On 10/17/19 11:09 PM, Alexei Starovoitov wrote:
> Only raw_tracepoint program type can have bpf_attr.attach_btf_id >= 0.
> Make sure to reject other program types that accidentally set it to non-zero.
>
> Fixes: ccfe29eb29c2 ("bpf: Add attach_btf_id attribute to program load")
> Reported-by: Andrii Nakryiko <andriin@xxxxxx>
> Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Acked-by: Yonghong Song <yhs@xxxxxx>
> ---
> kernel/bpf/syscall.c | 17 +++++++++++------
> 1 file changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
> index 523e3ac15a08..16ea3c0db4f6 100644
> --- a/kernel/bpf/syscall.c
> +++ b/kernel/bpf/syscall.c
> @@ -1570,6 +1570,17 @@ bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
> enum bpf_attach_type expected_attach_type,
> u32 btf_id)
> {
> + switch (prog_type) {
> + case BPF_PROG_TYPE_RAW_TRACEPOINT:
> + if (btf_id > BTF_MAX_TYPE)
> + return -EINVAL;
> + break;
> + default:
> + if (btf_id)
> + return -EINVAL;
> + break;
> + }
> +
> switch (prog_type) {
> case BPF_PROG_TYPE_CGROUP_SOCK:
> switch (expected_attach_type) {
> @@ -1610,13 +1621,7 @@ bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
> default:
> return -EINVAL;
> }
> - case BPF_PROG_TYPE_RAW_TRACEPOINT:
> - if (btf_id > BTF_MAX_TYPE)
> - return -EINVAL;
> - return 0;
> default:
> - if (btf_id)
> - return -EINVAL;
> return 0;
> }
> }
>
