selftests/bpf: Reject graph kptr use after RCU unlockgrafted

Add a sleepable verifier test that loads a graph-node local kptr in an
explicit RCU read-side critical section, then passes its node to
bpf_rbtree_remove() after the section ends.

Before the verifier fix, the stale NON_OWN_REF flag makes the node look like
a live borrowed reference and the program is accepted. After the fix, the
pointer is demoted without NON_OWN_REF and the graph kfunc argument is
rejected.

Also exercise a graph kptr loaded while a spin lock provides implicit RCU
protection. The pointer must be invalidated when the lock is released, which
guards the required ordering between non-owning-reference invalidation and
RCU demotion.

Update the existing fault-protected load test state description. The
post-unlock pointer no longer carries NON_OWN_REF, but remains readable
because the load is rewritten to use BPF_PROBE_MEM.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 26 insertions, 0 deletions

diff --git a/Documentation/networking/ioam6-sysctl.rst b/Documentation/networking/ioam6-sysctl.rst
new file mode 100644
index 000000000..c18cab2c4
--- /dev/null
+++ b/Documentation/networking/ioam6-sysctl.rst
@@ -0,0 +1,26 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=====================
+IOAM6 Sysfs variables
+=====================
+
+
+/proc/sys/net/conf/<iface>/ioam6_* variables:
+=============================================
+
+ioam6_enabled - BOOL
+        Accept (= enabled) or ignore (= disabled) IPv6 IOAM options on ingress
+        for this interface.
+
+        * 0 - disabled (default)
+        * 1 - enabled
+
+ioam6_id - SHORT INTEGER
+        Define the IOAM id of this interface.
+
+        Default is ~0.
+
+ioam6_id_wide - INTEGER
+        Define the wide IOAM id of this interface.
+
+        Default is ~0.