Re: [Intel-gfx] [PATCH] drm/i915: fix use-after-free in page_flip_completed()
On Thu, Jan 26, 2017 at 02:46:20PM +, Chris Wilson wrote:
> On Thu, Jan 26, 2017 at 05:32:11PM +0300, Andrey Ryabinin wrote:
> > 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
> > 8803dc010f90
> > 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
>
> That's old, and indeed does seem to be present from that commit and not
> exposed by something later.
>
> Cc: # v2.6.36+
> Reviewed-by: Chris Wilson
Applied, thanks for patch&review.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
Re: [PATCH] drm/i915: fix use-after-free in page_flip_completed()
On Thu, Jan 26, 2017 at 05:32:11PM +0300, Andrey Ryabinin wrote:
> 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
> 8803dc010f90
> 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
That's old, and indeed does seem to be present from that commit and not
exposed by something later.
Cc: # v2.6.36+
Reviewed-by: Chris Wilson
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
[PATCH] drm/i915: fix use-after-free in page_flip_completed()
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
8803dc010f90
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
---
drivers/gpu/drm/i915/intel_display.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_display.c
b/drivers/gpu/drm/i915/intel_display.c
index 8d702cf..f04a95cd 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4268,10 +4268,10 @@ 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->unpin_work);
-
trace_i915_flip_complete(intel_crtc->plane,
work->pending_flip_obj);
+
+ queue_work(dev_priv->wq, &work->unpin_work);
}
static int intel_crtc_wait_for_pending_flips(struct drm_crtc *crtc)
--
2.10.2
