diff options
Diffstat (limited to 'arch/x86/kernel/cpu/microcode/amd.c')
| -rw-r--r-- | arch/x86/kernel/cpu/microcode/amd.c | 111 |
1 files changed, 109 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c index ad7da621091d..f5365b32582a 100644 --- a/arch/x86/kernel/cpu/microcode/amd.c +++ b/arch/x86/kernel/cpu/microcode/amd.c @@ -23,14 +23,18 @@ #include <linux/earlycpio.h> #include <linux/firmware.h> +#include <linux/bsearch.h> #include <linux/uaccess.h> #include <linux/vmalloc.h> #include <linux/initrd.h> #include <linux/kernel.h> #include <linux/pci.h> +#include <crypto/sha2.h> + #include <asm/microcode.h> #include <asm/processor.h> +#include <asm/cmdline.h> #include <asm/setup.h> #include <asm/cpu.h> #include <asm/msr.h> @@ -145,6 +149,98 @@ ucode_path[] __maybe_unused = "kernel/x86/microcode/AuthenticAMD.bin"; */ static u32 bsp_cpuid_1_eax __ro_after_init; +static bool sha_check = true; + +struct patch_digest { + u32 patch_id; + u8 sha256[SHA256_DIGEST_SIZE]; +}; + +#include "amd_shas.c" + +static int cmp_id(const void *key, const void *elem) +{ + struct patch_digest *pd = (struct patch_digest *)elem; + u32 patch_id = *(u32 *)key; + + if (patch_id == pd->patch_id) + return 0; + else if (patch_id < pd->patch_id) + return -1; + else + return 1; +} + +static bool need_sha_check(u32 cur_rev) +{ + switch (cur_rev >> 8) { + case 0x80012: return cur_rev <= 0x800126f; break; + case 0x83010: return cur_rev <= 0x830107c; break; + case 0x86001: return cur_rev <= 0x860010e; break; + case 0x86081: return cur_rev <= 0x8608108; break; + case 0x87010: return cur_rev <= 0x8701034; break; + case 0x8a000: return cur_rev <= 0x8a0000a; break; + case 0xa0011: return cur_rev <= 0xa0011da; break; + case 0xa0012: return cur_rev <= 0xa001243; break; + case 0xa1011: return cur_rev <= 0xa101153; break; + case 0xa1012: return cur_rev <= 0xa10124e; break; + case 0xa1081: return cur_rev <= 0xa108109; break; + case 0xa2010: return cur_rev <= 0xa20102f; break; + case 0xa2012: return cur_rev <= 0xa201212; break; + case 0xa6012: return cur_rev <= 0xa60120a; break; + case 0xa7041: return cur_rev <= 0xa704109; break; + case 0xa7052: return cur_rev <= 0xa705208; break; + case 0xa7080: return cur_rev <= 0xa708009; break; + case 0xa70c0: return cur_rev <= 0xa70C009; break; + case 0xaa002: return cur_rev <= 0xaa00218; break; + default: break; + } + + pr_info("You should not be seeing this. Please send the following couple of lines to x86-<at>-kernel.org\n"); + pr_info("CPUID(1).EAX: 0x%x, current revision: 0x%x\n", bsp_cpuid_1_eax, cur_rev); + return true; +} + +static bool verify_sha256_digest(u32 patch_id, u32 cur_rev, const u8 *data, unsigned int len) +{ + struct patch_digest *pd = NULL; + u8 digest[SHA256_DIGEST_SIZE]; + struct sha256_state s; + int i; + + if (x86_family(bsp_cpuid_1_eax) < 0x17 || + x86_family(bsp_cpuid_1_eax) > 0x19) + return true; + + if (!need_sha_check(cur_rev)) + return true; + + if (!sha_check) + return true; + + pd = bsearch(&patch_id, phashes, ARRAY_SIZE(phashes), sizeof(struct patch_digest), cmp_id); + if (!pd) { + pr_err("No sha256 digest for patch ID: 0x%x found\n", patch_id); + return false; + } + + sha256_init(&s); + sha256_update(&s, data, len); + sha256_final(&s, digest); + + if (memcmp(digest, pd->sha256, sizeof(digest))) { + pr_err("Patch 0x%x SHA256 digest mismatch!\n", patch_id); + + for (i = 0; i < SHA256_DIGEST_SIZE; i++) + pr_cont("0x%x ", digest[i]); + pr_info("\n"); + + return false; + } + + return true; +} + static u32 get_patch_level(void) { u32 rev, dummy __always_unused; @@ -497,6 +593,9 @@ static bool __apply_microcode_amd(struct microcode_amd *mc, u32 *cur_rev, { unsigned long p_addr = (unsigned long)&mc->hdr.data_code; + if (!verify_sha256_digest(mc->hdr.patch_id, *cur_rev, (const u8 *)p_addr, psize)) + return -1; + native_wrmsrl(MSR_AMD64_PATCH_LOADER, p_addr); if (x86_family(bsp_cpuid_1_eax) == 0x17) { @@ -572,8 +671,17 @@ void __init load_ucode_amd_bsp(struct early_load_data *ed, unsigned int cpuid_1_ struct cont_desc desc = { }; struct microcode_amd *mc; struct cpio_data cp = { }; + char buf[4]; u32 rev; + if (cmdline_find_option(boot_command_line, "microcode.amd_sha_check", buf, 4)) { + if (!strncmp(buf, "off", 3)) { + sha_check = false; + pr_warn_once("It is a very very bad idea to disable the blobs SHA check!\n"); + add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); + } + } + bsp_cpuid_1_eax = cpuid_1_eax; rev = get_patch_level(); @@ -903,8 +1011,7 @@ static int verify_and_add_patch(u8 family, u8 *fw, unsigned int leftover, } /* Scan the blob in @data and add microcode patches to the cache. */ -static enum ucode_state __load_microcode_amd(u8 family, const u8 *data, - size_t size) +static enum ucode_state __load_microcode_amd(u8 family, const u8 *data, size_t size) { u8 *fw = (u8 *)data; size_t offset; |