From e9524fb97ab5b41b85e1d3408f8e513433798f3c Mon Sep 17 00:00:00 2001 From: Arvind Sankar Date: Wed, 27 May 2020 19:26:02 -0400 Subject: [PATCH] efi/x86: Don't blow away existing initrd Commit 987053a30016 ("efi/x86: Move command-line initrd loading to efi_main") moved the command-line initrd loading into efi_main(), with a check to ensure that it was attempted only if the EFI stub was booted via efi_pe_entry rather than the EFI handover entry. However, in the case where it was booted via handover entry, and thus an initrd may have already been loaded by the bootloader, it then wrote 0 for the initrd address and size, removing any existing initrd. Fix this by checking if size is positive before setting the fields in the bootparams structure. Fixes: 987053a30016 ("efi/x86: Move command-line initrd loading to efi_main") Reported-by: Dan Williams Signed-off-by: Arvind Sankar Signed-off-by: Borislav Petkov Reviewed-by: Ard Biesheuvel Tested-by: Dan Williams Link: https://lkml.kernel.org/r/20200527232602.21596-1-nivedita@alum.mit.edu --- drivers/firmware/efi/libstub/x86-stub.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c index 99a0cfb0c7ad3..5a48d996ed710 100644 --- a/drivers/firmware/efi/libstub/x86-stub.c +++ b/drivers/firmware/efi/libstub/x86-stub.c @@ -768,10 +768,12 @@ unsigned long efi_main(efi_handle_t handle, efi_err("Failed to load initrd!\n"); goto fail; } - efi_set_u64_split(addr, &hdr->ramdisk_image, - &boot_params->ext_ramdisk_image); - efi_set_u64_split(size, &hdr->ramdisk_size, - &boot_params->ext_ramdisk_size); + if (size > 0) { + efi_set_u64_split(addr, &hdr->ramdisk_image, + &boot_params->ext_ramdisk_image); + efi_set_u64_split(size, &hdr->ramdisk_size, + &boot_params->ext_ramdisk_size); + } } /*