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Commit a18d89ca authored by Marcin Slusarz's avatar Marcin Slusarz Committed by Ben Skeggs
Browse files

drm/nouveau: fix notifier memory corruption bug 



nouveau_bo_wr32 expects offset to be in words, but we pass value in bytes,
so after commit 73412c38 ("drm/nouveau: allocate
kernel's notifier object at end of block") we started to overwrite some memory
after notifier buffer object (previously m2mf_ntfy was always 0, so it didn't
matter it was a value in bytes).

Reported-by: default avatarDominik Brodowski <linux@dominikbrodowski.net>
Reported-by: default avatarNigel Cunningham <lkml@nigelcunningham.com.au>
Signed-off-by: default avatarMarcin Slusarz <marcin.slusarz@gmail.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Pekka Paalanen <pq@iki.fi>
Cc: stable@kernel.org    [2.6.38]
Signed-off-by: default avatarBen Skeggs <bskeggs@redhat.com>
parent 11dea1a2

drivers/gpu/drm/nouveau/nouveau_fbcon.c

+2 −2
Original line number Diff line number Diff line
@@ -181,13 +181,13 @@ nouveau_fbcon_sync(struct fb_info *info) 
		OUT_RING  (chan, 0);

	}



	nouveau_bo_wr32(chan->notifier_bo, chan->m2mf_ntfy + 3, 0xffffffff);

	nouveau_bo_wr32(chan->notifier_bo, chan->m2mf_ntfy/4 + 3, 0xffffffff);

	FIRE_RING(chan);

	mutex_unlock(&chan->mutex);



	ret = -EBUSY;

	for (i = 0; i < 100000; i++) {

		if (!nouveau_bo_rd32(chan->notifier_bo, chan->m2mf_ntfy + 3)) {

		if (!nouveau_bo_rd32(chan->notifier_bo, chan->m2mf_ntfy/4 + 3)) {

			ret = 0;

			break;

		}