Ensure that when CAP_PERFMON is dropped, and the verifier sees
allow_ptr_leaks as false, we are not permitted to read from a
STACK_INVALID slot. Without the fix, the test will report unexpected
success in loading.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
---
.../selftests/bpf/progs/verifier_spill_fill.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/tools/testing/selftests/bpf/progs/verifier_spill_fill.c b/tools/testing/selftests/bpf/progs/verifier_spill_fill.c
index 671d9f415dbf..bab6d789ba00 100644
--- a/tools/testing/selftests/bpf/progs/verifier_spill_fill.c
+++ b/tools/testing/selftests/bpf/progs/verifier_spill_fill.c
@@ -1244,4 +1244,22 @@ __naked void old_stack_misc_vs_cur_ctx_ptr(void)
: __clobber_all);
}
+SEC("socket")
+__description("stack_noperfmon: reject read of invalid slots")
+__success
+__caps_unpriv(CAP_BPF)
+__failure_unpriv __msg_unpriv("invalid read from stack off -8+1 size 8")
+__naked void stack_noperfmon_reject_invalid_read(void)
+{
+ asm volatile (" \
+ r2 = 1; \
+ r6 = r10; \
+ r6 += -8; \
+ *(u8 *)(r6 + 0) = r2; \
+ r2 = *(u64 *)(r6 + 0); \
+ r0 = 0; \
+ exit; \
+" ::: __clobber_all);
+}
+
char _license[] SEC("license") = "GPL";
--
2.43.5
