x86, microcode, AMD: Extend ucode size verification

Upstream commit: 44d60c0f5c58c2168f31df9a481761451840eb54

The different families have a different max size for the ucode patch,
adjust size checking to the family we're running on. Also, do not
vzalloc the max size of the ucode but only the actual size that is
passed on from the firmware loader.

Cc: <stable@kernel.org>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

diff --git a/arch/x86/kernel/microcode_amd.c b/arch/x86/kernel/microcode_amd.c
index e1af7c055c7d0c86c7e3a1fe789e597825185892..67381a227d672276f42062336af02f226adf4036 100644 (file)
--- a/arch/x86/kernel/microcode_amd.c
+++ b/arch/x86/kernel/microcode_amd.c
@@ -66,7 +66,6 @@ struct microcode_amd {
        unsigned int                    mpb[0];
 };
 
-#define UCODE_MAX_SIZE                 2048
 #define UCODE_CONTAINER_SECTION_HDR    8
 #define UCODE_CONTAINER_HEADER_SIZE    12
 
@@ -125,6 +124,37 @@ static int get_matching_microcode(int cpu, void *mc, int rev)
        return 1;
 }
 
+static unsigned int verify_ucode_size(int cpu, const u8 *buf, unsigned int size)
+{
+       struct cpuinfo_x86 *c = &cpu_data(cpu);
+       unsigned int max_size, actual_size;
+
+#define F1XH_MPB_MAX_SIZE 2048
+#define F14H_MPB_MAX_SIZE 1824
+#define F15H_MPB_MAX_SIZE 4096
+
+       switch (c->x86) {
+       case 0x14:
+               max_size = F14H_MPB_MAX_SIZE;
+               break;
+       case 0x15:
+               max_size = F15H_MPB_MAX_SIZE;
+               break;
+       default:
+               max_size = F1XH_MPB_MAX_SIZE;
+               break;
+       }
+
+       actual_size = buf[4] + (buf[5] << 8);
+
+       if (actual_size > size || actual_size > max_size) {
+               pr_err("section size mismatch\n");
+               return 0;
+       }
+
+       return actual_size;
+}
+
 static int apply_microcode_amd(int cpu)
 {
        u32 rev, dummy;
@@ -162,11 +192,11 @@ static int get_ucode_data(void *to, const u8 *from, size_t n)
 }
 
 static void *
-get_next_ucode(const u8 *buf, unsigned int size, unsigned int *mc_size)
+get_next_ucode(int cpu, const u8 *buf, unsigned int size, unsigned int *mc_size)
 {
-       unsigned int total_size;
+       unsigned int actual_size = 0;
        u8 section_hdr[UCODE_CONTAINER_SECTION_HDR];
-       void *mc;
+       void *mc = NULL;
 
        if (get_ucode_data(section_hdr, buf, UCODE_CONTAINER_SECTION_HDR))
                return NULL;
@@ -176,23 +206,18 @@ get_next_ucode(const u8 *buf, unsigned int size, unsigned int *mc_size)
                return NULL;
        }
 
-       total_size = (unsigned long) (section_hdr[4] + (section_hdr[5] << 8));
-
-       if (total_size > size || total_size > UCODE_MAX_SIZE) {
-               pr_err("error: size mismatch\n");
+       actual_size = verify_ucode_size(cpu, buf, size);
+       if (!actual_size)
                return NULL;
-       }
 
-       mc = vmalloc(UCODE_MAX_SIZE);
-       if (mc) {
-               memset(mc, 0, UCODE_MAX_SIZE);
-               if (get_ucode_data(mc, buf + UCODE_CONTAINER_SECTION_HDR,
-                                  total_size)) {
-                       vfree(mc);
-                       mc = NULL;
-               } else
-                       *mc_size = total_size + UCODE_CONTAINER_SECTION_HDR;
-       }
+       mc = vmalloc(actual_size);
+       if (!mc)
+               return NULL;
+
+       memset(mc, 0, actual_size);
+       get_ucode_data(mc, buf + UCODE_CONTAINER_SECTION_HDR, actual_size);
+       *mc_size = actual_size + UCODE_CONTAINER_SECTION_HDR;
+       
        return mc;
 }
 
@@ -258,7 +283,7 @@ generic_load_microcode(int cpu, const u8 *data, size_t size)
                unsigned int uninitialized_var(mc_size);
                struct microcode_header_amd *mc_header;
 
-               mc = get_next_ucode(ucode_ptr, leftover, &mc_size);
+               mc = get_next_ucode(cpu, ucode_ptr, leftover, &mc_size);
                if (!mc)
                        break;