From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Matthew Garrett <mjg59@coreos.com>
Date: Thu, 13 Oct 2016 13:55:26 -0700
Subject: [PATCH] Make TPM errors less fatal
Handle TPM errors, and stop trying to use the TPM once we hit one.
---
grub-core/kern/dl.c | 1 +
grub-core/kern/i386/pc/tpm.c | 21 +++++++++++++++++----
grub-core/lib/cmdline.c | 1 +
grub-core/loader/i386/efi/linux.c | 2 ++
grub-core/loader/i386/linux.c | 1 +
grub-core/loader/i386/multiboot_mbi.c | 1 +
grub-core/loader/i386/pc/linux.c | 1 +
grub-core/loader/linux.c | 2 ++
grub-core/loader/multiboot.c | 1 +
grub-core/loader/multiboot_mbi2.c | 1 +
grub-core/script/execute.c | 1 +
11 files changed, 29 insertions(+), 4 deletions(-)
diff --git a/grub-core/kern/dl.c b/grub-core/kern/dl.c
index d0989573866..91105bc4677 100644
--- a/grub-core/kern/dl.c
+++ b/grub-core/kern/dl.c
@@ -831,6 +831,7 @@ grub_dl_load_file (const char *filename)
grub_file_close (file);
grub_tpm_measure(core, size, GRUB_BINARY_PCR, "grub_module", filename);
+ grub_print_error();
mod = grub_dl_load_core (core, size);
grub_free (core);
diff --git a/grub-core/kern/i386/pc/tpm.c b/grub-core/kern/i386/pc/tpm.c
index 8c6c1e6ece2..f6f264aff2e 100644
--- a/grub-core/kern/i386/pc/tpm.c
+++ b/grub-core/kern/i386/pc/tpm.c
@@ -7,21 +7,28 @@
#define TCPA_MAGIC 0x41504354
+static int tpm_presence = -1;
+
int tpm_present(void);
int tpm_present(void)
{
struct grub_bios_int_registers regs;
+ if (tpm_presence != -1)
+ return tpm_presence;
+
regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
regs.eax = 0xbb00;
regs.ebx = TCPA_MAGIC;
grub_bios_interrupt (0x1a, ®s);
if (regs.eax == 0)
- return 1;
+ tpm_presence = 1;
+ else
+ tpm_presence = 0;
- return 0;
+ return tpm_presence;
}
grub_err_t
@@ -49,7 +56,10 @@ grub_tpm_execute(PassThroughToTPM_InputParamBlock *inbuf,
grub_bios_interrupt (0x1a, ®s);
if (regs.eax)
- return grub_error (GRUB_ERR_IO, N_("TPM error %x\n"), regs.eax);
+ {
+ tpm_presence = 0;
+ return grub_error (GRUB_ERR_IO, N_("TPM error %x, disabling TPM"), regs.eax);
+ }
return 0;
}
@@ -126,7 +136,10 @@ grub_tpm_log_event(unsigned char *buf, grub_size_t size, grub_uint8_t pcr,
grub_free(event);
if (regs.eax)
- return grub_error (GRUB_ERR_IO, N_("TPM error %x\n"), regs.eax);
+ {
+ tpm_presence = 0;
+ return grub_error (GRUB_ERR_IO, N_("TPM error %x, disabling TPM"), regs.eax);
+ }
return 0;
}
diff --git a/grub-core/lib/cmdline.c b/grub-core/lib/cmdline.c
index 178f7382f07..d5c12957cad 100644
--- a/grub-core/lib/cmdline.c
+++ b/grub-core/lib/cmdline.c
@@ -128,6 +128,7 @@ int grub_create_loader_cmdline (int argc, char *argv[], char *buf,
grub_tpm_measure ((void *)orig, grub_strlen (orig), GRUB_ASCII_PCR,
"grub_kernel_cmdline", orig);
+ grub_print_error();
return i;
}
diff --git a/grub-core/loader/i386/efi/linux.c b/grub-core/loader/i386/efi/linux.c
index 074dbd6513e..ea9f5134e67 100644
--- a/grub-core/loader/i386/efi/linux.c
+++ b/grub-core/loader/i386/efi/linux.c
@@ -133,6 +133,7 @@ grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)),
goto fail;
}
grub_tpm_measure (ptr, cursize, GRUB_BINARY_PCR, "grub_linuxefi", "Initrd");
+ grub_print_error();
ptr += cursize;
grub_memset (ptr, 0, ALIGN_UP_OVERHEAD (cursize, 4));
ptr += ALIGN_UP_OVERHEAD (cursize, 4);
@@ -198,6 +199,7 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
}
grub_tpm_measure (kernel, filelen, GRUB_BINARY_PCR, "grub_linuxefi", "Kernel");
+ grub_print_error();
rc = grub_linuxefi_secure_validate (kernel, filelen);
if (rc < 0)
diff --git a/grub-core/loader/i386/linux.c b/grub-core/loader/i386/linux.c
index 273f48a6c88..76304f05700 100644
--- a/grub-core/loader/i386/linux.c
+++ b/grub-core/loader/i386/linux.c
@@ -726,6 +726,7 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
}
grub_tpm_measure (kernel, len, GRUB_BINARY_PCR, "grub_linux", "Kernel");
+ grub_print_error();
grub_memcpy (&lh, kernel, sizeof (lh));
diff --git a/grub-core/loader/i386/multiboot_mbi.c b/grub-core/loader/i386/multiboot_mbi.c
index 2ce424a997b..ca85358f771 100644
--- a/grub-core/loader/i386/multiboot_mbi.c
+++ b/grub-core/loader/i386/multiboot_mbi.c
@@ -175,6 +175,7 @@ grub_multiboot_load (grub_file_t file, const char *filename)
}
grub_tpm_measure((unsigned char*)buffer, len, GRUB_BINARY_PCR, "grub_multiboot", filename);
+ grub_print_error();
header = find_header (buffer, len);
diff --git a/grub-core/loader/i386/pc/linux.c b/grub-core/loader/i386/pc/linux.c
index 4f8c02288ec..cfff25c21b5 100644
--- a/grub-core/loader/i386/pc/linux.c
+++ b/grub-core/loader/i386/pc/linux.c
@@ -163,6 +163,7 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
}
grub_tpm_measure (kernel, len, GRUB_BINARY_PCR, "grub_linux16", "Kernel");
+ grub_print_error();
grub_memcpy (&lh, kernel, sizeof (lh));
kernel_offset = sizeof (lh);
diff --git a/grub-core/loader/linux.c b/grub-core/loader/linux.c
index 78c41e33416..c2c7cfcd0fd 100644
--- a/grub-core/loader/linux.c
+++ b/grub-core/loader/linux.c
@@ -290,6 +290,8 @@ grub_initrd_load (struct grub_linux_initrd_context *initrd_ctx,
return grub_errno;
}
grub_tpm_measure (ptr, cursize, GRUB_BINARY_PCR, "grub_initrd", "Initrd");
+ grub_print_error();
+
ptr += cursize;
}
if (newc)
diff --git a/grub-core/loader/multiboot.c b/grub-core/loader/multiboot.c
index 3b87dc4fab3..9a8dae5565b 100644
--- a/grub-core/loader/multiboot.c
+++ b/grub-core/loader/multiboot.c
@@ -442,6 +442,7 @@ grub_cmd_module (grub_command_t cmd __attribute__ ((unused)),
grub_file_close (file);
grub_tpm_measure (module, size, GRUB_BINARY_PCR, "grub_multiboot", argv[0]);
+ grub_print_error();
return GRUB_ERR_NONE;
}
diff --git a/grub-core/loader/multiboot_mbi2.c b/grub-core/loader/multiboot_mbi2.c
index 60ae4606fda..54078455e2f 100644
--- a/grub-core/loader/multiboot_mbi2.c
+++ b/grub-core/loader/multiboot_mbi2.c
@@ -133,6 +133,7 @@ grub_multiboot2_load (grub_file_t file, const char *filename)
COMPILE_TIME_ASSERT (MULTIBOOT_HEADER_ALIGN % 4 == 0);
grub_tpm_measure ((unsigned char *)mld.buffer, len, GRUB_BINARY_PCR, "grub_multiboot", filename);
+ grub_print_error();
header = find_header (mld.buffer, len);
if (header == 0)
diff --git a/grub-core/script/execute.c b/grub-core/script/execute.c
index 976643c47b0..93965777138 100644
--- a/grub-core/script/execute.c
+++ b/grub-core/script/execute.c
@@ -997,6 +997,7 @@ grub_script_execute_cmdline (struct grub_script_cmd *cmd)
cmdstring[cmdlen-1]= '\0';
grub_tpm_measure ((unsigned char *)cmdstring, cmdlen, GRUB_ASCII_PCR,
"grub_cmd", cmdstring);
+ grub_print_error();
grub_free(cmdstring);
invert = 0;
argc = argv.argc - 1;