From: Andrew Jeddeloh <andrew.jedde...@coreos.com>
Previously the setup_header length was just assumed to be the size of the
linux_kernel_params struct. The linux x86 32-bit boot protocol says that
the size of the linux_i386_kernel_header is 0x202 + the byte value at 0x201
in the linux_i386_kernel_header. Calculate the size of the header, rather
than assume it is the size of the linux_kernel_params struct.
Additionally, add some required members to the linux_kernel_params
struct and align the content of linux_i386_kernel_header struct with
it. New members naming was taken directly from Linux kernel source.
linux_kernel_params and linux_i386_kernel_header structs require more
cleanup. However, this is not urgent, so, let's do this after release.
Just in case...
Signed-off-by: Andrew Jeddeloh <andrew.jedde...@coreos.com>
Signed-off-by: Daniel Kiper <daniel.ki...@oracle.com>
---
grub-core/loader/i386/linux.c | 16 +++++++++++++++-
include/grub/i386/linux.h | 14 ++++++++++++--
2 files changed, 27 insertions(+), 3 deletions(-)
diff --git a/grub-core/loader/i386/linux.c b/grub-core/loader/i386/linux.c
index b6015913b..73e15a90f 100644
--- a/grub-core/loader/i386/linux.c
+++ b/grub-core/loader/i386/linux.c
@@ -767,7 +767,21 @@ grub_cmd_linux (grub_command_t cmd __attribute__
((unused)),
linux_params.kernel_alignment = (1 << align);
linux_params.ps_mouse = linux_params.padding10 = 0;
- len = sizeof (linux_params) - sizeof (lh);
+ /*
+ * The Linux 32-bit boot protocol defines the setup header size
+ * to be 0x202 + the byte value at 0x201.
+ */
+ len = 0x202 + *((char *) &linux_params.jump + 1);
+
+ /* Verify the struct is big enough so we do not write past the end. */
+ if (len > (char *) &linux_params.edd_mbr_sig_buffer - (char *)
&linux_params) {
+ grub_error (GRUB_ERR_BAD_OS, "Linux setup header too big");
+ goto fail;
+ }
+
+ /* We've already read lh so there is no need to read it second time. */
+ len -= sizeof(lh);
+
if (grub_file_read (file, (char *) &linux_params + sizeof (lh), len) != len)
{
if (!grub_errno)
diff --git a/include/grub/i386/linux.h b/include/grub/i386/linux.h
index a96059311..ce30e7fb0 100644
--- a/include/grub/i386/linux.h
+++ b/include/grub/i386/linux.h
@@ -46,6 +46,9 @@
#define VIDEO_CAPABILITY_SKIP_QUIRKS (1 << 0)
#define VIDEO_CAPABILITY_64BIT_BASE (1 << 1) /* Frame buffer base is
64-bit. */
+/* Maximum number of MBR signatures to store. */
+#define EDD_MBR_SIG_MAX 16
+
#ifdef __x86_64__
#define GRUB_LINUX_EFI_SIGNATURE \
@@ -142,6 +145,7 @@ struct linux_i386_kernel_header
grub_uint64_t setup_data;
grub_uint64_t pref_address;
grub_uint32_t init_size;
+ grub_uint32_t handover_offset;
} GRUB_PACKED;
/* Boot parameters for Linux based on 2.6.12. This is used by the setup
@@ -273,6 +277,7 @@ struct linux_kernel_params
grub_uint8_t padding9[0x1f1 - 0x1e9];
+ /* Linux setup header copy - BEGIN. */
grub_uint8_t setup_sects; /* The size of the setup in sectors */
grub_uint16_t root_flags; /* If the root is mounted readonly */
grub_uint16_t syssize; /* obsolete */
@@ -311,9 +316,14 @@ struct linux_kernel_params
grub_uint32_t payload_offset;
grub_uint32_t payload_length;
grub_uint64_t setup_data;
- grub_uint8_t pad2[120]; /* 258 */
+ grub_uint64_t pref_address;
+ grub_uint32_t init_size;
+ grub_uint32_t handover_offset;
+ /* Linux setup header copy - END. */
+
+ grub_uint8_t _pad7[40];
+ grub_uint32_t edd_mbr_sig_buffer[EDD_MBR_SIG_MAX]; /* 290 */
struct grub_e820_mmap e820_map[(0x400 - 0x2d0) / 20]; /* 2d0 */
-
} GRUB_PACKED;
#endif /* ! ASM_FILE */
--
2.11.0
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