Daniel Borkmann says:

====================
bpf-next 2022-11-25

We've added 101 non-merge commits during the last 11 day(s) which contain
a total of 109 files changed, 8827 insertions(+), 1129 deletions(-).

The main changes are:

1) Support for user defined BPF objects: the use case is to allocate own
   objects, build own object hierarchies and use the building blocks to
   build own data structures flexibly, for example, linked lists in BPF,
   from Kumar Kartikeya Dwivedi.

2) Add bpf_rcu_read_{,un}lock() support for sleepable programs,
   from Yonghong Song.

3) Add support storing struct task_struct objects as kptrs in maps,
   from David Vernet.

4) Batch of BPF map documentation improvements, from Maryam Tahhan
   and Donald Hunter.

5) Improve BPF verifier to propagate nullness information for branches
   of register to register comparisons, from Eduard Zingerman.

6) Fix cgroup BPF iter infra to hold reference on the start cgroup,
   from Hou Tao.

7) Fix BPF verifier to not mark fentry/fexit program arguments as trusted
   given it is not the case for them, from Alexei Starovoitov.

8) Improve BPF verifier's realloc handling to better play along with dynamic
   runtime analysis tools like KASAN and friends, from Kees Cook.

9) Remove legacy libbpf mode support from bpftool,
   from Sahid Orentino Ferdjaoui.

10) Rework zero-len skb redirection checks to avoid potentially breaking
    existing BPF test infra users, from Stanislav Fomichev.

11) Two small refactorings which are independent and have been split out
    of the XDP queueing RFC series, from Toke Høiland-Jørgensen.

12) Fix a memory leak in LSM cgroup BPF selftest, from Wang Yufen.

13) Documentation on how to run BPF CI without patch submission,
    from Daniel Müller.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
====================

Link: https://lore.kernel.org/r/20221125012450.441-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 260 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/progs/cgrp_kfunc_failure.c b/tools/testing/selftests/bpf/progs/cgrp_kfunc_failure.c
new file mode 100644
index 000000000000..a1369b5ebcf8
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/cgrp_kfunc_failure.c
@@ -0,0 +1,260 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
+
+#include <vmlinux.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_helpers.h>
+
+#include "cgrp_kfunc_common.h"
+
+char _license[] SEC("license") = "GPL";
+
+/* Prototype for all of the program trace events below:
+ *
+ * TRACE_EVENT(cgroup_mkdir,
+ *         TP_PROTO(struct cgroup *cgrp, const char *path),
+ *         TP_ARGS(cgrp, path)
+ */
+
+static struct __cgrps_kfunc_map_value *insert_lookup_cgrp(struct cgroup *cgrp)
+{
+	int status;
+
+	status = cgrps_kfunc_map_insert(cgrp);
+	if (status)
+		return NULL;
+
+	return cgrps_kfunc_map_value_lookup(cgrp);
+}
+
+SEC("tp_btf/cgroup_mkdir")
+int BPF_PROG(cgrp_kfunc_acquire_untrusted, struct cgroup *cgrp, const char *path)
+{
+	struct cgroup *acquired;
+	struct __cgrps_kfunc_map_value *v;
+
+	v = insert_lookup_cgrp(cgrp);
+	if (!v)
+		return 0;
+
+	/* Can't invoke bpf_cgroup_acquire() on an untrusted pointer. */
+	acquired = bpf_cgroup_acquire(v->cgrp);
+	bpf_cgroup_release(acquired);
+
+	return 0;
+}
+
+SEC("tp_btf/cgroup_mkdir")
+int BPF_PROG(cgrp_kfunc_acquire_fp, struct cgroup *cgrp, const char *path)
+{
+	struct cgroup *acquired, *stack_cgrp = (struct cgroup *)&path;
+
+	/* Can't invoke bpf_cgroup_acquire() on a random frame pointer. */
+	acquired = bpf_cgroup_acquire((struct cgroup *)&stack_cgrp);
+	bpf_cgroup_release(acquired);
+
+	return 0;
+}
+
+SEC("kretprobe/cgroup_destroy_locked")
+int BPF_PROG(cgrp_kfunc_acquire_unsafe_kretprobe, struct cgroup *cgrp)
+{
+	struct cgroup *acquired;
+
+	/* Can't acquire an untrusted struct cgroup * pointer. */
+	acquired = bpf_cgroup_acquire(cgrp);
+	bpf_cgroup_release(acquired);
+
+	return 0;
+}
+
+SEC("tp_btf/cgroup_mkdir")
+int BPF_PROG(cgrp_kfunc_acquire_trusted_walked, struct cgroup *cgrp, const char *path)
+{
+	struct cgroup *acquired;
+
+	/* Can't invoke bpf_cgroup_acquire() on a pointer obtained from walking a trusted cgroup. */
+	acquired = bpf_cgroup_acquire(cgrp->old_dom_cgrp);
+	bpf_cgroup_release(acquired);
+
+	return 0;
+}
+
+
+SEC("tp_btf/cgroup_mkdir")
+int BPF_PROG(cgrp_kfunc_acquire_null, struct cgroup *cgrp, const char *path)
+{
+	struct cgroup *acquired;
+
+	/* Can't invoke bpf_cgroup_acquire() on a NULL pointer. */
+	acquired = bpf_cgroup_acquire(NULL);
+	if (!acquired)
+		return 0;
+	bpf_cgroup_release(acquired);
+
+	return 0;
+}
+
+SEC("tp_btf/cgroup_mkdir")
+int BPF_PROG(cgrp_kfunc_acquire_unreleased, struct cgroup *cgrp, const char *path)
+{
+	struct cgroup *acquired;
+
+	acquired = bpf_cgroup_acquire(cgrp);
+
+	/* Acquired cgroup is never released. */
+
+	return 0;
+}
+
+SEC("tp_btf/cgroup_mkdir")
+int BPF_PROG(cgrp_kfunc_get_non_kptr_param, struct cgroup *cgrp, const char *path)
+{
+	struct cgroup *kptr;
+
+	/* Cannot use bpf_cgroup_kptr_get() on a non-kptr, even on a valid cgroup. */
+	kptr = bpf_cgroup_kptr_get(&cgrp);
+	if (!kptr)
+		return 0;
+
+	bpf_cgroup_release(kptr);
+
+	return 0;
+}
+
+SEC("tp_btf/cgroup_mkdir")
+int BPF_PROG(cgrp_kfunc_get_non_kptr_acquired, struct cgroup *cgrp, const char *path)
+{
+	struct cgroup *kptr, *acquired;
+
+	acquired = bpf_cgroup_acquire(cgrp);
+
+	/* Cannot use bpf_cgroup_kptr_get() on a non-map-value, even if the kptr was acquired. */
+	kptr = bpf_cgroup_kptr_get(&acquired);
+	bpf_cgroup_release(acquired);
+	if (!kptr)
+		return 0;
+
+	bpf_cgroup_release(kptr);
+
+	return 0;
+}
+
+SEC("tp_btf/cgroup_mkdir")
+int BPF_PROG(cgrp_kfunc_get_null, struct cgroup *cgrp, const char *path)
+{
+	struct cgroup *kptr;
+
+	/* Cannot use bpf_cgroup_kptr_get() on a NULL pointer. */
+	kptr = bpf_cgroup_kptr_get(NULL);
+	if (!kptr)
+		return 0;
+
+	bpf_cgroup_release(kptr);
+
+	return 0;
+}
+
+SEC("tp_btf/cgroup_mkdir")
+int BPF_PROG(cgrp_kfunc_xchg_unreleased, struct cgroup *cgrp, const char *path)
+{
+	struct cgroup *kptr;
+	struct __cgrps_kfunc_map_value *v;
+
+	v = insert_lookup_cgrp(cgrp);
+	if (!v)
+		return 0;
+
+	kptr = bpf_kptr_xchg(&v->cgrp, NULL);
+	if (!kptr)
+		return 0;
+
+	/* Kptr retrieved from map is never released. */
+
+	return 0;
+}
+
+SEC("tp_btf/cgroup_mkdir")
+int BPF_PROG(cgrp_kfunc_get_unreleased, struct cgroup *cgrp, const char *path)
+{
+	struct cgroup *kptr;
+	struct __cgrps_kfunc_map_value *v;
+
+	v = insert_lookup_cgrp(cgrp);
+	if (!v)
+		return 0;
+
+	kptr = bpf_cgroup_kptr_get(&v->cgrp);
+	if (!kptr)
+		return 0;
+
+	/* Kptr acquired above is never released. */
+
+	return 0;
+}
+
+SEC("tp_btf/cgroup_mkdir")
+int BPF_PROG(cgrp_kfunc_release_untrusted, struct cgroup *cgrp, const char *path)
+{
+	struct __cgrps_kfunc_map_value *v;
+
+	v = insert_lookup_cgrp(cgrp);
+	if (!v)
+		return 0;
+
+	/* Can't invoke bpf_cgroup_release() on an untrusted pointer. */
+	bpf_cgroup_release(v->cgrp);
+
+	return 0;
+}
+
+SEC("tp_btf/cgroup_mkdir")
+int BPF_PROG(cgrp_kfunc_release_fp, struct cgroup *cgrp, const char *path)
+{
+	struct cgroup *acquired = (struct cgroup *)&path;
+
+	/* Cannot release random frame pointer. */
+	bpf_cgroup_release(acquired);
+
+	return 0;
+}
+
+SEC("tp_btf/cgroup_mkdir")
+int BPF_PROG(cgrp_kfunc_release_null, struct cgroup *cgrp, const char *path)
+{
+	struct __cgrps_kfunc_map_value local, *v;
+	long status;
+	struct cgroup *acquired, *old;
+	s32 id;
+
+	status = bpf_probe_read_kernel(&id, sizeof(id), &cgrp->self.id);
+	if (status)
+		return 0;
+
+	local.cgrp = NULL;
+	status = bpf_map_update_elem(&__cgrps_kfunc_map, &id, &local, BPF_NOEXIST);
+	if (status)
+		return status;
+
+	v = bpf_map_lookup_elem(&__cgrps_kfunc_map, &id);
+	if (!v)
+		return -ENOENT;
+
+	acquired = bpf_cgroup_acquire(cgrp);
+
+	old = bpf_kptr_xchg(&v->cgrp, acquired);
+
+	/* old cannot be passed to bpf_cgroup_release() without a NULL check. */
+	bpf_cgroup_release(old);
+
+	return 0;
+}
+
+SEC("tp_btf/cgroup_mkdir")
+int BPF_PROG(cgrp_kfunc_release_unacquired, struct cgroup *cgrp, const char *path)
+{
+	/* Cannot release trusted cgroup pointer which was not acquired. */
+	bpf_cgroup_release(cgrp);
+
+	return 0;
+}