diff options
Diffstat (limited to 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 3b92aea18ae7..c0ab9bfdf28a 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -629,9 +629,20 @@ static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma) mutex_lock(&map->freeze_mutex); - if ((vma->vm_flags & VM_WRITE) && map->frozen) { - err = -EPERM; - goto out; + if (vma->vm_flags & VM_WRITE) { + if (map->frozen) { + err = -EPERM; + goto out; + } + /* map is meant to be read-only, so do not allow mapping as + * writable, because it's possible to leak a writable page + * reference and allows user-space to still modify it after + * freezing, while verifier will assume contents do not change + */ + if (map->map_flags & BPF_F_RDONLY_PROG) { + err = -EACCES; + goto out; + } } /* set default open/close callbacks */ @@ -1480,8 +1491,10 @@ static int map_lookup_and_delete_elem(union bpf_attr *attr) if (err) goto free_value; - if (copy_to_user(uvalue, value, value_size) != 0) + if (copy_to_user(uvalue, value, value_size) != 0) { + err = -EFAULT; goto free_value; + } err = 0; |