Commit 1b777d4d authored by Nick Lopez's avatar Nick Lopez Committed by Karol Herbst

drm/nouveau: fix off by one in BIOS boundary checking

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: default avatarNick Lopez <github@glowingmonkey.org>
Fixes: 4d4e9907 ("drm/nouveau/bios: guard against out-of-bounds accesses to image")
Cc: <stable@vger.kernel.org> # v4.10+
Reviewed-by: default avatarIlia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: default avatarKarol Herbst <kherbst@redhat.com>
Signed-off-by: default avatarKarol Herbst <kherbst@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220122081906.2633061-1-github@glowingmonkey.org
parent 43f25179
......@@ -38,7 +38,7 @@ nvbios_addr(struct nvkm_bios *bios, u32 *addr, u8 size)
*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;
}
......
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