[PATCH 5.10 015/294] drm/vmwgfx/vmwgfx_cmdbuf_res: Remove unused variable ret

[PATCH 5.10 015/294] drm/vmwgfx/vmwgfx_cmdbuf_res: Remove unused variable ret

[Greg Kroah-Hartman]

5.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Lee Jones <lee.jones@linaro.org>

[ Upstream commit 43ebfe61c3928573a5ef8d80c2f5300aa5c904c0 ]

Fixes the following W=1 kernel build warning(s):

 drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf_res.c: In function ‘vmw_cmdbuf_res_revert’:
 drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf_res.c:162:6: warning: variable ‘ret’ set but not used [-Wunused-but-set-variable]

Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Cc: Roland Scheidegger <sroland@vmware.com>
Cc: Zack Rusin <zackr@vmware.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Zack Rusin <zackr@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210115181313.3431493-40-lee.jones@linaro.org
Stable-dep-of: 517621b70600 ("drm/vmwgfx: Fix possible null pointer derefence with invalid contexts")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf_res.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf_res.c b/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf_res.c
index 44d858ce4ce7f..47b92d0c898a7 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf_res.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf_res.c
@@ -160,7 +160,6 @@ void vmw_cmdbuf_res_commit(struct list_head *list)
 void vmw_cmdbuf_res_revert(struct list_head *list)
 {
 	struct vmw_cmdbuf_res *entry, *next;
-	int ret;
 
 	list_for_each_entry_safe(entry, next, list, head) {
 		switch (entry->state) {
@@ -168,8 +167,7 @@ void vmw_cmdbuf_res_revert(struct list_head *list)
 			vmw_cmdbuf_res_free(entry->man, entry);
 			break;
 		case VMW_CMDBUF_RES_DEL:
-			ret = drm_ht_insert_item(&entry->man->resources,
-						 &entry->hash);
+			drm_ht_insert_item(&entry->man->resources, &entry->hash);
 			list_del(&entry->head);
 			list_add_tail(&entry->head, &entry->man->list);
 			entry->state = VMW_CMDBUF_RES_COMMITTED;
-- 
2.43.0

[PATCH 5.10 017/294] drm/vmwgfx: Fix possible null pointer derefence with invalid contexts

[Greg Kroah-Hartman]

5.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Zack Rusin <zack.rusin@broadcom.com>

[ Upstream commit 517621b7060096e48e42f545fa6646fc00252eac ]

vmw_context_cotable can return either an error or a null pointer and its
usage sometimes went unchecked. Subsequent code would then try to access
either a null pointer or an error value.

The invalid dereferences were only possible with malformed userspace
apps which never properly initialized the rendering contexts.

Check the results of vmw_context_cotable to fix the invalid derefs.

Thanks:
ziming zhang(@ezrak1e) from Ant Group Light-Year Security Lab
who was the first person to discover it.
Niels De Graef who reported it and helped to track down the poc.

Fixes: 9c079b8ce8bf ("drm/vmwgfx: Adapt execbuf to the new validation api")
Cc: <stable@vger.kernel.org> # v4.20+
Reported-by: Niels De Graef  <ndegraef@redhat.com>
Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>
Cc: Martin Krastev <martin.krastev@broadcom.com>
Cc: Maaz Mombasawala <maaz.mombasawala@broadcom.com>
Cc: Ian Forbes <ian.forbes@broadcom.com>
Cc: Broadcom internal kernel review list <bcm-kernel-feedback-list@broadcom.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Maaz Mombasawala <maaz.mombasawala@broadcom.com>
Reviewed-by: Martin Krastev <martin.krastev@broadcom.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240110200305.94086-1-zack.rusin@broadcom.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
index 831291b5d1a03..616f6cb622783 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
@@ -467,7 +467,7 @@ static int vmw_resource_context_res_add(struct vmw_private *dev_priv,
 	    vmw_res_type(ctx) == vmw_res_dx_context) {
 		for (i = 0; i < cotable_max; ++i) {
 			res = vmw_context_cotable(ctx, i);
-			if (IS_ERR(res))
+			if (IS_ERR_OR_NULL(res))
 				continue;
 
 			ret = vmw_execbuf_res_noctx_val_add(sw_context, res,
@@ -1272,6 +1272,8 @@ static int vmw_cmd_dx_define_query(struct vmw_private *dev_priv,
 		return -EINVAL;
 
 	cotable_res = vmw_context_cotable(ctx_node->ctx, SVGA_COTABLE_DXQUERY);
+	if (IS_ERR_OR_NULL(cotable_res))
+		return cotable_res ? PTR_ERR(cotable_res) : -EINVAL;
 	ret = vmw_cotable_notify(cotable_res, cmd->body.queryId);
 
 	return ret;
@@ -2450,6 +2452,8 @@ static int vmw_cmd_dx_view_define(struct vmw_private *dev_priv,
 		return ret;
 
 	res = vmw_context_cotable(ctx_node->ctx, vmw_view_cotables[view_type]);
+	if (IS_ERR_OR_NULL(res))
+		return res ? PTR_ERR(res) : -EINVAL;
 	ret = vmw_cotable_notify(res, cmd->defined_id);
 	if (unlikely(ret != 0))
 		return ret;
@@ -2535,8 +2539,8 @@ static int vmw_cmd_dx_so_define(struct vmw_private *dev_priv,
 
 	so_type = vmw_so_cmd_to_type(header->id);
 	res = vmw_context_cotable(ctx_node->ctx, vmw_so_cotables[so_type]);
-	if (IS_ERR(res))
-		return PTR_ERR(res);
+	if (IS_ERR_OR_NULL(res))
+		return res ? PTR_ERR(res) : -EINVAL;
 	cmd = container_of(header, typeof(*cmd), header);
 	ret = vmw_cotable_notify(res, cmd->defined_id);
 
@@ -2655,6 +2659,8 @@ static int vmw_cmd_dx_define_shader(struct vmw_private *dev_priv,
 		return -EINVAL;
 
 	res = vmw_context_cotable(ctx_node->ctx, SVGA_COTABLE_DXSHADER);
+	if (IS_ERR_OR_NULL(res))
+		return res ? PTR_ERR(res) : -EINVAL;
 	ret = vmw_cotable_notify(res, cmd->body.shaderId);
 	if (ret)
 		return ret;
@@ -2976,6 +2982,8 @@ static int vmw_cmd_dx_define_streamoutput(struct vmw_private *dev_priv,
 	}
 
 	res = vmw_context_cotable(ctx_node->ctx, SVGA_COTABLE_STREAMOUTPUT);
+	if (IS_ERR_OR_NULL(res))
+		return res ? PTR_ERR(res) : -EINVAL;
 	ret = vmw_cotable_notify(res, cmd->body.soid);
 	if (ret)
 		return ret;
-- 
2.43.0