From 836b2fe544a5e9b5ce116622cb36fba33838c6fd Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 01:33:23 -0700 Subject: selftests/bpf: Check that JMP32 pointer vs zero jumps are not predicted Add jmp32_ptr_vs_zero_jne: the fall-through of the 32-bit compare, which the verifier used to skip, contains an out of bounds map value access, hence w/o the previous patch the program is accepted. See previous patch for detailed description. Reported-by: Nicholas Carlini Suggested-by: Nicholas Carlini Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/bpf/20260904083325.2083493-6-eddyz87@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi --- samples/bpf/tracex1_user.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 samples/bpf/tracex1_user.c (limited to 'samples/bpf/tracex1_user.c') diff --git a/samples/bpf/tracex1_user.c b/samples/bpf/tracex1_user.c new file mode 100644 index 000000000..8c3d9043a --- /dev/null +++ b/samples/bpf/tracex1_user.c @@ -0,0 +1,50 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include "trace_helpers.h" + +int main(int ac, char **argv) +{ + struct bpf_link *link = NULL; + struct bpf_program *prog; + struct bpf_object *obj; + char filename[256]; + FILE *f; + + snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]); + obj = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + return 0; + } + + prog = bpf_object__find_program_by_name(obj, "bpf_prog1"); + if (!prog) { + fprintf(stderr, "ERROR: finding a prog in obj file failed\n"); + goto cleanup; + } + + /* load BPF program */ + if (bpf_object__load(obj)) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + goto cleanup; + } + + link = bpf_program__attach(prog); + if (libbpf_get_error(link)) { + fprintf(stderr, "ERROR: bpf_program__attach failed\n"); + link = NULL; + goto cleanup; + } + + f = popen("taskset 1 ping -c5 localhost", "r"); + (void) f; + + read_trace_pipe(); + +cleanup: + bpf_link__destroy(link); + bpf_object__close(obj); + return 0; +} -- cgit v1.3.1