drm/nouveau/mem: guard against NULL pointer access in mem_del

karolherbst · airlied · commit d10285a25e29 · 2020-10-07T15:33:09.000+10:00
other drivers seems to do something similar Signed-off-by: Karol Herbst <kherbst@redhat.com> Cc: dri-devel <dri-devel@lists.freedesktop.org> Cc: Dave Airlie <airlied@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20201006220528.13925-2-kherbst@redhat.com
diff --git a/drivers/gpu/drm/nouveau/nouveau_mem.c b/drivers/gpu/drm/nouveau/nouveau_mem.c
@@ -176,6 +176,8 @@ void
 nouveau_mem_del(struct ttm_mem_reg *reg)
 {
 	struct nouveau_mem *mem = nouveau_mem(reg);
+	if (!mem)
+		return;
 	nouveau_mem_fini(mem);
 	kfree(reg->mm_node);
 	reg->mm_node = NULL;

Original file line number	Diff line number	Diff line change
`@@ -176,6 +176,8 @@ void`
`176`	`176`	`nouveau_mem_del(struct ttm_mem_reg *reg)`
`177`	`177`	`{`
`178`	`178`	`struct nouveau_mem *mem = nouveau_mem(reg);`
	`179`	`+ if (!mem)`
	`180`	`+ return;`
`179`	`181`	`nouveau_mem_fini(mem);`
`180`	`182`	`kfree(reg->mm_node);`
`181`	`183`	`reg->mm_node = NULL;`