From 63a9936b45859b24780c86c32a32fc7b087c304e Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Tue, 23 Jul 2024 08:34:44 -0700 Subject: [PATCH] selftests/bpf: Add tests for ldsx of pkt data/data_end/data_meta accesses The following tests are added to verifier_ldsx.c: - sign extension of data/data_end/data_meta for tcx programs. The actual checking is in bpf_skb_is_valid_access() which is called by sk_filter, cg_skb, lwt, tc(tcx) and sk_skb. - sign extension of data/data_end/data_meta for xdp programs. - sign extension of data/data_end for flow_dissector programs. All newly-added tests have verification failure with message "invalid bpf_context access". Without previous patch, all these tests succeeded verification. Acked-by: Eduard Zingerman Signed-off-by: Yonghong Song Link: https://lore.kernel.org/r/20240723153444.2430365-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov Signed-off-by: Andrii Nakryiko --- .../selftests/bpf/progs/verifier_ldsx.c | 112 ++++++++++++++++++ 1 file changed, 112 insertions(+) diff --git a/tools/testing/selftests/bpf/progs/verifier_ldsx.c b/tools/testing/selftests/bpf/progs/verifier_ldsx.c index d4427d8e12174..52edee41caf67 100644 --- a/tools/testing/selftests/bpf/progs/verifier_ldsx.c +++ b/tools/testing/selftests/bpf/progs/verifier_ldsx.c @@ -144,6 +144,118 @@ __naked void ldsx_s32_range(void) : __clobber_all); } +SEC("xdp") +__description("LDSX, xdp s32 xdp_md->data") +__failure __msg("invalid bpf_context access") +__naked void ldsx_ctx_1(void) +{ + asm volatile ( + "r2 = *(s32 *)(r1 + %[xdp_md_data]);" + "r0 = 0;" + "exit;" + : + : __imm_const(xdp_md_data, offsetof(struct xdp_md, data)) + : __clobber_all); +} + +SEC("xdp") +__description("LDSX, xdp s32 xdp_md->data_end") +__failure __msg("invalid bpf_context access") +__naked void ldsx_ctx_2(void) +{ + asm volatile ( + "r2 = *(s32 *)(r1 + %[xdp_md_data_end]);" + "r0 = 0;" + "exit;" + : + : __imm_const(xdp_md_data_end, offsetof(struct xdp_md, data_end)) + : __clobber_all); +} + +SEC("xdp") +__description("LDSX, xdp s32 xdp_md->data_meta") +__failure __msg("invalid bpf_context access") +__naked void ldsx_ctx_3(void) +{ + asm volatile ( + "r2 = *(s32 *)(r1 + %[xdp_md_data_meta]);" + "r0 = 0;" + "exit;" + : + : __imm_const(xdp_md_data_meta, offsetof(struct xdp_md, data_meta)) + : __clobber_all); +} + +SEC("tcx/ingress") +__description("LDSX, tcx s32 __sk_buff->data") +__failure __msg("invalid bpf_context access") +__naked void ldsx_ctx_4(void) +{ + asm volatile ( + "r2 = *(s32 *)(r1 + %[sk_buff_data]);" + "r0 = 0;" + "exit;" + : + : __imm_const(sk_buff_data, offsetof(struct __sk_buff, data)) + : __clobber_all); +} + +SEC("tcx/ingress") +__description("LDSX, tcx s32 __sk_buff->data_end") +__failure __msg("invalid bpf_context access") +__naked void ldsx_ctx_5(void) +{ + asm volatile ( + "r2 = *(s32 *)(r1 + %[sk_buff_data_end]);" + "r0 = 0;" + "exit;" + : + : __imm_const(sk_buff_data_end, offsetof(struct __sk_buff, data_end)) + : __clobber_all); +} + +SEC("tcx/ingress") +__description("LDSX, tcx s32 __sk_buff->data_meta") +__failure __msg("invalid bpf_context access") +__naked void ldsx_ctx_6(void) +{ + asm volatile ( + "r2 = *(s32 *)(r1 + %[sk_buff_data_meta]);" + "r0 = 0;" + "exit;" + : + : __imm_const(sk_buff_data_meta, offsetof(struct __sk_buff, data_meta)) + : __clobber_all); +} + +SEC("flow_dissector") +__description("LDSX, flow_dissector s32 __sk_buff->data") +__failure __msg("invalid bpf_context access") +__naked void ldsx_ctx_7(void) +{ + asm volatile ( + "r2 = *(s32 *)(r1 + %[sk_buff_data]);" + "r0 = 0;" + "exit;" + : + : __imm_const(sk_buff_data, offsetof(struct __sk_buff, data)) + : __clobber_all); +} + +SEC("flow_dissector") +__description("LDSX, flow_dissector s32 __sk_buff->data_end") +__failure __msg("invalid bpf_context access") +__naked void ldsx_ctx_8(void) +{ + asm volatile ( + "r2 = *(s32 *)(r1 + %[sk_buff_data_end]);" + "r0 = 0;" + "exit;" + : + : __imm_const(sk_buff_data_end, offsetof(struct __sk_buff, data_end)) + : __clobber_all); +} + #else SEC("socket")