vbutil_kernel: copy zeropage fully

When copying the vmlinuz zeropage, the entries were being truncated even
though the boot protocol version was being retained. This means that
booting a kernel that depended on details from the zeropage's ignored
areas would find invalid information. Fix this by copying out the entire
possible range of memory.

BUG=chromium:230212
TEST=kernels can boot with CONFIG_RELOCATABLE
BRANCH=None

Change-Id: Ifb94bedcf881e17ab20fff44d8c1c1885b15ef9e
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/47832
Reviewed-by: Luigi Semenzato <semenzato@chromium.org>
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
This commit is contained in:
Kees Cook
2013-04-10 18:05:51 -07:00
committed by ChromeBot
parent 339b0ac9a0
commit e0e4ed404b
2 changed files with 16 additions and 14 deletions

View File

@@ -23,14 +23,6 @@
// RAM address where the 32-bit kernel expects to be started
#define CROS_32BIT_ENTRY_ADDR 0x100000
// Simplified version of the vmlinuz file header
struct linux_kernel_header
{
uint8_t pad0[0x01f1 - 0x0];
uint8_t setup_sects; // 1f1
uint8_t pad1[0x0230 - 0x1f2];
} __attribute__ ((packed));
// Simplified version of x86 kernel e820 memory map entries
#define E820_ENTRY_MAX 128
#define E820_TYPE_RAM 1
@@ -51,14 +43,21 @@ struct linux_kernel_params
uint8_t setup_sects; // 1f1
uint8_t pad2[0x1fe - 0x1f2];
uint16_t boot_flag; // 1fe
uint8_t pad3[0x210 - 0x200];
uint16_t jump; // 200
uint32_t header; // 202
uint16_t version; // 206
uint8_t pad3[0x210 - 0x208];
uint8_t type_of_loader; // 210
uint8_t pad4[0x218 - 0x211];
uint32_t ramdisk_image; // 218
uint32_t ramdisk_size; // 21c
uint8_t pad5[0x228 - 0x220];
uint32_t cmd_line_ptr; // 228
uint8_t pad6[0x2d0 - 0x22c];
uint32_t ramdisk_max; // 22c
uint32_t kernel_alignment; // 230
uint8_t relocatable_kernel; // 234
uint8_t min_alignment; // 235
uint8_t pad6[0x2d0 - 0x236];
struct linux_kernel_e820entry e820_entries[E820_ENTRY_MAX]; // 2d0 - cd0
} __attribute__ ((packed));

View File

@@ -271,8 +271,7 @@ static int ImportVmlinuzFile(const char *vmlinuz_file, arch_t arch,
uint64_t kernel_size;
uint64_t kernel32_start = 0;
uint64_t kernel32_size = 0;
struct linux_kernel_header* lh = 0;
struct linux_kernel_params* params = 0;
struct linux_kernel_params *params = NULL, *lh = NULL;
/* Read the kernel */
Debug("Reading %s\n", vmlinuz_file);
@@ -298,7 +297,7 @@ static int ImportVmlinuzFile(const char *vmlinuz_file, arch_t arch,
/* The first part of the x86 vmlinuz is a header, followed by a real-mode
* boot stub. We only want the 32-bit part. */
lh = (struct linux_kernel_header *)kernel_buf;
lh = (struct linux_kernel_params *)kernel_buf;
kernel32_start = (lh->setup_sects + 1) << 9;
if (kernel32_start >= kernel_size)
Fatal("Malformed kernel\n");
@@ -318,7 +317,8 @@ static int ImportVmlinuzFile(const char *vmlinuz_file, arch_t arch,
* tweak a few fields for our purposes */
params = (struct linux_kernel_params *)(g_param_data);
Memcpy(&(params->setup_sects), &(lh->setup_sects),
sizeof(*lh) - offsetof(struct linux_kernel_header, setup_sects));
offsetof(struct linux_kernel_params, e820_entries)
- offsetof(struct linux_kernel_params, setup_sects));
params->boot_flag = 0;
params->ramdisk_image = 0; /* we don't support initrd */
params->ramdisk_size = 0;
@@ -329,6 +329,9 @@ static int ImportVmlinuzFile(const char *vmlinuz_file, arch_t arch,
roundup(kernel32_size, CROS_ALIGN) +
find_cmdline_start((char *)g_config_data, g_config_size);
Debug(" cmdline_addr=0x%x\n", params->cmd_line_ptr);
Debug(" version=0x%x\n", params->version);
Debug(" kernel_alignment=0x%x\n", params->kernel_alignment);
Debug(" relocatable_kernel=0x%x\n", params->relocatable_kernel);
/* A fake e820 memory map with 2 entries */
params->n_e820_entry = 2;
params->e820_entries[0].start_addr = 0x00000000;