This is a note to let you know that I've just added the patch titled
bpf/selftests: Test PTR_TO_RDONLY_MEM
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bpf-selftests-test-ptr_to_rdonly_mem.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Fri Apr 29 11:02:06 AM CEST 2022
From: Hao Luo <haoluo@xxxxxxxxxx>
Date: Thu, 28 Apr 2022 16:57:50 -0700
Subject: bpf/selftests: Test PTR_TO_RDONLY_MEM
To: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>, Andrii Nakryiko <andrii@xxxxxxxxxx>, Daniel Borkmann <daniel@xxxxxxxxxxxxx>, laura@xxxxxxxxxxxx, Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>, stable@xxxxxxxxxxxxxxx, Hao Luo <haoluo@xxxxxxxxxx>
Message-ID: <20220428235751.103203-10-haoluo@xxxxxxxxxx>
From: Hao Luo <haoluo@xxxxxxxxxx>
commit 9497c458c10b049438ef6e6ddda898edbc3ec6a8 upstream.
This test verifies that a ksym of non-struct can not be directly
updated.
Signed-off-by: Hao Luo <haoluo@xxxxxxxxxx>
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20211217003152.48334-10-haoluo@xxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx # 5.15.x
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/bpf/prog_tests/ksyms_btf.c | 14 ++++
tools/testing/selftests/bpf/progs/test_ksyms_btf_write_check.c | 29 ++++++++++
2 files changed, 43 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/test_ksyms_btf_write_check.c
--- a/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c
@@ -7,6 +7,7 @@
#include "test_ksyms_btf.skel.h"
#include "test_ksyms_btf_null_check.skel.h"
#include "test_ksyms_weak.skel.h"
+#include "test_ksyms_btf_write_check.skel.h"
static int duration;
@@ -109,6 +110,16 @@ cleanup:
test_ksyms_weak__destroy(skel);
}
+static void test_write_check(void)
+{
+ struct test_ksyms_btf_write_check *skel;
+
+ skel = test_ksyms_btf_write_check__open_and_load();
+ ASSERT_ERR_PTR(skel, "unexpected load of a prog writing to ksym memory\n");
+
+ test_ksyms_btf_write_check__destroy(skel);
+}
+
void test_ksyms_btf(void)
{
int percpu_datasec;
@@ -136,4 +147,7 @@ void test_ksyms_btf(void)
if (test__start_subtest("weak_ksyms"))
test_weak_syms();
+
+ if (test__start_subtest("write_check"))
+ test_write_check();
}
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_ksyms_btf_write_check.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Google */
+
+#include "vmlinux.h"
+
+#include <bpf/bpf_helpers.h>
+
+extern const int bpf_prog_active __ksym; /* int type global var. */
+
+SEC("raw_tp/sys_enter")
+int handler(const void *ctx)
+{
+ int *active;
+ __u32 cpu;
+
+ cpu = bpf_get_smp_processor_id();
+ active = (int *)bpf_per_cpu_ptr(&bpf_prog_active, cpu);
+ if (active) {
+ /* Kernel memory obtained from bpf_{per,this}_cpu_ptr
+ * is read-only, should _not_ pass verification.
+ */
+ /* WRITE_ONCE */
+ *(volatile int *)active = -1;
+ }
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
Patches currently in stable-queue which might be from haoluo@xxxxxxxxxx are
queue-5.15/bpf-replace-ret_xxx_or_null-with-ret_xxx-ptr_maybe_null.patch
queue-5.15/bpf-introduce-mem_rdonly-flag.patch
queue-5.15/bpf-make-per_cpu_ptr-return-rdonly-ptr_to_mem.patch
queue-5.15/bpf-introduce-composable-reg-ret-and-arg-types.patch
queue-5.15/bpf-add-mem_rdonly-for-helper-args-that-are-pointers-to-rdonly-mem.patch
queue-5.15/bpf-replace-arg_xxx_or_null-with-arg_xxx-ptr_maybe_null.patch
queue-5.15/bpf-replace-ptr_to_xxx_or_null-with-ptr_to_xxx-ptr_maybe_null.patch
queue-5.15/bpf-fix-crash-due-to-out-of-bounds-access-into-reg2btf_ids.patch
queue-5.15/bpf-convert-ptr_to_mem_or_null-to-composable-types.patch
queue-5.15/bpf-selftests-test-ptr_to_rdonly_mem.patch
