From: Nick Lopez github@glowingmonkey.org
commit 1b777d4d9e383d2744fc9b3a09af6ec1893c8b1a upstream.
Bounds checking when parsing init scripts embedded in the BIOS reject access to the last byte. This causes driver initialization to fail on Apple eMac's with GeForce 2 MX GPUs, leaving the system with no working console.
This is probably only seen on OpenFirmware machines like PowerPC Macs because the BIOS image provided by OF is only the used parts of the ROM, not a power-of-two blocks read from PCI directly so PCs always have empty bytes at the end that are never accessed.
Signed-off-by: Nick Lopez github@glowingmonkey.org Fixes: 4d4e9907ff572 ("drm/nouveau/bios: guard against out-of-bounds accesses to image") Cc: stable@vger.kernel.org # v4.10+ Reviewed-by: Ilia Mirkin imirkin@alum.mit.edu Reviewed-by: Karol Herbst kherbst@redhat.com Signed-off-by: Karol Herbst kherbst@redhat.com Link: https://patchwork.freedesktop.org/patch/msgid/20220122081906.2633061-1-githu... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/nouveau/nvkm/subdev/bios/base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/base.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/base.c @@ -38,7 +38,7 @@ nvbios_addr(struct nvkm_bios *bios, u32 *addr += bios->imaged_addr; }
- if (unlikely(*addr + size >= bios->size)) { + if (unlikely(*addr + size > bios->size)) { nvkm_error(&bios->subdev, "OOB %d %08x %08x\n", size, p, *addr); return false; }