diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c index 97f50e9fd9eb..297487ee8323 100644 --- a/fs/afs/mntpt.c +++ b/fs/afs/mntpt.c @@ -140,6 +140,11 @@ static int afs_mntpt_set_params(struct fs_context *fc, struct dentry *mntpt) put_page(page); if (ret < 0) return ret; + + /* Don't cross a backup volume mountpoint from a backup volume */ + if (src_as->volume && src_as->volume->type == AFSVL_BACKVOL && + ctx->type == AFSVL_BACKVOL) + return -ENODEV; } return 0;