From db123e42304d5bba9a1e04341db0cafaa7a52f35 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Wed, 16 Oct 2024 15:49:13 +0200 Subject: [PATCH] selftests/bpf: Add test case for delta propagation Add a small BPF verifier test case to ensure that alu32 additions to registers are not subject to linked scalar delta tracking. # ./vmtest.sh -- ./test_progs -t verifier_linked_scalars [...] ./test_progs -t verifier_linked_scalars [ 1.413138] tsc: Refined TSC clocksource calibration: 3407.993 MHz [ 1.413524] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x311fcd52370, max_idle_ns: 440795242006 ns [ 1.414223] clocksource: Switched to clocksource tsc [ 1.419640] bpf_testmod: loading out-of-tree module taints kernel. [ 1.420025] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel #500/1 verifier_linked_scalars/scalars: find linked scalars:OK #500 verifier_linked_scalars:OK Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED [ 1.590858] ACPI: PM: Preparing to enter system sleep state S5 [ 1.591402] reboot: Power down [...] Signed-off-by: Daniel Borkmann Signed-off-by: Andrii Nakryiko Acked-by: Eduard Zingerman Link: https://lore.kernel.org/bpf/20241016134913.32249-3-daniel@iogearbox.net --- .../selftests/bpf/prog_tests/verifier.c | 2 ++ .../bpf/progs/verifier_linked_scalars.c | 34 +++++++++++++++++++ 2 files changed, 36 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/verifier_linked_scalars.c diff --git a/tools/testing/selftests/bpf/prog_tests/verifier.c b/tools/testing/selftests/bpf/prog_tests/verifier.c index e26b5150fc43..5356f26bbb3f 100644 --- a/tools/testing/selftests/bpf/prog_tests/verifier.c +++ b/tools/testing/selftests/bpf/prog_tests/verifier.c @@ -44,6 +44,7 @@ #include "verifier_ld_ind.skel.h" #include "verifier_ldsx.skel.h" #include "verifier_leak_ptr.skel.h" +#include "verifier_linked_scalars.skel.h" #include "verifier_loops1.skel.h" #include "verifier_lwt.skel.h" #include "verifier_map_in_map.skel.h" @@ -170,6 +171,7 @@ void test_verifier_jit_convergence(void) { RUN(verifier_jit_convergence); } void test_verifier_ld_ind(void) { RUN(verifier_ld_ind); } void test_verifier_ldsx(void) { RUN(verifier_ldsx); } void test_verifier_leak_ptr(void) { RUN(verifier_leak_ptr); } +void test_verifier_linked_scalars(void) { RUN(verifier_linked_scalars); } void test_verifier_loops1(void) { RUN(verifier_loops1); } void test_verifier_lwt(void) { RUN(verifier_lwt); } void test_verifier_map_in_map(void) { RUN(verifier_map_in_map); } diff --git a/tools/testing/selftests/bpf/progs/verifier_linked_scalars.c b/tools/testing/selftests/bpf/progs/verifier_linked_scalars.c new file mode 100644 index 000000000000..8f755d2464cf --- /dev/null +++ b/tools/testing/selftests/bpf/progs/verifier_linked_scalars.c @@ -0,0 +1,34 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include "bpf_misc.h" + +SEC("socket") +__description("scalars: find linked scalars") +__failure +__msg("math between fp pointer and 2147483647 is not allowed") +__naked void scalars(void) +{ + asm volatile (" \ + r0 = 0; \ + r1 = 0x80000001 ll; \ + r1 /= 1; \ + r2 = r1; \ + r4 = r1; \ + w2 += 0x7FFFFFFF; \ + w4 += 0; \ + if r2 == 0 goto l1; \ + exit; \ +l1: \ + r4 >>= 63; \ + r3 = 1; \ + r3 -= r4; \ + r3 *= 0x7FFFFFFF; \ + r3 += r10; \ + *(u8*)(r3 - 1) = r0; \ + exit; \ +" ::: __clobber_all); +} + +char _license[] SEC("license") = "GPL"; -- 2.49.0