kern: proc: Add NULL check for envblk

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/src/sys/os/os_proc.c b/src/sys/os/os_proc.c
index 764b3f2..565c663 100644
--- a/src/sys/os/os_proc.c
+++ b/src/sys/os/os_proc.c
@@ -429,13 +429,17 @@ sys_getargv(struct syscall_args *scargs)
     char *u_buf = SCARG(scargs, char *, 1);
     size_t maxlen = SCARG(scargs, size_t, 2);
     struct proc *self = proc_self();
-    struct penv_blk *envblk = self->envblk;
+    struct penv_blk *envblk;
     char *arg;
 
     if (argno >= envblk->argc) {
         return -EINVAL;
     }
 
+    if ((envblk = self->envblk) == NULL) {
+        return -EIO;
+    }
+
     arg = envblk->argv[argno];
     return copyoutstr(arg, u_buf, maxlen);
 }