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x86/microcode/intel: Reuse microcode_sanity_check()

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IFS test image carries the same microcode header as regular Intel
microcode blobs.

Reuse microcode_sanity_check() in the IFS driver to perform sanity check
of the IFS test images too.

Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20221117035935.4136738-8-jithu.joseph@intel.com
This commit is contained in:
Jithu Joseph 2022-11-16 19:59:26 -08:00 committed by Borislav Petkov
parent 2e13ab0158
commit 514ee839c6
3 changed files with 102 additions and 100 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/x86/include/asm/cpu.h
View File

@ -96,5 +96,6 @@ static inline bool intel_cpu_signatures_match(unsigned int s1, unsigned int p1,
extern u64 x86_read_arch_cap_msr(void);
int intel_find_matching_signature(void *mc, unsigned int csig, int cpf);
int intel_microcode_sanity_check(void *mc, bool print_err);
#endif /* _ASM_X86_CPU_H */

99
arch/x86/kernel/cpu/intel.c
View File

@ -244,6 +244,105 @@ int intel_find_matching_signature(void *mc, unsigned int csig, int cpf)
}
EXPORT_SYMBOL_GPL(intel_find_matching_signature);
int intel_microcode_sanity_check(void *mc, bool print_err)
{
unsigned long total_size, data_size, ext_table_size;
struct microcode_header_intel *mc_header = mc;
struct extended_sigtable *ext_header = NULL;
u32 sum, orig_sum, ext_sigcount = 0, i;
struct extended_signature *ext_sig;
total_size = get_totalsize(mc_header);
data_size = get_datasize(mc_header);
if (data_size + MC_HEADER_SIZE > total_size) {
if (print_err)
pr_err("Error: bad microcode data file size.\n");
return -EINVAL;
}
if (mc_header->ldrver != 1 || mc_header->hdrver != 1) {
if (print_err)
pr_err("Error: invalid/unknown microcode update format.\n");
return -EINVAL;
}
ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
if (ext_table_size) {
u32 ext_table_sum = 0;
u32 *ext_tablep;
if (ext_table_size < EXT_HEADER_SIZE ||
((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
if (print_err)
pr_err("Error: truncated extended signature table.\n");
return -EINVAL;
}
ext_header = mc + MC_HEADER_SIZE + data_size;
if (ext_table_size != exttable_size(ext_header)) {
if (print_err)
pr_err("Error: extended signature table size mismatch.\n");
return -EFAULT;
}
ext_sigcount = ext_header->count;
/*
* Check extended table checksum: the sum of all dwords that
* comprise a valid table must be 0.
*/
ext_tablep = (u32 *)ext_header;
i = ext_table_size / sizeof(u32);
while (i--)
ext_table_sum += ext_tablep[i];
if (ext_table_sum) {
if (print_err)
pr_warn("Bad extended signature table checksum, aborting.\n");
return -EINVAL;
}
}
/*
* Calculate the checksum of update data and header. The checksum of
* valid update data and header including the extended signature table
* must be 0.
*/
orig_sum = 0;
i = (MC_HEADER_SIZE + data_size) / sizeof(u32);
while (i--)
orig_sum += ((u32 *)mc)[i];
if (orig_sum) {
if (print_err)
pr_err("Bad microcode data checksum, aborting.\n");
return -EINVAL;
}
if (!ext_table_size)
return 0;
/*
* Check extended signature checksum: 0 => valid.
*/
for (i = 0; i < ext_sigcount; i++) {
ext_sig = (void *)ext_header + EXT_HEADER_SIZE +
EXT_SIGNATURE_SIZE * i;
sum = (mc_header->sig + mc_header->pf + mc_header->cksum) -
(ext_sig->sig + ext_sig->pf + ext_sig->cksum);
if (sum) {
if (print_err)
pr_err("Bad extended signature checksum, aborting.\n");
return -EINVAL;
}
}
return 0;
}
EXPORT_SYMBOL_GPL(intel_microcode_sanity_check);
static void early_init_intel(struct cpuinfo_x86 *c)
{
u64 misc_enable;

102
arch/x86/kernel/cpu/microcode/intel.c
View File

@ -135,104 +135,6 @@ static void save_microcode_patch(struct ucode_cpu_info *uci, void *data, unsigne
intel_ucode_patch = p->data;
}
static int microcode_sanity_check(void *mc, bool print_err)
{
unsigned long total_size, data_size, ext_table_size;
struct microcode_header_intel *mc_header = mc;
struct extended_sigtable *ext_header = NULL;
u32 sum, orig_sum, ext_sigcount = 0, i;
struct extended_signature *ext_sig;
total_size = get_totalsize(mc_header);
data_size = get_datasize(mc_header);
if (data_size + MC_HEADER_SIZE > total_size) {
if (print_err)
pr_err("Error: bad microcode data file size.\n");
return -EINVAL;
}
if (mc_header->ldrver != 1 || mc_header->hdrver != 1) {
if (print_err)
pr_err("Error: invalid/unknown microcode update format.\n");
return -EINVAL;
}
ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
if (ext_table_size) {
u32 ext_table_sum = 0;
u32 *ext_tablep;
if ((ext_table_size < EXT_HEADER_SIZE)
|| ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
if (print_err)
pr_err("Error: truncated extended signature table.\n");
return -EINVAL;
}
ext_header = mc + MC_HEADER_SIZE + data_size;
if (ext_table_size != exttable_size(ext_header)) {
if (print_err)
pr_err("Error: extended signature table size mismatch.\n");
return -EFAULT;
}
ext_sigcount = ext_header->count;
/*
* Check extended table checksum: the sum of all dwords that
* comprise a valid table must be 0.
*/
ext_tablep = (u32 *)ext_header;
i = ext_table_size / sizeof(u32);
while (i--)
ext_table_sum += ext_tablep[i];
if (ext_table_sum) {
if (print_err)
pr_warn("Bad extended signature table checksum, aborting.\n");
return -EINVAL;
}
}
/*
* Calculate the checksum of update data and header. The checksum of
* valid update data and header including the extended signature table
* must be 0.
*/
orig_sum = 0;
i = (MC_HEADER_SIZE + data_size) / sizeof(u32);
while (i--)
orig_sum += ((u32 *)mc)[i];
if (orig_sum) {
if (print_err)
pr_err("Bad microcode data checksum, aborting.\n");
return -EINVAL;
}
if (!ext_table_size)
return 0;
/*
* Check extended signature checksum: 0 => valid.
*/
for (i = 0; i < ext_sigcount; i++) {
ext_sig = (void *)ext_header + EXT_HEADER_SIZE +
EXT_SIGNATURE_SIZE * i;
sum = (mc_header->sig + mc_header->pf + mc_header->cksum) -
(ext_sig->sig + ext_sig->pf + ext_sig->cksum);
if (sum) {
if (print_err)
pr_err("Bad extended signature checksum, aborting.\n");
return -EINVAL;
}
}
return 0;
}
/*
* Get microcode matching with BSP's model. Only CPUs with the same model as
* BSP can stay in the platform.
@ -253,7 +155,7 @@ scan_microcode(void *data, size_t size, struct ucode_cpu_info *uci, bool save)
mc_size = get_totalsize(mc_header);
if (!mc_size ||
mc_size > size ||
microcode_sanity_check(data, false) < 0)
intel_microcode_sanity_check(data, false) < 0)
break;
size -= mc_size;
@ -792,7 +694,7 @@ static enum ucode_state generic_load_microcode(int cpu, struct iov_iter *iter)
memcpy(mc, &mc_header, sizeof(mc_header));
data = mc + sizeof(mc_header);
if (!copy_from_iter_full(data, data_size, iter) ||
microcode_sanity_check(mc, true) < 0) {
intel_microcode_sanity_check(mc, true) < 0) {
break;
}