Messages in this thread | | | Date | Mon, 03 Feb 2014 15:28:51 -0500 | From | Boris Ostrovsky <> | Subject | Re: [PATCH -v2] x86, microcode, AMD: Sanity-check initrd image |
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On 02/03/2014 02:52 PM, Borislav Petkov wrote: > On Mon, Feb 03, 2014 at 02:37:34PM -0500, Boris Ostrovsky wrote: >> It exploded when 'if (!container)' check was done *after* relocation, >> which made container non-zero. If you do the check *before* then I >> think you will catch the fact that container is empty. > Ah, right, this was it. > > Ok, just remove the signature check then and give it a try pls:
Yes, this fixes the bug. And it loads microcode for a good binary.
For these two patches: Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
(You might want to rename the final patch to something else since you are not checking the blob anymore).
Thanks.
-boris
> > -- > diff --git a/arch/x86/kernel/cpu/microcode/amd_early.c b/arch/x86/kernel/cpu/microcode/amd_early.c > index 41537ae7c31d..362994511be1 100644 > --- a/arch/x86/kernel/cpu/microcode/amd_early.c > +++ b/arch/x86/kernel/cpu/microcode/amd_early.c > @@ -37,12 +37,10 @@ static __initdata char ucode_path[] = "kernel/x86/microcode/AuthenticAMD.bin"; > > static struct cpio_data __init find_ucode_in_initrd(void) > { > - struct cpio_data ret; > long offset = 0; > char *path; > void *start; > size_t size; > - u32 *hdr; > > #ifdef CONFIG_X86_32 > struct boot_params *p; > @@ -60,21 +58,7 @@ static struct cpio_data __init find_ucode_in_initrd(void) > start = (void *)(boot_params.hdr.ramdisk_image + PAGE_OFFSET); > size = boot_params.hdr.ramdisk_size; > #endif > - > - ret = find_cpio_data(path, start, size, &offset); > - if (!ret.data) > - return ret; > - > - /* Verify we didn't get some garbage from the initrd. */ > - hdr = (u32 *)ret.data; > - > - if (hdr[0] != UCODE_MAGIC || > - hdr[1] != UCODE_EQUIV_CPU_TABLE_TYPE || > - hdr[2] == 0) { > - ret.data = NULL; > - ret.size = 0; > - } > - return ret; > + return find_cpio_data(path, start, size, &offset); > } > > static size_t compute_container_size(u8 *data, u32 total_size) > -- >
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