variable used but uninitialized

[Rémi]

Hy everyone, I need your help !
I'm doing a little code for school but I have an issue : when I try to compile my code I have the following warning : "warning: 'nom' is used uninitialized [-Wuninitialized]".
My issue is that nom is initialized two line above. Is someone could help me ?

char *demande_nom1()
{
  char *nom;
  printf("Quel est le nom de l'image d'origine ?");
  scanf("%s", nom);
  return nom;
}

PS: yes i'm french