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Re: xen: Fix parsing of XZ kernel.
From: |
Andrei Borzenkov |
Subject: |
Re: xen: Fix parsing of XZ kernel. |
Date: |
Tue, 7 Feb 2017 12:56:08 +0100 |
Отправлено с iPhone
> 7 февр. 2017 г., в 0:51, Vladimir 'phcoder' Serbinenko <address@hidden>
> написал(а):
>
> In case of xz, the uncompressed size is appended to xz data which confuses
> our xz decompressor. Trim it.
>
> Daniel, Andrei, Alexander, do you agree that this should go into 2.02?
> ---
> grub-core/loader/i386/xen_file.c | 30 ++++++++++++++++++++++++------
> 1 file changed, 24 insertions(+), 6 deletions(-)
>
> diff --git a/grub-core/loader/i386/xen_file.c
> b/grub-core/loader/i386/xen_file.c
> index 37f9ad8..eabaf8f 100644
> --- a/grub-core/loader/i386/xen_file.c
> +++ b/grub-core/loader/i386/xen_file.c
> @@ -26,6 +26,8 @@ grub_xen_file (grub_file_t file)
> grub_elf_t elf;
> struct linux_kernel_header lh;
> grub_file_t off_file;
> + grub_uint32_t payload_offset, payload_length;
> + grub_uint8_t magic[6];
>
> elf = grub_elf_file (file, file->name);
> if (elf)
> @@ -46,20 +48,36 @@ grub_xen_file (grub_file_t file)
> return NULL;
> }
>
> - if (lh.payload_length < 4)
> + payload_length = lh.payload_length;
> + payload_offset = (lh.setup_sects + 1) * 512
> + + lh.payload_offset;
> +
> + if (payload_length < sizeof (magic))
> {
> grub_error (GRUB_ERR_BAD_OS, "payload too short");
> return NULL;
> }
>
> grub_dprintf ("xen", "found bzimage payload 0x%llx-0x%llx\n",
> - (unsigned long long) (lh.setup_sects + 1) * 512
> - + lh.payload_offset,
> + (unsigned long long) payload_offset,
> (unsigned long long) lh.payload_length);
>
> - off_file = grub_file_offset_open (file, (lh.setup_sects + 1) * 512
> - + lh.payload_offset,
> - lh.payload_length);
> + grub_file_seek (file, payload_offset);
> +
> + if (grub_file_read (file, &magic, sizeof (magic)) != sizeof (magic))
> + {
> + if (!grub_errno)
> + grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"),
> + file->name);
> + goto fail;
> + }
> +
> + /* Kernel suffixes xz payload with their uncompressed size.
> + Trim it. */
> + if (grub_memcmp (magic, "\3757zXZ\0", 6) == 0)
s/6/sizeof (magic)/ and magic string should better be defined (do not we use it
already somewhere?)
ok otherwise
> + payload_length -= 4;
> + off_file = grub_file_offset_open (file, payload_offset,
> + payload_length);
> if (!off_file)
> goto fail;
>
> --
> 2.9.3
>
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