From e2e57d637aa5da0a2f49d83ad44e9febf95df7b4 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Thu, 9 Nov 2023 22:14:11 -0800 Subject: selftests/bpf: add more test cases for check_cfg() Add a few more simple cases to validate proper privileged vs unprivileged loop detection behavior. conditional_loop2 is the one reported by Hao Sun that triggered this set of fixes. Acked-by: Eduard Zingerman Suggested-by: Hao Sun Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20231110061412.2995786-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/progs/verifier_cfg.c | 62 ++++++++++++++++++++++++ 1 file changed, 62 insertions(+) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/progs/verifier_cfg.c b/tools/testing/selftests/bpf/progs/verifier_cfg.c index df7697b94007..c1f55e1d80a4 100644 --- a/tools/testing/selftests/bpf/progs/verifier_cfg.c +++ b/tools/testing/selftests/bpf/progs/verifier_cfg.c @@ -97,4 +97,66 @@ l0_%=: r2 = r0; \ " ::: __clobber_all); } +SEC("socket") +__description("conditional loop (2)") +__success +__failure_unpriv __msg_unpriv("back-edge from insn 10 to 11") +__naked void conditional_loop2(void) +{ + asm volatile (" \ + r9 = 2 ll; \ + r3 = 0x20 ll; \ + r4 = 0x35 ll; \ + r8 = r4; \ + goto l1_%=; \ +l0_%=: r9 -= r3; \ + r9 -= r4; \ + r9 -= r8; \ +l1_%=: r8 += r4; \ + if r8 < 0x64 goto l0_%=; \ + r0 = r9; \ + exit; \ +" ::: __clobber_all); +} + +SEC("socket") +__description("unconditional loop after conditional jump") +__failure __msg("infinite loop detected") +__failure_unpriv __msg_unpriv("back-edge from insn 3 to 2") +__naked void uncond_loop_after_cond_jmp(void) +{ + asm volatile (" \ + r0 = 0; \ + if r0 > 0 goto l1_%=; \ +l0_%=: r0 = 1; \ + goto l0_%=; \ +l1_%=: exit; \ +" ::: __clobber_all); +} + + +__naked __noinline __used +static unsigned long never_ending_subprog() +{ + asm volatile (" \ + r0 = r1; \ + goto -1; \ +" ::: __clobber_all); +} + +SEC("socket") +__description("unconditional loop after conditional jump") +/* infinite loop is detected *after* check_cfg() */ +__failure __msg("infinite loop detected") +__naked void uncond_loop_in_subprog_after_cond_jmp(void) +{ + asm volatile (" \ + r0 = 0; \ + if r0 > 0 goto l1_%=; \ +l0_%=: r0 += 1; \ + call never_ending_subprog; \ +l1_%=: exit; \ +" ::: __clobber_all); +} + char _license[] SEC("license") = "GPL"; -- cgit v1.2.3