selftests/bpf: Add a test for ptr_to_map_value on stack for helper access

Change bpf_iter_task.c such that pointer to map_value may appear
on the stack for bpf_seq_printf() to access. Without previous
verifier patch, the bpf_iter test will fail.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201210013350.943985-1-yhs@fb.com
This commit is contained in:
Yonghong Song 2020-12-09 17:33:50 -08:00 committed by Daniel Borkmann
parent cd17d38f8b
commit b4b638c36b
2 changed files with 5 additions and 3 deletions

View File

@ -11,9 +11,10 @@ int dump_task(struct bpf_iter__task *ctx)
{
struct seq_file *seq = ctx->meta->seq;
struct task_struct *task = ctx->task;
static char info[] = " === END ===";
if (task == (void *)0) {
BPF_SEQ_PRINTF(seq, " === END ===\n");
BPF_SEQ_PRINTF(seq, "%s\n", info);
return 0;
}

View File

@ -108,8 +108,9 @@
BPF_EXIT_INSN(),
},
.fixup_map_hash_8b = { 3 },
.errstr = "invalid indirect read from stack off -8+0 size 8",
.result = REJECT,
.errstr_unpriv = "invalid indirect read from stack off -8+0 size 8",
.result_unpriv = REJECT,
.result = ACCEPT,
},
{
"unpriv: mangle pointer on stack 1",