From 9305ede6afe2998b391cd225e02a18f37d62028e Mon Sep 17 00:00:00 2001
From: Jerome Glisse <jglisse@redhat.com>
Date: Wed, 9 Jan 2013 16:40:42 -0500
Subject: radeon/kms: fix dma relocation checking

We were checking the index against the size of the relocation buffer
instead of against the last index. This fix kernel segfault when
userspace submit ill formated command stream/relocation buffer pair.

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/radeon/r600_cs.c b/drivers/gpu/drm/radeon/r600_cs.c
index 6858a40..69ec24a 100644
--- a/drivers/gpu/drm/radeon/r600_cs.c
+++ b/drivers/gpu/drm/radeon/r600_cs.c
@@ -2563,16 +2563,16 @@ int r600_dma_cs_next_reloc(struct radeon_cs_parser *p,
 	struct radeon_cs_chunk *relocs_chunk;
 	unsigned idx;
 
+	*cs_reloc = NULL;
 	if (p->chunk_relocs_idx == -1) {
 		DRM_ERROR("No relocation chunk !\n");
 		return -EINVAL;
 	}
-	*cs_reloc = NULL;
 	relocs_chunk = &p->chunks[p->chunk_relocs_idx];
 	idx = p->dma_reloc_idx;
-	if (idx >= relocs_chunk->length_dw) {
+	if (idx >= p->nrelocs) {
 		DRM_ERROR("Relocs at %d after relocations chunk end %d !\n",
-			  idx, relocs_chunk->length_dw);
+			  idx, p->nrelocs);
 		return -EINVAL;
 	}
 	*cs_reloc = p->relocs_ptr[idx];
-- 
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