[PATCH] ima-evm-utils: Prevent crash if pcr is invalid

[Frank Sorenson <sorenson@xxxxxxxxxx>]

If the pcr is invalid, evmctl will crash while accessing
an invalid memory address.  Verify the pcr is in the
expected range.

Also, correct range of an existing check.

Signed-off-by: Frank Sorenson <sorenson@xxxxxxxxxx>
---
 src/evmctl.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/evmctl.c b/src/evmctl.c
index 1815f55..a14337a 100644
--- a/src/evmctl.c
+++ b/src/evmctl.c
@@ -1975,6 +1975,11 @@ static int ima_measurement(const char *file)
 		tpmbanks = 0;
 
 	while (fread(&entry.header, sizeof(entry.header), 1, fp)) {
+		if (entry.header.pcr >= NUM_PCRS) {
+			log_err("Invalid PCR %d.\n", entry.header.pcr);
+			fclose(fp);
+			exit(1);
+		}
 		if (entry.header.name_len > TCG_EVENT_NAME_LEN_MAX) {
 			log_err("%d ERROR: event name too long!\n",
 				entry.header.name_len);
@@ -2180,7 +2185,7 @@ static int read_binary_bios_measurements(char *file, struct tpm_bank_info *bank)
 			log_info("%02u ", event.header.pcr);
 			log_dump(event.header.digest, SHA_DIGEST_LENGTH);
 		}
-		if (event.header.pcr > NUM_PCRS) {
+		if (event.header.pcr >= NUM_PCRS) {
 			log_err("Invalid PCR %d.\n", event.header.pcr);
 			err = 1;
 			break;
-- 
2.29.2