From 33772ff3b887eb2f426ed66bcb1808837a40669c Mon Sep 17 00:00:00 2001 From: Hao Sun Date: Mon, 15 Jan 2024 09:20:28 +0100 Subject: selftests/bpf: Add test for alu on PTR_TO_FLOW_KEYS Add a test case for PTR_TO_FLOW_KEYS alu. Testing if alu with variable offset on flow_keys is rejected. For the fixed offset success case, we already have C code coverage to verify (e.g. via bpf_flow.c). Signed-off-by: Hao Sun Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20240115082028.9992-2-sunhao.th@gmail.com --- .../selftests/bpf/progs/verifier_value_illegal_alu.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'tools/testing') diff --git a/tools/testing/selftests/bpf/progs/verifier_value_illegal_alu.c b/tools/testing/selftests/bpf/progs/verifier_value_illegal_alu.c index 71814a753216..a9ab37d3b9e2 100644 --- a/tools/testing/selftests/bpf/progs/verifier_value_illegal_alu.c +++ b/tools/testing/selftests/bpf/progs/verifier_value_illegal_alu.c @@ -146,4 +146,23 @@ l0_%=: exit; \ : __clobber_all); } +SEC("flow_dissector") +__description("flow_keys illegal alu op with variable offset") +__failure __msg("R7 pointer arithmetic on flow_keys prohibited") +__naked void flow_keys_illegal_variable_offset_alu(void) +{ + asm volatile(" \ + r6 = r1; \ + r7 = *(u64*)(r6 + %[flow_keys_off]); \ + r8 = 8; \ + r8 /= 1; \ + r8 &= 8; \ + r7 += r8; \ + r0 = *(u64*)(r7 + 0); \ + exit; \ +" : + : __imm_const(flow_keys_off, offsetof(struct __sk_buff, flow_keys)) + : __clobber_all); +} + char _license[] SEC("license") = "GPL"; -- cgit v1.2.3