Convert more strcat and strcpy to strn variants

15 files changed, 81 insertions, 81 deletions

diff --git a/src/cli/stasis/args.c b/src/cli/stasis/args.c
index 696f3a6..98b4479 100644
--- a/src/cli/stasis/args.c
+++ b/src/cli/stasis/args.c
@@ -89,20 +89,20 @@ void usage(char *progname) {
         char opt_long[50] = {0};        // --? [ARG]?
         char opt_short[50] = {0};        // -? [ARG]?
 
-        strcat(opt_long, "--");
-        strcat(opt_long, long_options[x].name);
+        strncat(opt_long, "--", sizeof(opt_long) - strlen(opt_long) - 1);
+        strncat(opt_long, long_options[x].name, sizeof(opt_long) - strlen(opt_long) - 1);
         if (long_options[x].has_arg) {
-            strcat(opt_long, " ARG");
+            strncat(opt_long, " ARG", sizeof(opt_long) - strlen(opt_long) - 1);
         }
 
         if (long_options[x].val <= 'z') {
-            strcat(opt_short, "-");
+            strncat(opt_short, "-", sizeof(opt_short) - strlen(opt_short) - 1);
             opt_short[1] = (char) long_options[x].val;
             if (long_options[x].has_arg) {
-                strcat(opt_short, " ARG");
+                strncat(opt_short, " ARG", sizeof(opt_short) - strlen(opt_short) - 1);
             }
         } else {
-            strcat(opt_short, "  ");
+            strncat(opt_short, "  ", sizeof(opt_short) - strlen(opt_short) - 1);
         }
 
         const char *opt_fmt = "  %%-%ds\t%%s\t\t%%s";
diff --git a/src/cli/stasis/stasis_main.c b/src/cli/stasis/stasis_main.c
index 9b3c6ba..328d825 100644
--- a/src/cli/stasis/stasis_main.c
+++ b/src/cli/stasis/stasis_main.c
@@ -532,7 +532,7 @@ int main(int argc, char *argv[]) {
                 globals.continue_on_error = true;
                 break;
             case 'p':
-                strcpy(python_override_version, optarg);
+                strncpy(python_override_version, optarg, sizeof(python_override_version) - 1);
                 break;
             case 'l':
                 globals.cpu_limit = strtol(optarg, NULL, 10);
@@ -652,9 +652,9 @@ int main(int argc, char *argv[]) {
     configure_jfrog_cli(&ctx);
 
     runtime_apply(ctx.runtime.environ);
-    strcpy(env_name, ctx.info.release_name);
-    strcpy(env_name_testing, env_name);
-    strcat(env_name_testing, "-test");
+    strncpy(env_name, ctx.info.release_name, sizeof(env_name) - 1);
+    strncpy(env_name_testing, env_name, sizeof(env_name_testing) - 1);
+    strncat(env_name_testing, "-test", sizeof(env_name_testing) - strlen(env_name_testing) - 1);
     char *envs[] = {
         "release", env_name,
         "testing", env_name_testing,
diff --git a/src/cli/stasis_indexer/helpers.c b/src/cli/stasis_indexer/helpers.c
index 6dc653d..27608d3 100644
--- a/src/cli/stasis_indexer/helpers.c
+++ b/src/cli/stasis_indexer/helpers.c
@@ -96,44 +96,44 @@ int pandoc_exec(const char *in_file, const char *out_file, const char *css_file,
     if (!get_pandoc_version(&pandoc_version)) {
         // < 2.19
         if (pandoc_version < 0x02130000) {
-            strcat(pandoc_versioned_args, "--self-contained ");
+            strncat(pandoc_versioned_args, "--self-contained ", sizeof(pandoc_versioned_args) - strlen(pandoc_versioned_args) - 1);
         } else {
             // >= 2.19
-            strcat(pandoc_versioned_args, "--embed-resources ");
+            strncat(pandoc_versioned_args, "--embed-resources ", sizeof(pandoc_versioned_args) - strlen(pandoc_versioned_args) - 1);
         }
 
         // >= 1.15.0.4
         if (pandoc_version >= 0x010f0004) {
-            strcat(pandoc_versioned_args, "--standalone ");
+            strncat(pandoc_versioned_args, "--standalone ", sizeof(pandoc_versioned_args) - strlen(pandoc_versioned_args) - 1);
         }
 
         // >= 1.10.0.1
         if (pandoc_version >= 0x010a0001) {
-            strcat(pandoc_versioned_args, "-f gfm+autolink_bare_uris ");
+            strncat(pandoc_versioned_args, "-f gfm+autolink_bare_uris ", sizeof(pandoc_versioned_args) - strlen(pandoc_versioned_args) - 1);
         }
 
         // > 3.1.9
         if (pandoc_version > 0x03010900) {
-            strcat(pandoc_versioned_args, "-f gfm+alerts ");
+            strncat(pandoc_versioned_args, "-f gfm+alerts ", sizeof(pandoc_versioned_args) - strlen(pandoc_versioned_args) - 1);
         }
     }
 
     // Converts a markdown file to html
     char cmd[STASIS_BUFSIZ] = {0};
-    strcpy(cmd, "pandoc ");
-    strcat(cmd, pandoc_versioned_args);
+    strncpy(cmd, "pandoc ", sizeof(cmd));
+    strncat(cmd, pandoc_versioned_args, sizeof(cmd) - strlen(cmd) - 1);
     if (css_file && strlen(css_file)) {
-        strcat(cmd, "--css ");
-        strcat(cmd, css_file);
+        strncat(cmd, "--css ", sizeof(cmd) - strlen(cmd) - 1);
+        strncat(cmd, css_file, sizeof(cmd) - strlen(cmd) - 1);
     }
-    strcat(cmd, " ");
-    strcat(cmd, "--metadata title=\"");
-    strcat(cmd, title);
-    strcat(cmd, "\" ");
-    strcat(cmd, "-o ");
-    strcat(cmd, out_file);
-    strcat(cmd, " ");
-    strcat(cmd, in_file);
+    strncat(cmd, " ", sizeof(cmd) - strlen(cmd) - 1);
+    strncat(cmd, "--metadata title=\"", sizeof(cmd) - strlen(cmd) - 1);
+    strncat(cmd, title, sizeof(cmd) - strlen(cmd) - 1);
+    strncat(cmd, "\" ", sizeof(cmd) - strlen(cmd) - 1);
+    strncat(cmd, "-o ", sizeof(cmd) - strlen(cmd) - 1);
+    strncat(cmd, out_file, sizeof(cmd) - strlen(cmd) - 1);
+    strncat(cmd, " ", sizeof(cmd) - strlen(cmd) - 1);
+    strncat(cmd, in_file, sizeof(cmd) - strlen(cmd) - 1);
 
     if (globals.verbose) {
         puts(cmd);
@@ -377,8 +377,8 @@ int write_manifest(const char *path, char **exclude_path, FILE *fp) {
         }
         char filepath[PATH_MAX] = {0};
         strncpy(filepath, path, PATH_MAX - 1);
-        strcat(filepath, "/");
-        strcat(filepath, rec->d_name);
+        strncat(filepath, "/", sizeof(filepath) - strlen(filepath) - 1);
+        strncat(filepath, rec->d_name, sizeof(filepath) - strlen(filepath) - 1);
         if (rec->d_type == DT_DIR) {
             write_manifest(filepath, exclude_path, fp);
             continue;
diff --git a/src/cli/stasis_indexer/stasis_indexer_main.c b/src/cli/stasis_indexer/stasis_indexer_main.c
index 5f7ded4..63fb45c 100644
--- a/src/cli/stasis_indexer/stasis_indexer_main.c
+++ b/src/cli/stasis_indexer/stasis_indexer_main.c
@@ -13,9 +13,9 @@ int indexer_combine_rootdirs(const char *dest, char **rootdirs, const size_t roo
     char destdir_with_output[PATH_MAX] = {0};
     char *destdir = destdir_bare;
 
-    strcpy(destdir_bare, dest);
-    strcpy(destdir_with_output, dest);
-    strcat(destdir_with_output, "/output");
+    strncpy(destdir_bare, dest, sizeof(destdir_bare) - 1);
+    strncpy(destdir_with_output, dest, sizeof(destdir_with_output) - 1);
+    strncat(destdir_with_output, "/output", sizeof(destdir_with_output) - strlen(destdir_with_output) - 1);
 
     if (!access(destdir_with_output, F_OK)) {
         destdir = destdir_with_output;
@@ -26,9 +26,9 @@ int indexer_combine_rootdirs(const char *dest, char **rootdirs, const size_t roo
         char srcdir_bare[PATH_MAX] = {0};
         char srcdir_with_output[PATH_MAX] = {0};
         char *srcdir = srcdir_bare;
-        strcpy(srcdir_bare, rootdirs[i]);
-        strcpy(srcdir_with_output, rootdirs[i]);
-        strcat(srcdir_with_output, "/output");
+        strncpy(srcdir_bare, rootdirs[i], sizeof(srcdir_bare) - 1);
+        strncpy(srcdir_with_output, rootdirs[i], sizeof(srcdir_with_output) - 1);
+        strncat(srcdir_with_output, "/output", sizeof(srcdir_with_output) - strlen(srcdir_with_output) - 1);
 
         if (access(srcdir_bare, F_OK)) {
             fprintf(stderr, "%s does not exist\n", srcdir_bare);
@@ -261,11 +261,11 @@ int main(const int argc, char *argv[]) {
     char workdir_template[PATH_MAX] = {0};
     const char *system_tmp = getenv("TMPDIR");
     if (system_tmp) {
-        strcat(workdir_template, system_tmp);
+        strncat(workdir_template, system_tmp, sizeof(workdir_template) - strlen(workdir_template) - 1);
     } else {
-        strcat(workdir_template, "/tmp");
+        strncat(workdir_template, "/tmp", sizeof(workdir_template) - strlen(workdir_template) - 1);
     }
-    strcat(workdir_template, "/stasis-combine.XXXXXX");
+    strncat(workdir_template, "/stasis-combine.XXXXXX", sizeof(workdir_template) - strlen(workdir_template) - 1);
     char *workdir = mkdtemp(workdir_template);
     if (!workdir) {
         SYSERROR("Unable to create temporary directory: %s", workdir_template);
diff --git a/src/cli/stasis_indexer/website.c b/src/cli/stasis_indexer/website.c
index e758d47..8a5126d 100644
--- a/src/cli/stasis_indexer/website.c
+++ b/src/cli/stasis_indexer/website.c
@@ -36,7 +36,7 @@ int indexer_make_website(struct Delivery **ctx) {
 
             // Replace *.md extension with *.html.
             strncpy(fullpath_dest, fullpath_src, sizeof(fullpath_dest) - 1);
-            gen_file_extension_str(fullpath_dest, ".html");
+            gen_file_extension_str(fullpath_dest, sizeof(fullpath_dest), ".html");
 
             // Convert markdown to html
             if (pandoc_exec(fullpath_src, fullpath_dest, have_css ? css_filename : NULL, "STASIS")) {
diff --git a/src/lib/core/artifactory.c b/src/lib/core/artifactory.c
index 6a01620..415986e 100644
--- a/src/lib/core/artifactory.c
+++ b/src/lib/core/artifactory.c
@@ -413,7 +413,7 @@ int jfrog_cli_rt_upload(struct JFRT_Auth *auth, struct JFRT_Upload *ctx, char *s
         if (base) {
             src = base;
         } else {
-            strcat(src, "/");
+            strncat(src, "/", sizeof(src) - strlen(src) - 1);
         }
         pushd(new_src);
     }
diff --git a/src/lib/core/conda.c b/src/lib/core/conda.c
index dd336bc..491eae3 100644
--- a/src/lib/core/conda.c
+++ b/src/lib/core/conda.c
@@ -419,15 +419,15 @@ int conda_check_required() {
 
     // Construct a "conda list" command that searches for all required packages
     // using conda's (python's) regex matching
-    strcat(cmd, "conda list '");
+    strncat(cmd, "conda list '", sizeof(cmd) - strlen(cmd) - 1);
     for (size_t i = 0; conda_minimum_viable_tools[i] != NULL; i++) {
-        strcat(cmd, "^");
-        strcat(cmd, conda_minimum_viable_tools[i]);
+        strncat(cmd, "^", sizeof(cmd) - strlen(cmd) - 1);
+        strncat(cmd, conda_minimum_viable_tools[i], sizeof(cmd) - strlen(cmd) - 1);
         if (conda_minimum_viable_tools[i + 1] != NULL) {
-            strcat(cmd, "|");
+            strncat(cmd, "|", sizeof(cmd) - strlen(cmd) - 1);
         }
     }
-    strcat(cmd, "' | cut -d ' ' -f 1");
+    strncat(cmd, "' | cut -d ' ' -f 1", sizeof(cmd) - strlen(cmd) - 1);
 
     // Verify all required packages are installed
     char *cmd_out = shell_output(cmd, &status);
@@ -565,7 +565,7 @@ int conda_env_create_from_uri(char *name, char *uri, char *python_version) {
     unlink(tempfile);
 
     // We'll create a new file with the same random bits, ending with .yml
-    strcat(tempfile, ".yml");
+    strncat(tempfile, ".yml", sizeof(tempfile) - strlen(tempfile) - 1);
     char *errmsg = NULL;
     const long http_code = download(uri_fs ? uri_fs : uri, tempfile, &errmsg);
     if (HTTP_ERROR(http_code)) {
diff --git a/src/lib/core/ini.c b/src/lib/core/ini.c
index cf6f670..6081678 100644
--- a/src/lib/core/ini.c
+++ b/src/lib/core/ini.c
@@ -186,8 +186,8 @@ int ini_getval(struct INIFILE *ini, char *section_name, char *key, int type, int
             while ((token = strsep(&tbufp, "\n")) != NULL) {
                 //lstrip(token);
                 if (!isempty(token)) {
-                    strcat(data_copy, token);
-                    strcat(data_copy, "\n");
+                    strncat(data_copy, token, BUFSIZ - strlen(data_copy) - 1);
+                    strncat(data_copy, "\n", BUFSIZ - strlen(data_copy) - 1);
                 }
             }
             strip(data_copy);
@@ -353,7 +353,7 @@ int ini_data_append(struct INIFILE **ini, char *section_name, char *key, char *v
         } else {
             data->value = value_tmp;
         }
-        strcat(data->value, value);
+        strncat(data->value, value, value_len_new - strlen(data->value));
     }
     return 0;
 }
@@ -467,7 +467,7 @@ int ini_write(struct INIFILE *ini, FILE **stream, unsigned mode) {
                 }
                 guard_array_free(parts);
                 strip(outvalue);
-                strcat(outvalue, LINE_SEP);
+                strncat(outvalue, LINE_SEP, sizeof(outvalue) - strlen(outvalue) - 1);
                 fprintf(*stream, "%s = %s%s", ini->section[x]->data[y]->key, *hint == INIVAL_TYPE_STR_ARRAY ? LINE_SEP : "", outvalue);
                 guard_free(value);
             } else {
diff --git a/src/lib/core/multiprocessing.c b/src/lib/core/multiprocessing.c
index f694ad6..09f81de 100644
--- a/src/lib/core/multiprocessing.c
+++ b/src/lib/core/multiprocessing.c
@@ -173,17 +173,17 @@ struct MultiProcessingTask *mp_pool_task(struct MultiProcessingPool *pool, const
     // Set log file path
     memset(slot->log_file, 0, sizeof(*slot->log_file));
     if (globals.enable_task_logging) {
-        strcat(slot->log_file, pool->log_root);
-        strcat(slot->log_file, "/");
+        strncat(slot->log_file, pool->log_root, sizeof(slot->log_file) - strlen(slot->log_file) - 1);
+        strncat(slot->log_file, "/", sizeof(slot->log_file) - strlen(slot->log_file) - 1);
     } else {
-        strcpy(slot->log_file, "/dev/stdout");
+        strncpy(slot->log_file, "/dev/stdout", sizeof(slot->log_file) - 1);
     }
 
     // Set working directory
     if (isempty(working_dir)) {
-        strcpy(slot->working_dir, ".");
+        strncpy(slot->working_dir, ".", sizeof(slot->working_dir) - 1);
     } else {
-        strncpy(slot->working_dir, working_dir, PATH_MAX - 1);
+        strncpy(slot->working_dir, working_dir, sizeof(slot->working_dir) - 1);
     }
 
     // Create a temporary file to act as our intermediate command script
diff --git a/src/lib/core/relocation.c b/src/lib/core/relocation.c
index 58b829d..fce74b6 100644
--- a/src/lib/core/relocation.c
+++ b/src/lib/core/relocation.c
@@ -50,18 +50,18 @@ int replace_text(char *original, const char *target, const char *replacement, un
             // replacement is shorter than the target
             if (rep_len < target_len) {
                 // shrink the string
-                strcat(buffer, replacement);
+                strncat(buffer, replacement, sizeof(buffer) - strlen(buffer) - 1);
                 memmove(pos, pos + target_len, strlen(pos) - target_len);
                 memset(pos + (strlen(pos) - target_len), 0, target_len);
             } else { // replacement is longer than the target
                 // write the replacement value to the buffer
-                strcat(buffer, replacement);
+                strncat(buffer, replacement, sizeof(buffer) - strlen(buffer) - 1);
                 // target consumed. jump to the end of the substring.
                 pos += target_len;
             }
             if (flags & REPLACE_TRUNCATE_AFTER_MATCH) {
                 if (strstr(pos, LINE_SEP)) {
-                    strcat(buffer, LINE_SEP);
+                    strncat(buffer, LINE_SEP, sizeof(buffer) - strlen(buffer) - 1);
                 }
                 break;
             }
@@ -69,7 +69,7 @@ int replace_text(char *original, const char *target, const char *replacement, un
             if (!((match = strstr(pos, target)))) {
                 // no more matches
                 // append whatever remains to the buffer
-                strcat(buffer, pos);
+                strncat(buffer, pos, sizeof(buffer) - strlen(buffer) - 1);
                 // stop
                 break;
             }
diff --git a/src/lib/core/str.c b/src/lib/core/str.c
index 9524886..c8f9c7e 100644
--- a/src/lib/core/str.c
+++ b/src/lib/core/str.c
@@ -153,9 +153,9 @@ char *join(char **arr, const char *separator) {
 
     result = (char *)calloc(total_bytes, sizeof(char));
     for (int i = 0; i < records; i++) {
-        strcat(result, arr[i]);
+        strncat(result, arr[i], total_bytes - strlen(result) - 1);
         if (i < (records - 1)) {
-            strcat(result, separator);
+            strncat(result, separator, total_bytes - strlen(result) - 1);
         }
     }
     return result;
@@ -207,11 +207,11 @@ char *join_ex(char *separator, ...) {
     result = calloc(size + 1, sizeof(char));
     for (size_t i = 0; i < argc; i++) {
         // Append argument to string
-        strcat(result, argv[i]);
+        strncat(result, argv[i], size - strlen(result)); // no -1 because +1 above
 
         // Do not append a trailing separator when we reach the last argument
         if (i < (argc - 1)) {
-            strcat(result, separator);
+            strncat(result, separator, size - strlen(result)); // no -1 because +1 above
         }
         guard_free(argv[i]);
     }
diff --git a/src/lib/core/system.c b/src/lib/core/system.c
index 9eff64a..6c18cc2 100644
--- a/src/lib/core/system.c
+++ b/src/lib/core/system.c
@@ -161,7 +161,7 @@ char *shell_output(const char *command, int *status) {
                 result = tmp;
             }
         }
-        strcat(result, line);
+        strncat(result, line, current_size - strlen(result) - 1);
         memset(line, 0, sizeof(line));
     }
     *status = pclose(pp);
diff --git a/src/lib/core/template.c b/src/lib/core/template.c
index dd3c7a2..67e2e03 100644
--- a/src/lib/core/template.c
+++ b/src/lib/core/template.c
@@ -272,7 +272,7 @@ char *tpl_render(char *str) {
 
             // Append replacement value
             grow(z, &output_bytes, &output);
-            strcat(output, value);
+            strncat(output, value, output_bytes - strlen(output) - 1);
             guard_free(value);
             output[z] = 0;
         }
diff --git a/src/lib/core/utils.c b/src/lib/core/utils.c
index 76b314e..f478205 100644
--- a/src/lib/core/utils.c
+++ b/src/lib/core/utils.c
@@ -45,9 +45,9 @@ int rmtree(char *_path) {
 
     while ((d_entity = readdir(dir)) != NULL) {
         char abspath[PATH_MAX] = {0};
-        strcat(abspath, path);
-        strcat(abspath, DIR_SEP);
-        strcat(abspath, d_entity->d_name);
+        strncat(abspath, path, sizeof(abspath) - strlen(abspath) - 1);
+        strncat(abspath, DIR_SEP, sizeof(abspath) - strlen(abspath) - 1);
+        strncat(abspath, d_entity->d_name, sizeof(abspath) - strlen(abspath) - 1);
 
         if (!strcmp(d_entity->d_name, ".") || !strcmp(d_entity->d_name, "..") || !strcmp(abspath, path)) {
             continue;
@@ -278,13 +278,13 @@ char *find_program(const char *name) {
     result[0] = '\0';
     while ((path_elem = strsep(&path, PATH_SEP))) {
         char abspath[PATH_MAX] = {0};
-        strcat(abspath, path_elem);
-        strcat(abspath, DIR_SEP);
-        strcat(abspath, name);
+        strncat(abspath, path_elem, sizeof(abspath) - strlen(abspath) - 1);
+        strncat(abspath, DIR_SEP, sizeof(abspath) - strlen(abspath) - 1);
+        strncat(abspath, name, sizeof(abspath) - strlen(abspath) - 1);
         if (access(abspath, F_OK) < 0) {
             continue;
         }
-        strncpy(result, abspath, sizeof(result));
+        strncpy(result, abspath, sizeof(result) - 1);
         break;
     }
     path = path_orig;
@@ -694,7 +694,7 @@ int fix_tox_conf(const char *filename, char **result) {
                                 return -1;
                             }
                             value = tmp;
-                            strcat(value, with_posargs);
+                            strncat(value, with_posargs, (strlen(value) + strlen(with_posargs)) - strlen(value) - 1);
                             ini_setval(&toxini, INI_SETVAL_REPLACE, section_name, key, value);
                         }
                     }
@@ -829,8 +829,8 @@ int mkdirs(const char *_path, mode_t mode) {
     char result[PATH_MAX] = {0};
     int status = 0;
     while ((token = strsep(&path, "/")) != NULL && !status) {
-        strcat(result, token);
-        strcat(result, "/");
+        strncat(result, token, sizeof result - strlen(result) - 1);
+        strncat(result, "/", sizeof result - strlen(result) - 1);
         status = mkdir(result, mode);
         if (status && errno == EEXIST) {
             status = 0;
@@ -919,7 +919,7 @@ void debug_hexdump(char *data, int len) {
             snprintf(addr + strlen(addr), sizeof(addr) - pos_fmt_len, pos_fmt, pos);
         }
         if (count == 8) {
-            strcat(bytes, " ");
+            strncat(bytes, " ", sizeof(bytes) - strlen(bytes) - 1);
         }
         if (count > 15) {
             snprintf(output, sizeof(output), "%s | %s | %s", addr, bytes, ascii);
@@ -946,11 +946,11 @@ void debug_hexdump(char *data, int len) {
 
     if (count <= 8) {
         // Add group padding
-        strcat(bytes, " ");
+        strncat(bytes, " ", sizeof(bytes) - strlen(bytes) - 1);
     }
     const int padding = 16 - count;
     for (int i = 0; i < padding; i++) {
-        strcat(bytes, "   ");
+        strncat(bytes, "   ", sizeof(bytes) - strlen(bytes) - 1);
     }
     snprintf(output, DEBUG_HEXDUMP_FMT_BYTES + sizeof(addr) + sizeof(bytes) + sizeof(ascii), "%s | %s | %s", addr, bytes, ascii);
     puts(output);
diff --git a/src/lib/delivery/delivery_install.c b/src/lib/delivery/delivery_install.c
index fe3bc66..4970749 100644
--- a/src/lib/delivery/delivery_install.c
+++ b/src/lib/delivery/delivery_install.c
@@ -203,7 +203,7 @@ int delivery_install_packages(struct Delivery *ctx, char *conda_install_dir, cha
     }
 
     memset(command_base, 0, sizeof(command_base));
-    strcat(command_base, "install");
+    strncat(command_base, "install", sizeof(command_base) - strlen(command_base) - 1);
 
     typedef int (*Runner)(const char *);
     Runner runner = NULL;
@@ -214,13 +214,13 @@ int delivery_install_packages(struct Delivery *ctx, char *conda_install_dir, cha
     }
 
     if (INSTALL_PKG_CONDA_DEFERRED & type) {
-        strcat(command_base, " --use-local");
+        strncat(command_base, " --use-local", sizeof(command_base) - strlen(command_base) - 1);
     } else if (INSTALL_PKG_PIP_DEFERRED & type) {
         // Don't change the baseline package set unless we're working with a
         // new build. Release candidates will need to keep packages as stable
         // as possible between releases.
         if (!ctx->meta.based_on) {
-            strcat(command_base, " --upgrade");
+            strncat(command_base, " --upgrade", sizeof(command_base) - strlen(command_base) - 1);
         }
         const char *command_base_fmt = " --extra-index-url 'file://%s'";
         const int len = snprintf(NULL, 0, command_base_fmt, ctx->storage.wheel_artifact_dir);