diff --git a/tools/testing/selftests/bpf/progs/verifier_bounds.c b/tools/testing/selftests/bpf/progs/verifier_bounds.c index df8d5309657e..05efa9f4a522 100644 --- a/tools/testing/selftests/bpf/progs/verifier_bounds.c +++ b/tools/testing/selftests/bpf/progs/verifier_bounds.c @@ -2159,6 +2159,47 @@ l0_%=: r0 = 0; \ : __clobber_all); } +/* + * The insn that forks is the head of a loop that scalar evolution counted. The state with + * [-1, 0] is kept there, and the state with 0 that is split off is within it. + */ +SEC("socket") +__description("maybe_fork_scalars: AND at the head of a counted loop rejects OOB") +__failure __msg("invalid access to map value") +__naked void and_scalar_fork_at_long_loop_head_rejects_oob(void) +{ + asm volatile (" \ + r1 = 0; \ + *(u64*)(r10 - 8) = r1; \ + r2 = r10; \ + r2 += -8; \ + r1 = %[map_hash_8b] ll; \ + call %[bpf_map_lookup_elem]; \ + if r0 == 0 goto l0_%=; \ + r9 = r0; \ + r7 = 0; \ + r6 = -1; \ +l1_%=: r6 &= 8; \ + /* r6 is 8 (current) or 0 (pushed) */ \ + r6 ^= 8; \ + /* pushed path: r6 = 8, OOB for value_size=8 */ \ + r1 = r9; \ + r1 += r6; \ + r0 = *(u8*)(r1 + 0); \ + r1 = *(u64*)(r9 + 0); \ + r6 = -1; \ + if r1 == 0 goto l2_%=; \ + r6 = 0; \ +l2_%=: r7 += 1; \ + if r7 < 100 goto l1_%=; \ +l0_%=: r0 = 0; \ + exit; \ +" : + : __imm(bpf_map_lookup_elem), + __imm_addr(map_hash_8b) + : __clobber_all); +} + /* * Last jump can be detected as always taken because the intersection of R5 and * R7 32bit tnums produces a constant that isn't within R7's s32 bounds.