Use _cleanup(free_and_erasep) where appropriate

Replaces #12959.

5 files changed, 34 insertions, 58 deletions

diff --git a/src/network/netdev/macsec.c b/src/network/netdev/macsec.c
index a4967e817b..cf281e75a6 100644
--- a/src/network/netdev/macsec.c
+++ b/src/network/netdev/macsec.c
@@ -718,7 +718,7 @@ int config_parse_macsec_key(
 
         _cleanup_(macsec_transmit_association_free_or_set_invalidp) TransmitAssociation *a = NULL;
         _cleanup_(macsec_receive_association_free_or_set_invalidp) ReceiveAssociation *b = NULL;
-        _cleanup_free_ void *p;
+        _cleanup_(erase_and_freep) void *p = NULL;
         MACsec *s = userdata;
         SecurityAssociation *dest;
         size_t l;
@@ -743,18 +743,17 @@ int config_parse_macsec_key(
 
         r = unhexmem_full(rvalue, strlen(rvalue), true, &p, &l);
         if (r < 0) {
-                log_syntax(unit, LOG_ERR, filename, line, r,
-                           "Failed to parse key. Ignoring assignment: %m");
+                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse key. Ignoring assignment: %m");
                 return 0;
         }
+
         if (l != 16) {
                 /* See DEFAULT_SAK_LEN in drivers/net/macsec.c */
-                explicit_bzero_safe(p, l);
-                log_syntax(unit, LOG_ERR, filename, line, 0,
-                           "Invalid key length (%zu). Ignoring assignment", l);
+                log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid key length (%zu). Ignoring assignment", l);
                 return 0;
         }
 
+        explicit_bzero_safe(dest->key, dest->key_len);
         free_and_replace(dest->key, p);
         dest->key_len = l;
 
@@ -972,7 +971,7 @@ int config_parse_macsec_use_for_encoding(
 }
 
 static int macsec_read_key_file(NetDev *netdev, SecurityAssociation *sa) {
-        _cleanup_free_ uint8_t *key = NULL;
+        _cleanup_(erase_and_freep) uint8_t *key = NULL;
         size_t key_len;
         int r;
 
@@ -987,12 +986,10 @@ static int macsec_read_key_file(NetDev *netdev, SecurityAssociation *sa) {
                 return log_netdev_error_errno(netdev, r,
                                               "Failed to read key from '%s', ignoring: %m",
                                               sa->key_file);
-        if (key_len != 16) {
-                explicit_bzero_safe(key, key_len);
+
+        if (key_len != 16)
                 return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
-                                              "Invalid key length (%zu bytes), ignoring: %m",
-                                              key_len);
-        }
+                                              "Invalid key length (%zu bytes), ignoring: %m", key_len);
 
         explicit_bzero_safe(sa->key, sa->key_len);
         free_and_replace(sa->key, key);
diff --git a/src/network/netdev/wireguard.c b/src/network/netdev/wireguard.c
index 154ca3b7a4..2e9651cceb 100644
--- a/src/network/netdev/wireguard.c
+++ b/src/network/netdev/wireguard.c
@@ -480,7 +480,7 @@ static int wireguard_decode_key_and_warn(
                 unsigned line,
                 const char *lvalue) {
 
-        _cleanup_free_ void *key = NULL;
+        _cleanup_(erase_and_freep) void *key = NULL;
         size_t len;
         int r;
 
@@ -501,12 +501,10 @@ static int wireguard_decode_key_and_warn(
         if (r < 0)
                 return log_syntax(unit, LOG_ERR, filename, line, r,
                            "Failed to decode wireguard key provided by %s=, ignoring assignment: %m", lvalue);
-        if (len != WG_KEY_LEN) {
-                explicit_bzero_safe(key, len);
+        if (len != WG_KEY_LEN)
                 return log_syntax(unit, LOG_ERR, filename, line, 0,
                            "Wireguard key provided by %s= has invalid length (%zu bytes), ignoring assignment.",
                            lvalue, len);
-        }
 
         memcpy(ret, key, WG_KEY_LEN);
         return 0;
@@ -894,7 +892,7 @@ static void wireguard_done(NetDev *netdev) {
 }
 
 static int wireguard_read_key_file(const char *filename, uint8_t dest[static WG_KEY_LEN]) {
-        _cleanup_free_ char *key = NULL;
+        _cleanup_(erase_and_freep) char *key = NULL;
         size_t key_len;
         int r;
 
@@ -905,17 +903,11 @@ static int wireguard_read_key_file(const char *filename, uint8_t dest[static WG_
         if (r < 0)
                 return r;
 
-        if (key_len != WG_KEY_LEN) {
-                r = -EINVAL;
-                goto finalize;
-        }
+        if (key_len != WG_KEY_LEN)
+                return -EINVAL;
 
         memcpy(dest, key, WG_KEY_LEN);
-        r = 0;
-
-finalize:
-        explicit_bzero_safe(key, key_len);
-        return r;
+        return 0;
 }
 
 static int wireguard_peer_verify(WireguardPeer *peer) {
diff --git a/src/reply-password/reply-password.c b/src/reply-password/reply-password.c
index f8f6c2d3ec..7fd1fc5d1d 100644
--- a/src/reply-password/reply-password.c
+++ b/src/reply-password/reply-password.c
@@ -35,7 +35,7 @@ static int send_on_socket(int fd, const char *socket_name, const void *packet, s
 }
 
 int main(int argc, char *argv[]) {
-        _cleanup_free_ char *packet = NULL;
+        _cleanup_(erase_and_freep) char *packet = NULL;
         _cleanup_close_ int fd = -1;
         size_t length = 0;
         int r;
@@ -93,7 +93,5 @@ int main(int argc, char *argv[]) {
         r = send_on_socket(fd, argv[2], packet, length);
 
 finish:
-        explicit_bzero_safe(packet, length);
-
         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 }
diff --git a/src/shared/ask-password-api.c b/src/shared/ask-password-api.c
index 6c0a369902..00c41a0382 100644
--- a/src/shared/ask-password-api.c
+++ b/src/shared/ask-password-api.c
@@ -63,13 +63,16 @@ static int lookup_key(const char *keyname, key_serial_t *ret) {
 }
 
 static int retrieve_key(key_serial_t serial, char ***ret) {
-        _cleanup_free_ char *p = NULL;
-        long m = 100, n;
+        size_t nfinal, m = 100;
         char **l;
+        _cleanup_(erase_and_freep) char *pfinal = NULL;
 
         assert(ret);
 
         for (;;) {
+                _cleanup_(erase_and_freep) char *p = NULL;
+                long n;
+
                 p = new(char, m);
                 if (!p)
                         return -ENOMEM;
@@ -77,33 +80,28 @@ static int retrieve_key(key_serial_t serial, char ***ret) {
                 n = keyctl(KEYCTL_READ, (unsigned long) serial, (unsigned long) p, (unsigned long) m, 0);
                 if (n < 0)
                         return -errno;
-                if (n < m)
+                if ((size_t) n < m) {
+                        nfinal = (size_t) n;
+                        pfinal = TAKE_PTR(p);
                         break;
-
-                explicit_bzero_safe(p, m);
+                }
 
                 if (m > LONG_MAX / 2) /* overflow check */
                         return -ENOMEM;
                 m *= 2;
-                if ((long) (size_t) m != m) /* make sure that this still fits if converted to size_t */
-                        return -ENOMEM;
-
-                free(p);
         }
 
-        l = strv_parse_nulstr(p, n);
+        l = strv_parse_nulstr(pfinal, nfinal);
         if (!l)
                 return -ENOMEM;
 
-        explicit_bzero_safe(p, n);
-
         *ret = l;
         return 0;
 }
 
 static int add_to_keyring(const char *keyname, AskPasswordFlags flags, char **passwords) {
         _cleanup_strv_free_erase_ char **l = NULL;
-        _cleanup_free_ char *p = NULL;
+        _cleanup_(erase_and_freep) char *p = NULL;
         key_serial_t serial;
         size_t n;
         int r;
@@ -131,7 +129,6 @@ static int add_to_keyring(const char *keyname, AskPasswordFlags flags, char **pa
                 return r;
 
         serial = add_key("user", keyname, p, n, KEY_SPEC_USER_KEYRING);
-        explicit_bzero_safe(p, n);
         if (serial == -1)
                 return -errno;
 
diff --git a/src/tty-ask-password-agent/tty-ask-password-agent.c b/src/tty-ask-password-agent/tty-ask-password-agent.c
index 271d0bb90c..843c302bf4 100644
--- a/src/tty-ask-password-agent/tty-ask-password-agent.c
+++ b/src/tty-ask-password-agent/tty-ask-password-agent.c
@@ -238,13 +238,13 @@ finish:
 }
 
 static int send_passwords(const char *socket_name, char **passwords) {
-        _cleanup_free_ char *packet = NULL;
+        _cleanup_(erase_and_freep) char *packet = NULL;
         _cleanup_close_ int socket_fd = -1;
         union sockaddr_union sa = {};
         size_t packet_length = 1;
         char **p, *d;
         ssize_t n;
-        int r, salen;
+        int salen;
 
         assert(socket_name);
 
@@ -266,22 +266,14 @@ static int send_passwords(const char *socket_name, char **passwords) {
                 d = stpcpy(d, *p) + 1;
 
         socket_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
-        if (socket_fd < 0) {
-                r = log_debug_errno(errno, "socket(): %m");
-                goto finish;
-        }
+        if (socket_fd < 0)
+                return log_debug_errno(errno, "socket(): %m");
 
         n = sendto(socket_fd, packet, packet_length, MSG_NOSIGNAL, &sa.sa, salen);
-        if (n < 0) {
-                r = log_debug_errno(errno, "sendto(): %m");
-                goto finish;
-        }
+        if (n < 0)
+                return log_debug_errno(errno, "sendto(): %m");
 
-        r = (int) n;
-
-finish:
-        explicit_bzero_safe(packet, packet_length);
-        return r;
+        return (int) n;
 }
 
 static int parse_password(const char *filename, char **wall) {