From 704890aaa1d5ba485f538cdf20b1030798253c87 Mon Sep 17 00:00:00 2001 From: Matthew Garrett Date: Sun, 9 Aug 2015 16:20:58 -0700 Subject: [PATCH 223/261] Rework linux16 command We want a single buffer that contains the entire kernel image in order to perform a TPM measurement. Allocate one and copy the entire kernel int it before pulling out the individual blocks later on. --- grub-core/loader/i386/pc/linux.c | 54 +++++++++++++++++++++++----------------- 1 file changed, 31 insertions(+), 23 deletions(-) diff --git a/grub-core/loader/i386/pc/linux.c b/grub-core/loader/i386/pc/linux.c index b19527e8e..60bb31fbf 100644 --- a/grub-core/loader/i386/pc/linux.c +++ b/grub-core/loader/i386/pc/linux.c @@ -124,13 +124,14 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)), grub_file_t file = 0; struct linux_kernel_header lh; grub_uint8_t setup_sects; - grub_size_t real_size; + grub_size_t real_size, kernel_offset = 0; grub_ssize_t len; int i; char *grub_linux_prot_chunk; int grub_linux_is_bzimage; grub_addr_t grub_linux_prot_target; grub_err_t err; + grub_uint8_t *kernel = NULL; grub_dl_ref (my_mod); @@ -144,7 +145,15 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)), if (! file) goto fail; - if (grub_file_read (file, &lh, sizeof (lh)) != sizeof (lh)) + len = grub_file_size (file); + kernel = grub_malloc (len); + if (!kernel) + { + grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("cannot allocate kernel buffer")); + goto fail; + } + + if (grub_file_read (file, kernel, len) != len) { if (!grub_errno) grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"), @@ -152,7 +161,10 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)), goto fail; } - if (lh.boot_flag != grub_cpu_to_le16 (0xaa55)) + grub_memcpy (&lh, kernel, sizeof (lh)); + kernel_offset = sizeof (lh); + + if (lh.boot_flag != grub_cpu_to_le16_compile_time (0xaa55)) { grub_error (GRUB_ERR_BAD_OS, "invalid magic number"); goto fail; @@ -170,7 +182,7 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)), maximal_cmdline_size = 256; - if (lh.header == grub_cpu_to_le32 (GRUB_LINUX_MAGIC_SIGNATURE) + if (lh.header == grub_cpu_to_le32_compile_time (GRUB_LINUX_MAGIC_SIGNATURE) && grub_le_to_cpu16 (lh.version) >= 0x0200) { grub_linux_is_bzimage = (lh.loadflags & GRUB_LINUX_FLAG_BIG_KERNEL); @@ -189,7 +201,7 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)), if (grub_le_to_cpu16 (lh.version) >= 0x0201) { - lh.heap_end_ptr = grub_cpu_to_le16 (GRUB_LINUX_HEAP_END_OFFSET); + lh.heap_end_ptr = grub_cpu_to_le32_compile_time (GRUB_LINUX_HEAP_END_OFFSET); lh.loadflags |= GRUB_LINUX_FLAG_CAN_USE_HEAP; } @@ -197,17 +209,17 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)), lh.cmd_line_ptr = grub_linux_real_target + GRUB_LINUX_CL_OFFSET; else { - lh.cl_magic = grub_cpu_to_le16 (GRUB_LINUX_CL_MAGIC); - lh.cl_offset = grub_cpu_to_le16 (GRUB_LINUX_CL_OFFSET); - lh.setup_move_size = grub_cpu_to_le16 (GRUB_LINUX_CL_OFFSET + lh.cl_magic = grub_cpu_to_le32_compile_time (GRUB_LINUX_CL_MAGIC); + lh.cl_offset = grub_cpu_to_le32_compile_time (GRUB_LINUX_CL_OFFSET); + lh.setup_move_size = grub_cpu_to_le32_compile_time (GRUB_LINUX_CL_OFFSET + maximal_cmdline_size); } } else { /* Your kernel is quite old... */ - lh.cl_magic = grub_cpu_to_le16 (GRUB_LINUX_CL_MAGIC); - lh.cl_offset = grub_cpu_to_le16 (GRUB_LINUX_CL_OFFSET); + lh.cl_magic = grub_cpu_to_le32_compile_time (GRUB_LINUX_CL_MAGIC); + lh.cl_offset = grub_cpu_to_le32_compile_time (GRUB_LINUX_CL_OFFSET); setup_sects = GRUB_LINUX_DEFAULT_SETUP_SECTS; @@ -312,15 +324,11 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)), grub_memmove (grub_linux_real_chunk, &lh, sizeof (lh)); len = real_size + GRUB_DISK_SECTOR_SIZE - sizeof (lh); - if (grub_file_read (file, grub_linux_real_chunk + sizeof (lh), len) != len) - { - if (!grub_errno) - grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"), - argv[0]); - goto fail; - } + grub_memcpy (grub_linux_real_chunk + sizeof (lh), kernel + kernel_offset, + len); + kernel_offset += len; - if (lh.header != grub_cpu_to_le32 (GRUB_LINUX_MAGIC_SIGNATURE) + if (lh.header != grub_cpu_to_le32_compile_time (GRUB_LINUX_MAGIC_SIGNATURE) || grub_le_to_cpu16 (lh.version) < 0x0200) /* Clear the heap space. */ grub_memset (grub_linux_real_chunk @@ -353,10 +361,8 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)), } len = grub_linux16_prot_size; - if (grub_file_read (file, grub_linux_prot_chunk, grub_linux16_prot_size) - != (grub_ssize_t) grub_linux16_prot_size && !grub_errno) - grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"), - argv[0]); + grub_memcpy (grub_linux_prot_chunk, kernel + kernel_offset, len); + kernel_offset += len; if (grub_errno == GRUB_ERR_NONE) { @@ -366,6 +372,8 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)), fail: + grub_free (kernel); + if (file) grub_file_close (file); @@ -405,7 +413,7 @@ grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)), lh = (struct linux_kernel_header *) grub_linux_real_chunk; - if (!(lh->header == grub_cpu_to_le32 (GRUB_LINUX_MAGIC_SIGNATURE) + if (!(lh->header == grub_cpu_to_le32_compile_time (GRUB_LINUX_MAGIC_SIGNATURE) && grub_le_to_cpu16 (lh->version) >= 0x0200)) { grub_error (GRUB_ERR_BAD_OS, "the kernel is too old for initrd"); -- 2.13.5