fix: fetch_git buffer overflow and error checks

1 files changed, 51 insertions, 35 deletions

diff --git a/src/fetch_git.c b/src/fetch_git.c
index b3e4314..570cb1d 100644
--- a/src/fetch_git.c
+++ b/src/fetch_git.c
@@ -29,40 +29,56 @@
 #include "vars.h"
 
 int fetch_git(Pkg pkg) {
-  pid_t pid = fork();
-  if (pid == 0) {
-    if (!is_verbose) {
-      int nullfd = open("/dev/null", O_WRONLY);
-      if (nullfd >= 0) {
-        dup2(nullfd, STDOUT_FILENO);
-        dup2(nullfd, STDERR_FILENO);
-        close(nullfd);
-      }
+    if (pkg.url == NULL || pkg.src == NULL) {
+        fprintf(stderr, "%s invalid pkg: url or src is NULL\n", print_warning);
+        return -1;
     }
-    const char *argv[8];
-    int i = 0;
-    argv[i++] = "git";
-    argv[i++] = "-c";
-    argv[i++] = "advice.detachedHead=false";
-    argv[i++] = "clone";
-    if (strcmp(pkg.ver, "HEAD") != 0) {
-      argv[i++] = "--branch";
-      argv[i++] = pkg.ver;
+
+    pid_t pid = fork();
+    if (pid < 0) {
+        perror("fork failed");
+        return -1;
     }
-    argv[i++] = "--recursive";
-    argv[i++] = pkg.url;
-    argv[i++] = pkg.src;
-    argv[i] = NULL;
-    execvp("git", (char *const *)argv);
-    _exit(127);
-  }
-
-  int status;
-  waitpid(pid, &status, 0);
-  int result = WIFEXITED(status) ? WEXITSTATUS(status) : -1;
-  if (result != 0) {
-    printf("%s git clone failed: %d\n", print_warning, result);
-  }
-
-  return result;
-}
\ No newline at end of file
+
+    if (pid == 0) {
+        if (!is_verbose) {
+            int nullfd = open("/dev/null", O_WRONLY);
+            if (nullfd >= 0) {
+                dup2(nullfd, STDOUT_FILENO);
+                dup2(nullfd, STDERR_FILENO);
+                close(nullfd);
+            }
+         }
+ 
+        const char *argv[12];
+        int i = 0;
+
+        argv[i++] = "git";
+        argv[i++] = "-c";
+        argv[i++] = "advice.detachedHead=false";
+        argv[i++] = "clone";
+
+        if (pkg.ver != NULL && strcmp(pkg.ver, "HEAD") != 0) {
+            argv[i++] = "--branch";
+            argv[i++] = pkg.ver;
+        }
+
+        argv[i++] = "--recursive";
+        argv[i++] = pkg.url;
+        argv[i++] = pkg.src;
+        argv[i] = NULL;
+
+        execvp("git", (char *const *)argv);
+        _exit(127);
+    }
+
+    int status;
+    waitpid(pid, &status, 0);
+
+    int result = WIFEXITED(status) ? WEXITSTATUS(status) : -1;
+    if (result != 0) {
+        printf("%s git clone failed: %d\n", print_warning, result);
+    }
+
+    return result;
+}