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95 lines
2.4 KiB

Fix most obvious intel-microcode2ucode buffer overruns.
Index: microcode_ctl-2.1-19/intel-microcode2ucode.c
===================================================================
--- microcode_ctl-2.1-19.orig/intel-microcode2ucode.c 2018-08-20 04:32:26.803450076 +0200
+++ microcode_ctl-2.1-19/intel-microcode2ucode.c 2018-08-20 04:33:49.324661025 +0200
@@ -47,16 +47,25 @@
char c[0];
};
+#define MAX_MICROCODE 4000000
+
int main(int argc, char *argv[])
{
char *filename = "/lib/firmware/microcode.dat";
FILE *input, *f;
char line[LINE_MAX];
- char buf[4000000];
+ char *buf = NULL;
union mcbuf *mc;
size_t bufsize, count, start;
int rc = EXIT_SUCCESS;
+ buf = malloc(MAX_MICROCODE);
+ if (!buf) {
+ printf("can't allocate buffer\n");
+ rc = EXIT_FAILURE;
+ goto out;
+ }
+
if (argv[1] != NULL)
filename = argv[1];
@@ -74,6 +83,12 @@
count = 0;
mc = (union mcbuf *) buf;
while (fgets(line, sizeof(line), input) != NULL) {
+ if ((count + 3) >= (MAX_MICROCODE / sizeof(mc->i[0]))) {
+ printf("input file is too big");
+ rc = EXIT_FAILURE;
+ goto out;
+ }
+
if (sscanf(line, "%x, %x, %x, %x",
&mc->i[count],
&mc->i[count + 1],
@@ -102,6 +117,10 @@
unsigned int family, model, stepping;
unsigned int year, month, day;
+ if ((start > bufsize) ||
+ ((bufsize - start) < sizeof(struct microcode_header_intel)))
+ goto out;
+
mc = (union mcbuf *) &buf[start];
if (mc->hdr.totalsize)
@@ -109,8 +128,12 @@
else
size = 2000 + sizeof(struct microcode_header_intel);
+ if (size > (bufsize - start))
+ goto out;
+
if (mc->hdr.ldrver != 1 || mc->hdr.hdrver != 1) {
- printf("unknown version/format:\n");
+ printf("unknown version/format: %d/%d\n",
+ mc->hdr.ldrver, mc->hdr.hdrver);
rc = EXIT_FAILURE;
break;
}
@@ -135,7 +158,11 @@
month = mc->hdr.date >> 24;
day = (mc->hdr.date >> 16) & 0xff;
- asprintf(&filename, "intel-ucode/%02x-%02x-%02x", family, model, stepping);
+ if (asprintf(&filename, "intel-ucode/%02x-%02x-%02x", family,
+ model, stepping) == -1) {
+ printf("Failed to generate ucode filename\n");
+ goto out;
+ }
printf("\n");
printf("%s\n", filename);
printf("signature: 0x%02x\n", mc->hdr.sig);
@@ -164,6 +191,11 @@
}
printf("\n");
+ if (start != bufsize)
+ printf("Finished parsing at byte %zu of %zu\n", start, bufsize);
+
out:
+ free(buf);
+
return rc;
}