diff options
Diffstat (limited to 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 34 |
1 files changed, 27 insertions, 7 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index d85f37239540..4e6dee19a668 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -623,9 +623,20 @@ 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 */ @@ -1485,8 +1496,10 @@ 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; @@ -2283,7 +2296,7 @@ static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) } #endif -const struct file_operations bpf_link_fops = { +static const struct file_operations bpf_link_fops = { #ifdef CONFIG_PROC_FS .show_fdinfo = bpf_link_show_fdinfo, #endif @@ -3628,8 +3641,10 @@ static int link_update(union bpf_attr *attr) return PTR_ERR(link); new_prog = bpf_prog_get(attr->link_update.new_prog_fd); - if (IS_ERR(new_prog)) - return PTR_ERR(new_prog); + if (IS_ERR(new_prog)) { + ret = PTR_ERR(new_prog); + goto out_put_link; + } if (flags & BPF_F_REPLACE) { old_prog = bpf_prog_get(attr->link_update.old_prog_fd); @@ -3638,6 +3653,9 @@ static int link_update(union bpf_attr *attr) old_prog = NULL; goto out_put_progs; } + } else if (attr->link_update.old_prog_fd) { + ret = -EINVAL; + goto out_put_progs; } #ifdef CONFIG_CGROUP_BPF @@ -3653,6 +3671,8 @@ out_put_progs: bpf_prog_put(old_prog); if (ret) bpf_prog_put(new_prog); +out_put_link: + bpf_link_put(link); return ret; } |