diff --git a/src/client/client_cli.c b/src/client/client_cli.c
index 891afeb..0ebc391 100644
--- a/src/client/client_cli.c
+++ b/src/client/client_cli.c
@@ -70,10 +70,14 @@ int main(int argc, char* argv[]) {
     save_to_disk = true;
   }
 
-  Config* config = config_create(str_dup(PROTOCOL_VERSION), NULL, NULL, save_to_disk, false, false,
-                                 false, false, 5, false, 0);
   int exit_code = 0;
   bool config_owned_by_pipeline = false;
+  Config* config = config_create(str_dup(PROTOCOL_VERSION), NULL, NULL, save_to_disk, false, false,
+                                 false, false, 5, false, 0);
+  if (config == NULL) {
+    exit_code = 1;
+    goto cleanup;
+  }
 
   int positional_args[2];
   int positional_count = 0;
diff --git a/src/client/scanner.c b/src/client/scanner.c
index 0f56f68..f4e48ad 100644
--- a/src/client/scanner.c
+++ b/src/client/scanner.c
@@ -91,7 +91,19 @@ DirectoryScanner* directory_scanner_create_full(char* root_directory, bool use_m
   scanner->max_size = max_size;
   scanner->min_size = min_size;
   scanner->follow_symlinks = follow_symlinks;
-  queue_enqueue(scanner->directories, str_dup(root_directory));
+  char* root_copy = str_dup(root_directory);
+  if (root_copy == NULL) {
+    for (int i = 0; i < scanner->include_count; i++)
+      free(scanner->include_patterns[i]);
+    free(scanner->include_patterns);
+    for (int i = 0; i < scanner->exclude_count; i++)
+      free(scanner->exclude_patterns[i]);
+    free(scanner->exclude_patterns);
+    queue_destroy(scanner->directories);
+    free(scanner);
+    return NULL;
+  }
+  queue_enqueue(scanner->directories, root_copy);
   return scanner;
 }
 
diff --git a/src/server/server.c b/src/server/server.c
index 9df4e92..141ecdc 100644
--- a/src/server/server.c
+++ b/src/server/server.c
@@ -247,10 +247,9 @@ int main(int argc, char* argv[]) {
     server_listen(g_server, handler);
   }
 
-  /* Graceful shutdown: if a signal requested cleanup, delete the server */
-  if (g_server_cleanup_requested) {
+  /* Graceful shutdown: delete the server */
+  if (g_server_cleanup_requested)
     log_message(LOG_LEVEL_INFO, "Shutdown requested, cleaning up");
-    server_delete(&g_server);
-  }
+  server_delete(&g_server);
   return 0;
 }
diff --git a/src/shared/config.c b/src/shared/config.c
index b9ff23c..e4654b3 100644
--- a/src/shared/config.c
+++ b/src/shared/config.c
@@ -82,6 +82,8 @@ void config_parse_ssh_dest(Config* config) {
 }
 
 void config_delete(Config* config) {
+  if (config == NULL)
+    return;
   free(config->version);
   free(config->send_directory);
   free(config->receive_root_directory);
@@ -260,10 +262,6 @@ Config* config_receive(int file_descriptor) {
                 MAX_PATTERN_COUNT);
     goto error;
   }
-  if ((size_t)ec > SIZE_MAX / sizeof(char*)) {
-    log_message(LOG_LEVEL_ERROR, "Exclude pattern count %d would cause integer overflow", ec);
-    goto error;
-  }
   config->exclude_count = ec;
   if (ec > 0) {
     config->exclude_patterns = malloc((size_t)ec * sizeof(char*));
@@ -293,10 +291,6 @@ Config* config_receive(int file_descriptor) {
                 MAX_PATTERN_COUNT);
     goto error;
   }
-  if ((size_t)ic > SIZE_MAX / sizeof(char*)) {
-    log_message(LOG_LEVEL_ERROR, "Include pattern count %d would cause integer overflow", ic);
-    goto error;
-  }
   config->include_count = ic;
   if (ic > 0) {
     config->include_patterns = malloc((size_t)ic * sizeof(char*));
@@ -340,6 +334,16 @@ error:
   free(config->version);
   free(config->send_directory);
   free(config->receive_root_directory);
+  for (int i = 0; i < config->exclude_count; i++)
+    free(config->exclude_patterns[i]);
+  free(config->exclude_patterns);
+  for (int i = 0; i < config->include_count; i++)
+    free(config->include_patterns[i]);
+  free(config->include_patterns);
+  free(config->tls_cert);
+  free(config->tls_key);
+  free(config->tls_ca);
+  free(config->ssh_destination);
   free(config->server_host);
   free(config);
   return NULL;
diff --git a/src/shared/file.c b/src/shared/file.c
index 7f41fe2..2d9f922 100644
--- a/src/shared/file.c
+++ b/src/shared/file.c
@@ -3,6 +3,7 @@
 #include <fcntl.h>
 #include <libgen.h>
 #include <stddef.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -109,6 +110,9 @@ bool file_load_data(File* file) {
   size_t bytes_read = file_content_to_buffer(file);
   if (bytes_read != file->data->size) {
     log_message(LOG_LEVEL_ERROR, "Did not read expected amount of bytes from file");
+    free(file->data->data);
+    file->data->data = NULL;
+    file->data->size = 0;
     return false;
   }
   return true;
@@ -140,11 +144,13 @@ static bool file_send_streaming(File* file, int file_descriptor) {
       if (ferror(fp)) {
         perror("Read error during streaming");
       }
+      send_status(file_descriptor, STATUS_ERROR);
       free(buf);
       fclose(fp);
       return false;
     }
     if (!send_n_data(file_descriptor, buf, nread)) {
+      send_status(file_descriptor, STATUS_ERROR);
       free(buf);
       fclose(fp);
       return false;
@@ -626,8 +632,13 @@ bool file_send_sendfile(File* file, int file_descriptor, bool use_metadata, int
 
   off_t offset = 0;
   while ((unsigned long long)offset < file_size) {
-    ssize_t sent = sendfile(file_descriptor, fd, &offset, file_size - offset);
+    size_t send_count = (size_t)(file_size - (unsigned long long)offset);
+    if ((unsigned long long)send_count != file_size - (unsigned long long)offset)
+      send_count = SIZE_MAX;
+    ssize_t sent = sendfile(file_descriptor, fd, &offset, send_count);
     if (sent == -1) {
+      if (errno == EINTR)
+        continue;
       perror("sendfile failed");
       close(fd);
       return false;
diff --git a/src/shared/log.c b/src/shared/log.c
index bc8ffed..bb7590a 100644
--- a/src/shared/log.c
+++ b/src/shared/log.c
@@ -16,6 +16,8 @@ void log_message(LogLevel log_level, const char* format, ...) {
   time_t now = time(NULL);
   struct tm result_buf;
   const struct tm* t = localtime_r(&now, &result_buf);
+  if (t == NULL)
+    return;
 
   fprintf(stderr, "%04d-%02d-%02d %02d:%02d:%02d [%s]: ", t->tm_year + 1900, t->tm_mon + 1,
           t->tm_mday, t->tm_hour, t->tm_min, t->tm_sec, log_level_strings[log_level]);
diff --git a/src/shared/metadata.h b/src/shared/metadata.h
index f15570f..28312f5 100644
--- a/src/shared/metadata.h
+++ b/src/shared/metadata.h
@@ -20,6 +20,9 @@
  * serialized as fixed-width integers.
  */
 
+/* Size of metadata fields on wire, excluding the int32_t `present` field that
+ * is always sent first. The total wire size for present metadata is
+ * sizeof(int32_t) + FILE_METADATA_WIRE_SIZE (32 bytes on most platforms). */
 #define FILE_METADATA_WIRE_SIZE (sizeof(int32_t) * 3 + sizeof(int64_t) * 2)
 
 void metadata_to_buf(char** buf, const FileMetadata* m);
diff --git a/src/shared/protocol.c b/src/shared/protocol.c
index 1e5cb7f..de99d55 100644
--- a/src/shared/protocol.c
+++ b/src/shared/protocol.c
@@ -10,7 +10,7 @@
 
 static __thread int io_read_fd = -1;
 static __thread int io_write_fd = -1;
-static SSL* io_ssl = NULL;
+static __thread SSL* io_ssl = NULL;
 
 static unsigned long long io_bwlimit = 0;
 static long long bw_tokens = 0;
diff --git a/src/shared/transport_ssh.c b/src/shared/transport_ssh.c
index 9b7950e..377fa63 100644
--- a/src/shared/transport_ssh.c
+++ b/src/shared/transport_ssh.c
@@ -119,10 +119,13 @@ Client* client_connect_ssh(const char* destination, int port) {
       close(sv[1]);
 
     char ssh_user[512];
+    int needed;
     if (r.user && r.user[0] != '\0')
-      snprintf(ssh_user, sizeof(ssh_user), "%s@%s", r.user, r.host);
+      needed = snprintf(ssh_user, sizeof(ssh_user), "%s@%s", r.user, r.host);
     else
-      snprintf(ssh_user, sizeof(ssh_user), "%s", r.host);
+      needed = snprintf(ssh_user, sizeof(ssh_user), "%s", r.host);
+    if ((size_t)needed >= sizeof(ssh_user))
+      fprintf(stderr, "Warning: ssh_user string truncated\n");
 
     size_t ssh_argv_max = 32;
     char** ssh_argv = calloc(ssh_argv_max, sizeof(char*));