Commit 8addbfc7 authored by Kumar Kartikeya Dwivedi's avatar Kumar Kartikeya Dwivedi Committed by Alexei Starovoitov
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bpf: Gate dynptr API behind CAP_BPF 



This has been enabled for unprivileged programs for only one kernel
release, hence the expected annoyances due to this move are low. Users
using ringbuf can stick to non-dynptr APIs. The actual use cases dynptr
is meant to serve may not make sense in unprivileged BPF programs.

Hence, gate these helpers behind CAP_BPF and limit use to privileged
BPF programs.

Fixes: 263ae152 ("bpf: Add bpf_dynptr_from_mem for local dynptrs")
Fixes: bc34dee6 ("bpf: Dynptr support for ring buffers")
Fixes: 13bbbfbe ("bpf: Add bpf_dynptr_read and bpf_dynptr_write")
Fixes: 34d4ef57 ("bpf: Add dynptr data slices")
Signed-off-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220921143550.30247-1-memxor@gmail.com


Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent d703256f

kernel/bpf/helpers.c

+14 −14
Original line number Diff line number Diff line
@@ -1627,26 +1627,12 @@ bpf_base_func_proto(enum bpf_func_id func_id) 
		return &bpf_ringbuf_discard_proto;

	case BPF_FUNC_ringbuf_query:

		return &bpf_ringbuf_query_proto;

	case BPF_FUNC_ringbuf_reserve_dynptr:

		return &bpf_ringbuf_reserve_dynptr_proto;

	case BPF_FUNC_ringbuf_submit_dynptr:

		return &bpf_ringbuf_submit_dynptr_proto;

	case BPF_FUNC_ringbuf_discard_dynptr:

		return &bpf_ringbuf_discard_dynptr_proto;

	case BPF_FUNC_for_each_map_elem:

		return &bpf_for_each_map_elem_proto;

	case BPF_FUNC_loop:

		return &bpf_loop_proto;

	case BPF_FUNC_strncmp:

		return &bpf_strncmp_proto;

	case BPF_FUNC_dynptr_from_mem:

		return &bpf_dynptr_from_mem_proto;

	case BPF_FUNC_dynptr_read:

		return &bpf_dynptr_read_proto;

	case BPF_FUNC_dynptr_write:

		return &bpf_dynptr_write_proto;

	case BPF_FUNC_dynptr_data:

		return &bpf_dynptr_data_proto;

	default:

		break;

	}
@@ -1675,6 +1661,20 @@ bpf_base_func_proto(enum bpf_func_id func_id) 
		return &bpf_timer_cancel_proto;

	case BPF_FUNC_kptr_xchg:

		return &bpf_kptr_xchg_proto;

	case BPF_FUNC_ringbuf_reserve_dynptr:

		return &bpf_ringbuf_reserve_dynptr_proto;

	case BPF_FUNC_ringbuf_submit_dynptr:

		return &bpf_ringbuf_submit_dynptr_proto;

	case BPF_FUNC_ringbuf_discard_dynptr:

		return &bpf_ringbuf_discard_dynptr_proto;

	case BPF_FUNC_dynptr_from_mem:

		return &bpf_dynptr_from_mem_proto;

	case BPF_FUNC_dynptr_read:

		return &bpf_dynptr_read_proto;

	case BPF_FUNC_dynptr_write:

		return &bpf_dynptr_write_proto;

	case BPF_FUNC_dynptr_data:

		return &bpf_dynptr_data_proto;

	default:

		break;

	}