From 2cb7fe5d4c707d8f5663829bacf2606648be185a Mon Sep 17 00:00:00 2001 From: KaFai Wan Date: Wed, 1 Oct 2025 11:56:51 +0800 Subject: [PATCH] selftests/bpf: Add test for BPF_NEG alu on CONST_PTR_TO_MAP From: KaFai Wan Add a test case for BPF_NEG operation on CONST_PTR_TO_MAP. Tests if BPF_NEG operation on map_ptr is rejected in unprivileged mode and is a scalar value and do not trigger Oops in privileged mode. Signed-off-by: KaFai Wan --- .../bpf/progs/verifier_value_illegal_alu.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) 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 a99b86c506f7..a850dde95d0e 100644 --- a/tools/testing/selftests/bpf/progs/verifier_value_illegal_alu.c +++ b/tools/testing/selftests/bpf/progs/verifier_value_illegal_alu.c @@ -182,6 +182,24 @@ __naked void map_ptr_illegal_alu_op(void) : __clobber_all); } +SEC("socket") +__description("map_ptr illegal alu op, map_ptr = -map_ptr") +__failure __msg("R0 invalid mem access 'scalar'") +__failure_unpriv __msg_unpriv("R0 pointer arithmetic prohibited") +__flag(BPF_F_ANY_ALIGNMENT) +__naked void map_ptr_illegal_alu_op(void) +{ + asm volatile (" \ + r0 = %[map_hash_48b] ll; \ + r0 = -r0; \ + r1 = 22; \ + *(u64*)(r0 + 0) = r1; \ + exit; \ +" : + : __imm_addr(map_hash_48b) + : __clobber_all); +} + SEC("flow_dissector") __description("flow_keys illegal alu op with variable offset") __failure __msg("R7 pointer arithmetic on flow_keys prohibited") -- 2.43.0