Commit 2e3f0660 authored by Daniel Borkmann's avatar Daniel Borkmann Committed by Alexei Starovoitov
Browse files

selftests/bpf: Add a test case to write strtol result into .rodata 



Add a test case which attempts to write into .rodata section of the
BPF program, and for comparison this adds test cases also for .bss
and .data section.

Before fix:

  # ./vmtest.sh -- ./test_progs -t verifier_const
  [...]
  ./test_progs -t verifier_const
  tester_init:PASS:tester_log_buf 0 nsec
  process_subtest:PASS:obj_open_mem 0 nsec
  process_subtest:PASS:specs_alloc 0 nsec
  run_subtest:PASS:obj_open_mem 0 nsec
  run_subtest:FAIL:unexpected_load_success unexpected success: 0
  #465/1   verifier_const/rodata: write rejected:FAIL
  #465/2   verifier_const/bss: write accepted:OK
  #465/3   verifier_const/data: write accepted:OK
  #465     verifier_const:FAIL
  [...]

After fix:

  # ./vmtest.sh -- ./test_progs -t verifier_const
  [...]
  ./test_progs -t verifier_const
  #465/1   verifier_const/rodata: write rejected:OK
  #465/2   verifier_const/bss: write accepted:OK
  #465/3   verifier_const/data: write accepted:OK
  #465     verifier_const:OK
  [...]

Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarShung-Hsi Yu <shung-hsi.yu@suse.com>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240913191754.13290-8-daniel@iogearbox.net


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent b073b82d

tools/testing/selftests/bpf/prog_tests/verifier.c

+2 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include "verifier_cgroup_inv_retcode.skel.h"

#include "verifier_cgroup_skb.skel.h"

#include "verifier_cgroup_storage.skel.h"

#include "verifier_const.skel.h"

#include "verifier_const_or.skel.h"

#include "verifier_ctx.skel.h"

#include "verifier_ctx_sk_msg.skel.h"
@@ -146,6 +147,7 @@ void test_verifier_cfg(void) { RUN(verifier_cfg); } 
void test_verifier_cgroup_inv_retcode(void)   { RUN(verifier_cgroup_inv_retcode); }

void test_verifier_cgroup_skb(void)           { RUN(verifier_cgroup_skb); }

void test_verifier_cgroup_storage(void)       { RUN(verifier_cgroup_storage); }

void test_verifier_const(void)                { RUN(verifier_const); }

void test_verifier_const_or(void)             { RUN(verifier_const_or); }

void test_verifier_ctx(void)                  { RUN(verifier_ctx); }

void test_verifier_ctx_sk_msg(void)           { RUN(verifier_ctx_sk_msg); }

tools/testing/selftests/bpf/progs/verifier_const.c

0 → 100644
+42 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Copyright (c) 2024 Isovalent */



#include <linux/bpf.h>

#include <bpf/bpf_helpers.h>

#include "bpf_misc.h"



const volatile long foo = 42;

long bar;

long bart = 96;



SEC("tc/ingress")

__description("rodata: write rejected")

__failure __msg("write into map forbidden")

int tcx1(struct __sk_buff *skb)

{

	char buff[] = { '8', '4', '\0' };

	bpf_strtol(buff, sizeof(buff), 0, (long *)&foo);

	return TCX_PASS;

}



SEC("tc/ingress")

__description("bss: write accepted")

__success

int tcx2(struct __sk_buff *skb)

{

	char buff[] = { '8', '4', '\0' };

	bpf_strtol(buff, sizeof(buff), 0, &bar);

	return TCX_PASS;

}



SEC("tc/ingress")

__description("data: write accepted")

__success

int tcx3(struct __sk_buff *skb)

{

	char buff[] = { '8', '4', '\0' };

	bpf_strtol(buff, sizeof(buff), 0, &bart);

	return TCX_PASS;

}



char LICENSE[] SEC("license") = "GPL";