointer derefernce problems.
- drivers/gpu/drm/drm_dp_mst_topology.c
The call to drm_dp_calculate_rad() in function drm_dp_port_setup_pdt()
could result in a NULL pointer being returned to port->mstb due to a
failure to allocate memory for port->mstb.
- drivers/gpu/drm/drm_drv.c
Any calls to drm_minor_get_slot() could result in the return of a NULL
pointer when an invalid DRM device type is encountered. 2 helper
functions where added for pointer manipulation (drm_minor_get_slot()
and drm_minor_set_minor()) along with checks for valid pointers for
struct drm_device variables throughout this module.
- drivers/gpu/drm/drm_edid.c
The call to drm_cvt_mode() in function drm_mode_std() for the
HDTV hack resulted in the possibility of accessing a NULL pointer
if drm_mode_std() returned NULL. A check for this added right after
the call to drm_cvt_mode() in this particular area of code.
- drivers/gpu/drm/drm_vblank.c
Null pointer checks were added to return values from calls to
drm_crtc_from_index(). There is a possibility, however minute, that
crtc->index may not be found when trying to find the struct crtc
from it's assigned index given in drm_crtc_init_with_planes().
3 return checks for NULL where added.
Signed-off-by: Joe Moriarty <joe.moriarty@xxxxxxxxxx>
Reviewed-by: Steven Sistare <steven.sistare@xxxxxxxxxx>
---
drivers/gpu/drm/drm_dp_mst_topology.c | 8 +++++---
drivers/gpu/drm/drm_drv.c | 38 +++++++++++++++++++++++++++++++----
drivers/gpu/drm/drm_edid.c | 2 ++
drivers/gpu/drm/drm_vblank.c | 6 +++---
4 files changed, 44 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 70dcfa58d3c2..ec503d416062 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -1082,10 +1082,12 @@ static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
lct = drm_dp_calculate_rad(port, rad);
port->mstb = drm_dp_add_mst_branch_device(lct, rad);
- port->mstb->mgr = port->mgr;
- port->mstb->port_parent = port;
+ if (port->mstb) {
+ port->mstb->mgr = port->mgr;
+ port->mstb->port_parent = port;
- send_link = true;
+ send_link = true;
+ }
break;
}
return send_link;
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 9acc1e157813..938eee77f014 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -99,10 +99,36 @@ static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
case DRM_MINOR_CONTROL:
return &dev->control;
default:
+ DRM_ERROR("Error in %s: Invalid dev, type = %d\n",
+ __func__, type);
return NULL;
}
}
+static inline int drm_minor_set_minor(struct drm_device *dev,
+ unsigned int type,
+ struct drm_minor *minor)
+{
+ struct drm_minor **slot = drm_minor_get_slot(dev, type);
+ int retval = -ENODEV;
+
+ if (slot) {
+ retval = 0;
+ *slot = minor;
+ }
+ return retval;
+}
+
+static inline struct drm_minor *drm_minor_get_minor(struct drm_device *dev,
+ unsigned int type)
+{
+ struct drm_minor **slot = drm_minor_get_slot(dev, type);
+
+ if (slot)
+ return *slot;
+ return NULL;
+}
+
static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
{
struct drm_minor *minor;
@@ -137,8 +163,9 @@ static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
goto err_index;
}
- *drm_minor_get_slot(dev, type) = minor;
- return 0;
+ r = drm_minor_set_minor(dev, type, minor);
+ if (r == 0)
+ return r;
err_index:
spin_lock_irqsave(&drm_minor_lock, flags);
@@ -155,6 +182,9 @@ static void drm_minor_free(struct drm_device *dev, unsigned int type)
unsigned long flags;
slot = drm_minor_get_slot(dev, type);
+ if (!slot)
+ return
+
minor = *slot;
if (!minor)
return;
@@ -177,7 +207,7 @@ static int drm_minor_register(struct drm_device *dev, unsigned int type)
DRM_DEBUG("\n");
- minor = *drm_minor_get_slot(dev, type);
+ minor = drm_minor_get_slot(dev, type);
if (!minor)
return 0;
@@ -209,7 +239,7 @@ static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
struct drm_minor *minor;
unsigned long flags;
- minor = *drm_minor_get_slot(dev, type);
+ minor = drm_minor_get_slot(dev, type);
if (!minor || !device_is_registered(minor->kdev))
return;
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index ddd537914575..23c9977d8999 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -2083,6 +2083,8 @@ drm_mode_std(struct drm_connector *connector, struct edid *edid,
if (hsize == 1366 && vsize == 768 && vrefresh_rate == 60) {
mode = drm_cvt_mode(dev, 1366, 768, vrefresh_rate, 0, 0,
false);
+ if (!mode)
+ return NULL;
mode->hdisplay = 1366;
mode->hsync_start = mode->hsync_start - 1;
mode->hsync_end = mode->hsync_end - 1;
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index 32d9bcf5be7f..a3a1bce87468 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -120,7 +120,7 @@ static u32 __get_vblank_counter(struct drm_device *dev, unsigned int pipe)
if (drm_core_check_feature(dev, DRIVER_MODESET)) {
struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
- if (crtc->funcs->get_vblank_counter)
+ if (crtc && crtc->funcs->get_vblank_counter)
return crtc->funcs->get_vblank_counter(crtc);
}
@@ -318,7 +318,7 @@ static void __disable_vblank(struct drm_device *dev, unsigned int pipe)
if (drm_core_check_feature(dev, DRIVER_MODESET)) {
struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
- if (crtc->funcs->disable_vblank) {
+ if (crtc && crtc->funcs->disable_vblank) {
crtc->funcs->disable_vblank(crtc);
return;
}
@@ -918,7 +918,7 @@ static int __enable_vblank(struct drm_device *dev, unsigned int pipe)
if (drm_core_check_feature(dev, DRIVER_MODESET)) {
struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
- if (crtc->funcs->enable_vblank)
+ if (crtc && crtc->funcs->enable_vblank)
return crtc->funcs->enable_vblank(crtc);
}
--
2.15.0
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