drm: block userspace under allocating buffer and having drivers overwrite it (v2)

With the current screwed but its ABI, ioctls for the drm, Linus pointed out that we could allow userspace to specify the allocation size, but we pass it to the driver which then uses it blindly to store a struct. Now if userspace specifies the allocation size as smaller than the driver needs, the driver can possibly overwrite memory.

This patch restructures the driver ioctls so we store the structure size we are expecting, and make sure we allocate at least that size. The copy from/to userspace are still restricted to the size the user specifies, this allows ioctl structs to grow on both sides of the equation.

Up until now we didn't really use the DRM_IOCTL defines in the kernel, so this cleans them up and adds them for nouveau.

v2:
fix nouveau pushbuf arg (thanks to Ben for pointing it out)

Reported-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

7 files changed, 39 insertions, 23 deletions

diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 2a512bc..7809d23 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -305,14 +305,16 @@ struct drm_ioctl_desc {
 	unsigned int cmd;
 	int flags;
 	drm_ioctl_t *func;
+	unsigned int cmd_drv;
 };
 
 /**
  * Creates a driver or general drm_ioctl_desc array entry for the given
  * ioctl, for use by drm_ioctl().
  */
-#define DRM_IOCTL_DEF(ioctl, _func, _flags) \
-	[DRM_IOCTL_NR(ioctl)] = {.cmd = ioctl, .func = _func, .flags = _flags}
+
+#define DRM_IOCTL_DEF_DRV(ioctl, _func, _flags)			\
+	[DRM_IOCTL_NR(DRM_##ioctl)] = {.cmd = DRM_##ioctl, .func = _func, .flags = _flags, .cmd_drv = DRM_IOCTL_##ioctl}
 
 struct drm_magic_entry {
 	struct list_head head;
diff --git a/include/drm/i830_drm.h b/include/drm/i830_drm.h
index 4b00d2d..61315c2 100644
--- a/include/drm/i830_drm.h
+++ b/include/drm/i830_drm.h
@@ -264,20 +264,20 @@ typedef struct _drm_i830_sarea {
 #define DRM_I830_GETPARAM	0x0c
 #define DRM_I830_SETPARAM	0x0d
 
-#define DRM_IOCTL_I830_INIT		DRM_IOW( DRM_COMMAND_BASE + DRM_IOCTL_I830_INIT, drm_i830_init_t)
-#define DRM_IOCTL_I830_VERTEX		DRM_IOW( DRM_COMMAND_BASE + DRM_IOCTL_I830_VERTEX, drm_i830_vertex_t)
-#define DRM_IOCTL_I830_CLEAR		DRM_IOW( DRM_COMMAND_BASE + DRM_IOCTL_I830_CLEAR, drm_i830_clear_t)
-#define DRM_IOCTL_I830_FLUSH		DRM_IO ( DRM_COMMAND_BASE + DRM_IOCTL_I830_FLUSH)
-#define DRM_IOCTL_I830_GETAGE		DRM_IO ( DRM_COMMAND_BASE + DRM_IOCTL_I830_GETAGE)
-#define DRM_IOCTL_I830_GETBUF		DRM_IOWR(DRM_COMMAND_BASE + DRM_IOCTL_I830_GETBUF, drm_i830_dma_t)
-#define DRM_IOCTL_I830_SWAP		DRM_IO ( DRM_COMMAND_BASE + DRM_IOCTL_I830_SWAP)
-#define DRM_IOCTL_I830_COPY		DRM_IOW( DRM_COMMAND_BASE + DRM_IOCTL_I830_COPY, drm_i830_copy_t)
-#define DRM_IOCTL_I830_DOCOPY		DRM_IO ( DRM_COMMAND_BASE + DRM_IOCTL_I830_DOCOPY)
-#define DRM_IOCTL_I830_FLIP		DRM_IO ( DRM_COMMAND_BASE + DRM_IOCTL_I830_FLIP)
-#define DRM_IOCTL_I830_IRQ_EMIT         DRM_IOWR(DRM_COMMAND_BASE + DRM_IOCTL_I830_IRQ_EMIT, drm_i830_irq_emit_t)
-#define DRM_IOCTL_I830_IRQ_WAIT         DRM_IOW( DRM_COMMAND_BASE + DRM_IOCTL_I830_IRQ_WAIT, drm_i830_irq_wait_t)
-#define DRM_IOCTL_I830_GETPARAM         DRM_IOWR(DRM_COMMAND_BASE + DRM_IOCTL_I830_GETPARAM, drm_i830_getparam_t)
-#define DRM_IOCTL_I830_SETPARAM         DRM_IOWR(DRM_COMMAND_BASE + DRM_IOCTL_I830_SETPARAM, drm_i830_setparam_t)
+#define DRM_IOCTL_I830_INIT		DRM_IOW( DRM_COMMAND_BASE + DRM_I830_INIT, drm_i830_init_t)
+#define DRM_IOCTL_I830_VERTEX		DRM_IOW( DRM_COMMAND_BASE + DRM_I830_VERTEX, drm_i830_vertex_t)
+#define DRM_IOCTL_I830_CLEAR		DRM_IOW( DRM_COMMAND_BASE + DRM_I830_CLEAR, drm_i830_clear_t)
+#define DRM_IOCTL_I830_FLUSH		DRM_IO ( DRM_COMMAND_BASE + DRM_I830_FLUSH)
+#define DRM_IOCTL_I830_GETAGE		DRM_IO ( DRM_COMMAND_BASE + DRM_I830_GETAGE)
+#define DRM_IOCTL_I830_GETBUF		DRM_IOWR(DRM_COMMAND_BASE + DRM_I830_GETBUF, drm_i830_dma_t)
+#define DRM_IOCTL_I830_SWAP		DRM_IO ( DRM_COMMAND_BASE + DRM_I830_SWAP)
+#define DRM_IOCTL_I830_COPY		DRM_IOW( DRM_COMMAND_BASE + DRM_I830_COPY, drm_i830_copy_t)
+#define DRM_IOCTL_I830_DOCOPY		DRM_IO ( DRM_COMMAND_BASE + DRM_I830_DOCOPY)
+#define DRM_IOCTL_I830_FLIP		DRM_IO ( DRM_COMMAND_BASE + DRM_I830_FLIP)
+#define DRM_IOCTL_I830_IRQ_EMIT         DRM_IOWR(DRM_COMMAND_BASE + DRM_I830_IRQ_EMIT, drm_i830_irq_emit_t)
+#define DRM_IOCTL_I830_IRQ_WAIT         DRM_IOW( DRM_COMMAND_BASE + DRM_I830_IRQ_WAIT, drm_i830_irq_wait_t)
+#define DRM_IOCTL_I830_GETPARAM         DRM_IOWR(DRM_COMMAND_BASE + DRM_I830_GETPARAM, drm_i830_getparam_t)
+#define DRM_IOCTL_I830_SETPARAM         DRM_IOWR(DRM_COMMAND_BASE + DRM_I830_SETPARAM, drm_i830_setparam_t)
 
 typedef struct _drm_i830_clear {
 	int clear_color;
diff --git a/include/drm/i915_drm.h b/include/drm/i915_drm.h
index 7f0028e..000357b 100644
--- a/include/drm/i915_drm.h
+++ b/include/drm/i915_drm.h
@@ -206,6 +206,7 @@ typedef struct _drm_i915_sarea {
 #define DRM_IOCTL_I915_SET_VBLANK_PIPE	DRM_IOW( DRM_COMMAND_BASE + DRM_I915_SET_VBLANK_PIPE, drm_i915_vblank_pipe_t)
 #define DRM_IOCTL_I915_GET_VBLANK_PIPE	DRM_IOR( DRM_COMMAND_BASE + DRM_I915_GET_VBLANK_PIPE, drm_i915_vblank_pipe_t)
 #define DRM_IOCTL_I915_VBLANK_SWAP	DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_VBLANK_SWAP, drm_i915_vblank_swap_t)
+#define DRM_IOCTL_I915_HWS_ADDR		DRM_IOW(DRM_COMMAND_BASE + DRM_I915_HWS_ADDR, struct drm_i915_gem_init)
 #define DRM_IOCTL_I915_GEM_INIT		DRM_IOW(DRM_COMMAND_BASE + DRM_I915_GEM_INIT, struct drm_i915_gem_init)
 #define DRM_IOCTL_I915_GEM_EXECBUFFER	DRM_IOW(DRM_COMMAND_BASE + DRM_I915_GEM_EXECBUFFER, struct drm_i915_gem_execbuffer)
 #define DRM_IOCTL_I915_GEM_EXECBUFFER2	DRM_IOW(DRM_COMMAND_BASE + DRM_I915_GEM_EXECBUFFER2, struct drm_i915_gem_execbuffer2)
diff --git a/include/drm/mga_drm.h b/include/drm/mga_drm.h
index 3ffbc47..c16097f 100644
--- a/include/drm/mga_drm.h
+++ b/include/drm/mga_drm.h
@@ -248,7 +248,7 @@ typedef struct _drm_mga_sarea {
 #define DRM_MGA_DMA_BOOTSTRAP  0x0c
 
 #define DRM_IOCTL_MGA_INIT     DRM_IOW( DRM_COMMAND_BASE + DRM_MGA_INIT, drm_mga_init_t)
-#define DRM_IOCTL_MGA_FLUSH    DRM_IOW( DRM_COMMAND_BASE + DRM_MGA_FLUSH, drm_lock_t)
+#define DRM_IOCTL_MGA_FLUSH    DRM_IOW( DRM_COMMAND_BASE + DRM_MGA_FLUSH, struct drm_lock)
 #define DRM_IOCTL_MGA_RESET    DRM_IO(  DRM_COMMAND_BASE + DRM_MGA_RESET)
 #define DRM_IOCTL_MGA_SWAP     DRM_IO(  DRM_COMMAND_BASE + DRM_MGA_SWAP)
 #define DRM_IOCTL_MGA_CLEAR    DRM_IOW( DRM_COMMAND_BASE + DRM_MGA_CLEAR, drm_mga_clear_t)
diff --git a/include/drm/nouveau_drm.h b/include/drm/nouveau_drm.h
index fe917de..01a7141 100644
--- a/include/drm/nouveau_drm.h
+++ b/include/drm/nouveau_drm.h
@@ -197,4 +197,17 @@ struct drm_nouveau_sarea {
 #define DRM_NOUVEAU_GEM_CPU_FINI       0x43
 #define DRM_NOUVEAU_GEM_INFO           0x44
 
+#define DRM_IOCTL_NOUVEAU_GETPARAM           DRM_IOWR(DRM_COMMAND_BASE + DRM_NOUVEAU_GETPARAM, struct drm_nouveau_getparam)
+#define DRM_IOCTL_NOUVEAU_SETPARAM           DRM_IOWR(DRM_COMMAND_BASE + DRM_NOUVEAU_SETPARAM, struct drm_nouveau_setparam)
+#define DRM_IOCTL_NOUVEAU_CHANNEL_ALLOC      DRM_IOWR(DRM_COMMAND_BASE + DRM_NOUVEAU_CHANNEL_ALLOC, struct drm_nouveau_channel_alloc)
+#define DRM_IOCTL_NOUVEAU_CHANNEL_FREE       DRM_IOW (DRM_COMMAND_BASE + DRM_NOUVEAU_CHANNEL_FREE, struct drm_nouveau_channel_free)
+#define DRM_IOCTL_NOUVEAU_GROBJ_ALLOC        DRM_IOW (DRM_COMMAND_BASE + DRM_NOUVEAU_GROBJ_ALLOC, struct drm_nouveau_grobj_alloc)
+#define DRM_IOCTL_NOUVEAU_NOTIFIEROBJ_ALLOC  DRM_IOWR(DRM_COMMAND_BASE + DRM_NOUVEAU_NOTIFIEROBJ_ALLOC, struct drm_nouveau_notifierobj_alloc)
+#define DRM_IOCTL_NOUVEAU_GPUOBJ_FREE        DRM_IOW (DRM_COMMAND_BASE + DRM_NOUVEAU_GPUOBJ_FREE, struct drm_nouveau_gpuobj_free)
+#define DRM_IOCTL_NOUVEAU_GEM_NEW            DRM_IOWR(DRM_COMMAND_BASE + DRM_NOUVEAU_GEM_NEW, struct drm_nouveau_gem_new)
+#define DRM_IOCTL_NOUVEAU_GEM_PUSHBUF        DRM_IOWR(DRM_COMMAND_BASE + DRM_NOUVEAU_GEM_PUSHBUF, struct drm_nouveau_gem_pushbuf)
+#define DRM_IOCTL_NOUVEAU_GEM_CPU_PREP       DRM_IOW (DRM_COMMAND_BASE + DRM_NOUVEAU_GEM_CPU_PREP, struct drm_nouveau_gem_cpu_prep)
+#define DRM_IOCTL_NOUVEAU_GEM_CPU_FINI       DRM_IOW (DRM_COMMAND_BASE + DRM_NOUVEAU_GEM_CPU_FINI, struct drm_nouveau_gem_cpu_fini)
+#define DRM_IOCTL_NOUVEAU_GEM_INFO           DRM_IOWR(DRM_COMMAND_BASE + DRM_NOUVEAU_GEM_INFO, struct drm_nouveau_gem_info)
+
 #endif /* __NOUVEAU_DRM_H__ */
diff --git a/include/drm/radeon_drm.h b/include/drm/radeon_drm.h
index 0acaf8f..10f8b53 100644
--- a/include/drm/radeon_drm.h
+++ b/include/drm/radeon_drm.h
@@ -547,8 +547,8 @@ typedef struct {
 #define DRM_IOCTL_RADEON_GEM_WAIT_IDLE	DRM_IOW(DRM_COMMAND_BASE + DRM_RADEON_GEM_WAIT_IDLE, struct drm_radeon_gem_wait_idle)
 #define DRM_IOCTL_RADEON_CS		DRM_IOWR(DRM_COMMAND_BASE + DRM_RADEON_CS, struct drm_radeon_cs)
 #define DRM_IOCTL_RADEON_INFO		DRM_IOWR(DRM_COMMAND_BASE + DRM_RADEON_INFO, struct drm_radeon_info)
-#define DRM_IOCTL_RADEON_SET_TILING	DRM_IOWR(DRM_COMMAND_BASE + DRM_RADEON_GEM_SET_TILING, struct drm_radeon_gem_set_tiling)
-#define DRM_IOCTL_RADEON_GET_TILING	DRM_IOWR(DRM_COMMAND_BASE + DRM_RADEON_GEM_GET_TILING, struct drm_radeon_gem_get_tiling)
+#define DRM_IOCTL_RADEON_GEM_SET_TILING	DRM_IOWR(DRM_COMMAND_BASE + DRM_RADEON_GEM_SET_TILING, struct drm_radeon_gem_set_tiling)
+#define DRM_IOCTL_RADEON_GEM_GET_TILING	DRM_IOWR(DRM_COMMAND_BASE + DRM_RADEON_GEM_GET_TILING, struct drm_radeon_gem_get_tiling)
 #define DRM_IOCTL_RADEON_GEM_BUSY	DRM_IOWR(DRM_COMMAND_BASE + DRM_RADEON_GEM_BUSY, struct drm_radeon_gem_busy)
 
 typedef struct drm_radeon_init {
diff --git a/include/drm/savage_drm.h b/include/drm/savage_drm.h
index 8a576ef..4863cf6 100644
--- a/include/drm/savage_drm.h
+++ b/include/drm/savage_drm.h
@@ -63,10 +63,10 @@ typedef struct _drm_savage_sarea {
 #define DRM_SAVAGE_BCI_EVENT_EMIT	0x02
 #define DRM_SAVAGE_BCI_EVENT_WAIT	0x03
 
-#define DRM_IOCTL_SAVAGE_INIT		DRM_IOW( DRM_COMMAND_BASE + DRM_SAVAGE_BCI_INIT, drm_savage_init_t)
-#define DRM_IOCTL_SAVAGE_CMDBUF		DRM_IOW( DRM_COMMAND_BASE + DRM_SAVAGE_BCI_CMDBUF, drm_savage_cmdbuf_t)
-#define DRM_IOCTL_SAVAGE_EVENT_EMIT	DRM_IOWR(DRM_COMMAND_BASE + DRM_SAVAGE_BCI_EVENT_EMIT, drm_savage_event_emit_t)
-#define DRM_IOCTL_SAVAGE_EVENT_WAIT	DRM_IOW( DRM_COMMAND_BASE + DRM_SAVAGE_BCI_EVENT_WAIT, drm_savage_event_wait_t)
+#define DRM_IOCTL_SAVAGE_BCI_INIT		DRM_IOW( DRM_COMMAND_BASE + DRM_SAVAGE_BCI_INIT, drm_savage_init_t)
+#define DRM_IOCTL_SAVAGE_BCI_CMDBUF		DRM_IOW( DRM_COMMAND_BASE + DRM_SAVAGE_BCI_CMDBUF, drm_savage_cmdbuf_t)
+#define DRM_IOCTL_SAVAGE_BCI_EVENT_EMIT	DRM_IOWR(DRM_COMMAND_BASE + DRM_SAVAGE_BCI_EVENT_EMIT, drm_savage_event_emit_t)
+#define DRM_IOCTL_SAVAGE_BCI_EVENT_WAIT	DRM_IOW( DRM_COMMAND_BASE + DRM_SAVAGE_BCI_EVENT_WAIT, drm_savage_event_wait_t)
 
 #define SAVAGE_DMA_PCI	1
 #define SAVAGE_DMA_AGP	3