Commit 7e9081c5 authored by Gustavo Padovan's avatar Gustavo Padovan

drm/fence: fix memory overwrite when setting out_fence fd

Currently if the userspace declares a int variable to store the out_fence
fd and pass it to OUT_FENCE_PTR the kernel will overwrite the 32 bits
above the int variable on 64 bits systems.

Fix this by making the internal storage of out_fence in the kernel a s32
pointer.
Reported-by: default avatarChad Versace <chadversary@chromium.org>
Signed-off-by: default avatarGustavo Padovan <gustavo.padovan@collabora.com>
Fixes: beaf5af4 ("drm/fence: add out-fences support")
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Rafael Antognolli <rafael.antognolli@intel.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-and-Tested-by: default avatarChad Versace <chadversary@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1484317329-9293-1-git-send-email-gustavo@padovan.org
parent 3846fd9b
...@@ -291,15 +291,15 @@ drm_atomic_get_crtc_state(struct drm_atomic_state *state, ...@@ -291,15 +291,15 @@ drm_atomic_get_crtc_state(struct drm_atomic_state *state,
EXPORT_SYMBOL(drm_atomic_get_crtc_state); EXPORT_SYMBOL(drm_atomic_get_crtc_state);
static void set_out_fence_for_crtc(struct drm_atomic_state *state, static void set_out_fence_for_crtc(struct drm_atomic_state *state,
struct drm_crtc *crtc, s64 __user *fence_ptr) struct drm_crtc *crtc, s32 __user *fence_ptr)
{ {
state->crtcs[drm_crtc_index(crtc)].out_fence_ptr = fence_ptr; state->crtcs[drm_crtc_index(crtc)].out_fence_ptr = fence_ptr;
} }
static s64 __user *get_out_fence_for_crtc(struct drm_atomic_state *state, static s32 __user *get_out_fence_for_crtc(struct drm_atomic_state *state,
struct drm_crtc *crtc) struct drm_crtc *crtc)
{ {
s64 __user *fence_ptr; s32 __user *fence_ptr;
fence_ptr = state->crtcs[drm_crtc_index(crtc)].out_fence_ptr; fence_ptr = state->crtcs[drm_crtc_index(crtc)].out_fence_ptr;
state->crtcs[drm_crtc_index(crtc)].out_fence_ptr = NULL; state->crtcs[drm_crtc_index(crtc)].out_fence_ptr = NULL;
...@@ -512,7 +512,7 @@ int drm_atomic_crtc_set_property(struct drm_crtc *crtc, ...@@ -512,7 +512,7 @@ int drm_atomic_crtc_set_property(struct drm_crtc *crtc,
state->color_mgmt_changed |= replaced; state->color_mgmt_changed |= replaced;
return ret; return ret;
} else if (property == config->prop_out_fence_ptr) { } else if (property == config->prop_out_fence_ptr) {
s64 __user *fence_ptr = u64_to_user_ptr(val); s32 __user *fence_ptr = u64_to_user_ptr(val);
if (!fence_ptr) if (!fence_ptr)
return 0; return 0;
...@@ -1915,7 +1915,7 @@ EXPORT_SYMBOL(drm_atomic_clean_old_fb); ...@@ -1915,7 +1915,7 @@ EXPORT_SYMBOL(drm_atomic_clean_old_fb);
*/ */
struct drm_out_fence_state { struct drm_out_fence_state {
s64 __user *out_fence_ptr; s32 __user *out_fence_ptr;
struct sync_file *sync_file; struct sync_file *sync_file;
int fd; int fd;
}; };
...@@ -1952,7 +1952,7 @@ static int prepare_crtc_signaling(struct drm_device *dev, ...@@ -1952,7 +1952,7 @@ static int prepare_crtc_signaling(struct drm_device *dev,
return 0; return 0;
for_each_crtc_in_state(state, crtc, crtc_state, i) { for_each_crtc_in_state(state, crtc, crtc_state, i) {
u64 __user *fence_ptr; s32 __user *fence_ptr;
fence_ptr = get_out_fence_for_crtc(crtc_state->state, crtc); fence_ptr = get_out_fence_for_crtc(crtc_state->state, crtc);
......
...@@ -144,7 +144,7 @@ struct __drm_crtcs_state { ...@@ -144,7 +144,7 @@ struct __drm_crtcs_state {
struct drm_crtc *ptr; struct drm_crtc *ptr;
struct drm_crtc_state *state; struct drm_crtc_state *state;
struct drm_crtc_commit *commit; struct drm_crtc_commit *commit;
s64 __user *out_fence_ptr; s32 __user *out_fence_ptr;
}; };
struct __drm_connnectors_state { struct __drm_connnectors_state {
......
...@@ -488,7 +488,7 @@ struct drm_mode_config { ...@@ -488,7 +488,7 @@ struct drm_mode_config {
/** /**
* @prop_out_fence_ptr: Sync File fd pointer representing the * @prop_out_fence_ptr: Sync File fd pointer representing the
* outgoing fences for a CRTC. Userspace should provide a pointer to a * outgoing fences for a CRTC. Userspace should provide a pointer to a
* value of type s64, and then cast that pointer to u64. * value of type s32, and then cast that pointer to u64.
*/ */
struct drm_property *prop_out_fence_ptr; struct drm_property *prop_out_fence_ptr;
/** /**
......
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