From: Nick Lopez github@glowingmonkey.org

stable inclusion from stable-v4.19.228 commit b2a21669ee98aafc41c6d42ef15af4dab9e6e882 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA72KO CVE: CVE-2022-48732

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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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 Signed-off-by: Yuan Can yuancan@huawei.com --- drivers/gpu/drm/nouveau/nvkm/subdev/bios/base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/base.c index f3c30b2a788e..8bff14ae16b0 100644 --- 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, 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; }