futility/host lib: Fix coverity warnings

Assorted minor code issues, which we should fix so any new errors stand
out more.

BUG=chromium:643769
BRANCH=none
TEST=make runtests

Change-Id: Ib37b45dea54bd506b519b0304300b8d192e34339
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/382319
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>

7 files changed, 59 insertions, 45 deletions

diff --git a/host/arch/x86/lib/crossystem_arch.c b/host/arch/x86/lib/crossystem_arch.c
index d7e89fe1..2b5d00aa 100644
--- a/host/arch/x86/lib/crossystem_arch.c
+++ b/host/arch/x86/lib/crossystem_arch.c
@@ -170,9 +170,9 @@ int VbReadNvStorage(VbNvContext* vnc) {
 }
 
 
-int VbWriteNvStorage(VbNvContext* vnc) {
+int VbWriteNvStorage(VbNvContext* vnc)
+{
   unsigned offs, blksz;
-  VbSharedDataHeader *sh = VbSharedDataRead();
 
   if (!vnc->raw_changed)
     return 0;  /* Nothing changed, so no need to write */
@@ -189,8 +189,12 @@ int VbWriteNvStorage(VbNvContext* vnc) {
     return -1;
 
   /* Also attempt to write using mosys if using vboot2 */
-  if (sh && (sh->flags & VBSD_BOOT_FIRMWARE_VBOOT2))
-    VbWriteNvStorage_mosys(vnc);
+  VbSharedDataHeader *sh = VbSharedDataRead();
+  if (sh) {
+    if (sh->flags & VBSD_BOOT_FIRMWARE_VBOOT2)
+      VbWriteNvStorage_mosys(vnc);
+    free(sh);
+  }
 
   return 0;
 }
diff --git a/host/lib/crossystem.c b/host/lib/crossystem.c
index 87c74169..53ec6897 100644
--- a/host/lib/crossystem.c
+++ b/host/lib/crossystem.c
@@ -755,7 +755,7 @@ static int InAndroid() {
      check if file exists.  Using fstat because for some
      reason, stat() was seg faulting in Android */
   fd = open(MOSYS_ANDROID_PATH, O_RDONLY);
-  if (fstat(fd, &s) == 0) {
+  if (fd != -1 && fstat(fd, &s) == 0) {
     close(fd);
     return 1;
   }
diff --git a/host/lib/file_keys.c b/host/lib/file_keys.c
index fd07752b..a774ba22 100644
--- a/host/lib/file_keys.c
+++ b/host/lib/file_keys.c
@@ -22,45 +22,52 @@
 #include "host_common.h"
 #include "signature_digest.h"
 
-uint8_t* BufferFromFile(const char* input_file, uint64_t* len) {
-  int fd;
-  struct stat stat_fd;
-  uint8_t* buf = NULL;
+uint8_t *BufferFromFile(const char* input_file, uint64_t* len)
+{
+	int fd;
+	struct stat stat_fd;
+	uint8_t* buf = NULL;
 
-  if ((fd = open(input_file, O_RDONLY)) == -1) {
-    VBDEBUG(("Couldn't open file %s\n", input_file));
-    return NULL;
-  }
+	if ((fd = open(input_file, O_RDONLY)) == -1) {
+		VBDEBUG(("Couldn't open file %s\n", input_file));
+		return NULL;
+	}
 
-  if (-1 == fstat(fd, &stat_fd)) {
-    VBDEBUG(("Couldn't stat file %s\n", input_file));
-    return NULL;
-  }
-  *len = stat_fd.st_size;
+	if (-1 == fstat(fd, &stat_fd)) {
+		VBDEBUG(("Couldn't stat file %s\n", input_file));
+		close(fd);
+		return NULL;
+	}
+	*len = stat_fd.st_size;
 
-  buf = (uint8_t*)malloc(*len);
-  if (!buf) {
-    VbExError("Couldn't allocate %ld bytes for file %s\n", *len, input_file);
-    return NULL;
-  }
+	buf = (uint8_t *)malloc(*len);
+	if (!buf) {
+		VbExError("Couldn't allocate %ld bytes for file %s\n",
+			  *len, input_file);
+		close(fd);
+		return NULL;
+	}
 
-  if (*len != read(fd, buf, *len)) {
-    VBDEBUG(("Couldn't read file %s into a buffer\n", input_file));
-    return NULL;
-  }
+	if (*len != read(fd, buf, *len)) {
+		VBDEBUG(("Couldn't read file %s into a buffer\n", input_file));
+		free(buf);
+		close(fd);
+		return NULL;
+	}
 
-  close(fd);
-  return buf;
+	close(fd);
+	return buf;
 }
 
-RSAPublicKey* RSAPublicKeyFromFile(const char* input_file) {
-  uint64_t len;
-  RSAPublicKey* key = NULL;
-  uint8_t* buf = BufferFromFile(input_file, &len);
-  if (buf)
-    key = RSAPublicKeyFromBuf(buf, len);
-  free(buf);
-  return key;
+RSAPublicKey *RSAPublicKeyFromFile(const char *input_file) {
+	uint64_t len;
+	RSAPublicKey* key = NULL;
+
+	uint8_t *buf = BufferFromFile(input_file, &len);
+	if (buf)
+		key = RSAPublicKeyFromBuf(buf, len);
+	free(buf);
+	return key;
 }
 
 int DigestFile(char *input_file, enum vb2_hash_algorithm alg,
diff --git a/host/lib/host_keyblock.c b/host/lib/host_keyblock.c
index 21fa0995..dde8fe6c 100644
--- a/host/lib/host_keyblock.c
+++ b/host/lib/host_keyblock.c
@@ -92,6 +92,9 @@ struct vb2_keyblock *vb2_create_keyblock_external(
                 uint32_t flags,
                 const char *external_signer)
 {
+	if (!signing_key_pem_file || !data_key || !external_signer)
+		return NULL;
+
 	uint32_t signed_size = sizeof(struct vb2_keyblock) + data_key->key_size;
 	uint32_t sig_data_size = vb2_rsa_sig_size(algorithm);
 	uint32_t block_size =
@@ -101,8 +104,6 @@ struct vb2_keyblock *vb2_create_keyblock_external(
 	struct vb2_keyblock *h = (struct vb2_keyblock *)calloc(block_size, 1);
 	if (!h)
 		return NULL;
-	if (!signing_key_pem_file || !data_key || !external_signer)
-		return NULL;
 
 	uint8_t *data_key_dest = (uint8_t *)(h + 1);
 	uint8_t *block_chk_dest = data_key_dest + data_key->key_size;
diff --git a/host/lib/host_misc.c b/host/lib/host_misc.c
index 3fb9b24e..89a6c2f1 100644
--- a/host/lib/host_misc.c
+++ b/host/lib/host_misc.c
@@ -27,7 +27,7 @@ char* StrCopy(char* dest, const char* src, int dest_size) {
 uint8_t* ReadFile(const char* filename, uint64_t* sizeptr) {
   FILE* f;
   uint8_t* buf;
-  uint64_t size;
+  long size;
 
   f = fopen(filename, "rb");
   if (!f) {
@@ -37,6 +37,8 @@ uint8_t* ReadFile(const char* filename, uint64_t* sizeptr) {
 
   fseek(f, 0, SEEK_END);
   size = ftell(f);
+  if (size < 0)
+    return NULL;
   rewind(f);
 
   buf = malloc(size);
diff --git a/host/lib21/host_key.c b/host/lib21/host_key.c
index 4ef18d88..2ebd08a1 100644
--- a/host/lib21/host_key.c
+++ b/host/lib21/host_key.c
@@ -18,7 +18,7 @@
 #include "host_key2.h"
 #include "host_misc.h"
 
-struct vb2_text_vs_enum vb2_text_vs_sig[] = {
+const struct vb2_text_vs_enum vb2_text_vs_sig[] = {
 	{"RSA1024", VB2_SIG_RSA1024},
 	{"RSA2048", VB2_SIG_RSA2048},
 	{"RSA4096", VB2_SIG_RSA4096},
@@ -26,7 +26,7 @@ struct vb2_text_vs_enum vb2_text_vs_sig[] = {
 	{0, 0}
 };
 
-struct vb2_text_vs_enum vb2_text_vs_hash[] = {
+const struct vb2_text_vs_enum vb2_text_vs_hash[] = {
 	{"SHA1",   VB2_HASH_SHA1},
 	{"SHA256", VB2_HASH_SHA256},
 	{"SHA512", VB2_HASH_SHA512},
@@ -155,7 +155,7 @@ int vb21_private_key_read(struct vb2_private_key **key_ptr,
 			  const char *filename)
 {
 	uint32_t size = 0;
-	uint8_t *buf;
+	uint8_t *buf = NULL;
 	int rv;
 
 	*key_ptr = NULL;
diff --git a/host/lib21/include/host_key2.h b/host/lib21/include/host_key2.h
index 4681a5f4..5a2ec0ad 100644
--- a/host/lib21/include/host_key2.h
+++ b/host/lib21/include/host_key2.h
@@ -55,8 +55,8 @@ const struct vb2_text_vs_enum *vb2_lookup_by_name(
 	const struct vb2_text_vs_enum *table,
 	const char *name);
 
-extern struct vb2_text_vs_enum vb2_text_vs_sig[];
-extern struct vb2_text_vs_enum vb2_text_vs_hash[];
+extern const struct vb2_text_vs_enum vb2_text_vs_sig[];
+extern const struct vb2_text_vs_enum vb2_text_vs_hash[];
 
 /**
  * Return the name of a signature algorithm.