drm/nouveau/bios: guard against out-of-bounds accesses to image

[karo-tx-linux.git] / drivers / gpu / drm / nouveau / nvkm / subdev / bios / base.c

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/base.c
index e15b9627b07e12cacca0bb671813d9d9e3b58628..db5fa009a6194e0f091a7186c4b5fb02f8f5c7ce 100644 (file)
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/base.c
@@ -27,6 +27,40 @@
 #include <subdev/bios/bmp.h>
 #include <subdev/bios/bit.h>
 
+static bool
+nvbios_addr(struct nvkm_bios *bios, u32 *addr, u8 size)
+{
+       if (unlikely(*addr + size >= bios->size)) {
+               nvkm_error(&bios->subdev, "OOB %d %08x\n", size, *addr);
+               return false;
+       }
+       return true;
+}
+
+u8
+nvbios_rd08(struct nvkm_bios *bios, u32 addr)
+{
+       if (likely(nvbios_addr(bios, &addr, 1)))
+               return bios->data[addr];
+       return 0x00;
+}
+
+u16
+nvbios_rd16(struct nvkm_bios *bios, u32 addr)
+{
+       if (likely(nvbios_addr(bios, &addr, 2)))
+               return get_unaligned_le16(&bios->data[addr]);
+       return 0x0000;
+}
+
+u32
+nvbios_rd32(struct nvkm_bios *bios, u32 addr)
+{
+       if (likely(nvbios_addr(bios, &addr, 4)))
+               return get_unaligned_le32(&bios->data[addr]);
+       return 0x00000000;
+}
+
 u8
 nvbios_checksum(const u8 *data, int size)
 {