While adding support loading kernel and initrd above 4G to grub2 in legacy mode, I was referring to efi_high_alloc(). That will allocate buffer for kernel and then initrd, and initrd will use kernel buffer start as limit. During testing found two buffers will be overlapped when initrd size is very big like 400M. It turns out efi_high_alloc() boundary checking is not right. end - size will be the new start, and should not compare new start with max, we need to make sure end is smaller than max. Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> --- drivers/firmware/efi/libstub/efi-stub-helper.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) Index: linux-2.6/drivers/firmware/efi/libstub/efi-stub-helper.c =================================================================== --- linux-2.6.orig/drivers/firmware/efi/libstub/efi-stub-helper.c +++ linux-2.6/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -183,12 +183,12 @@ again: start = desc->phys_addr; end = start + desc->num_pages * (1UL << EFI_PAGE_SHIFT); - if ((start + size) > end || (start + size) > max) - continue; - - if (end - size > max) + if (end > max) end = max; + if ((start + size) > end) + continue; + if (round_down(end - size, align) < start) continue; -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
