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authorAndrey Ryabinin <aryabinin@virtuozzo.com>2017-01-26 17:32:11 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-02-14 15:22:52 -0800
commit5b0465dd4ad41705e55fdc2dbe0c8c1e9f88e656 (patch)
tree424c404ac53ec6ce7f033d65d5f93bf3b607ef2a
parenta44ca389a7363b2160b2dd9b81f0175eab78e858 (diff)
drm/i915: fix use-after-free in page_flip_completed()
commit 5351fbb1bf1413f6024892093528280769ca852f upstream. page_flip_completed() dereferences 'work' variable after executing queue_work(). This is not safe as the 'work' item might be already freed by queued work: BUG: KASAN: use-after-free in page_flip_completed+0x3ff/0x490 at addr ffff8803dc010f90 Call Trace: __asan_report_load8_noabort+0x59/0x80 page_flip_completed+0x3ff/0x490 intel_finish_page_flip_mmio+0xe3/0x130 intel_pipe_handle_vblank+0x2d/0x40 gen8_irq_handler+0x4a7/0xed0 __handle_irq_event_percpu+0xf6/0x860 handle_irq_event_percpu+0x6b/0x160 handle_irq_event+0xc7/0x1b0 handle_edge_irq+0x1f4/0xa50 handle_irq+0x41/0x70 do_IRQ+0x9a/0x200 common_interrupt+0x89/0x89 Freed: kfree+0x113/0x4d0 intel_unpin_work_fn+0x29a/0x3b0 process_one_work+0x79e/0x1b70 worker_thread+0x611/0x1460 kthread+0x241/0x3a0 ret_from_fork+0x27/0x40 Move queue_work() after trace_i915_flip_complete() to fix this. Fixes: e5510fac98a7 ("drm/i915: add tracepoints for flip requests & completions") Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/20170126143211.24013-1-aryabinin@virtuozzo.com (cherry picked from commit 05c41f926fcc7ef838c80a6a99d84f67b4e0b824) Signed-off-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/gpu/drm/i915/intel_display.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 909d1d71d130..4f5d07bb3511 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3948,10 +3948,10 @@ static void page_flip_completed(struct intel_crtc *intel_crtc)
drm_crtc_vblank_put(&intel_crtc->base);
wake_up_all(&dev_priv->pending_flip_queue);
- queue_work(dev_priv->wq, &work->work);
-
trace_i915_flip_complete(intel_crtc->plane,
work->pending_flip_obj);
+
+ queue_work(dev_priv->wq, &work->work);
}
void intel_crtc_wait_for_pending_flips(struct drm_crtc *crtc)