bpf: mark a NULL kfunc argument precisegrafted

check_kfunc_arg() allows bpf_register_is_null() for nullable arguments
w/o marking the underlying scalar register precise. Hence a checkpoint
created on such a path would prune against arbitrary scalar value.

Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 65 insertions, 0 deletions

diff --git a/drivers/android/Kconfig b/drivers/android/Kconfig
new file mode 100644
index 000000000..e2e402c9d
--- /dev/null
+++ b/drivers/android/Kconfig
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: GPL-2.0
+menu "Android"
+
+config ANDROID_BINDER_IPC
+	bool "Android Binder IPC Driver"
+	depends on MMU
+	depends on NET
+	default n
+	help
+	  Binder is used in Android for both communication between processes,
+	  and remote method invocation.
+
+	  This means one Android process can call a method/routine in another
+	  Android process, using Binder to identify, invoke and pass arguments
+	  between said processes.
+
+config ANDROID_BINDER_IPC_RUST
+	bool "Rust version of Android Binder IPC Driver"
+	depends on RUST && MMU && !ANDROID_BINDER_IPC
+	help
+	  This enables the Rust implementation of the Binder driver.
+
+	  Binder is used in Android for both communication between processes,
+	  and remote method invocation.
+
+	  This means one Android process can call a method/routine in another
+	  Android process, using Binder to identify, invoke and pass arguments
+	  between said processes.
+
+config ANDROID_BINDERFS
+	bool "Android Binderfs filesystem"
+	depends on ANDROID_BINDER_IPC
+	default n
+	help
+	  Binderfs is a pseudo-filesystem for the Android Binder IPC driver
+	  which can be mounted per-ipc namespace allowing to run multiple
+	  instances of Android.
+	  Each binderfs mount initially only contains a binder-control device.
+	  It can be used to dynamically allocate new binder IPC devices via
+	  ioctls.
+
+config ANDROID_BINDER_DEVICES
+	string "Android Binder devices"
+	depends on ANDROID_BINDER_IPC || ANDROID_BINDER_IPC_RUST
+	default "binder,hwbinder,vndbinder"
+	help
+	  Default value for the binder.devices parameter.
+
+	  The binder.devices parameter is a comma-separated list of strings
+	  that specifies the names of the binder device nodes that will be
+	  created. Each binder device has its own context manager, and is
+	  therefore logically separated from the other devices.
+
+config ANDROID_BINDER_ALLOC_KUNIT_TEST
+	tristate "KUnit Tests for Android Binder Alloc" if !KUNIT_ALL_TESTS
+	depends on ANDROID_BINDER_IPC && KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This feature builds the binder alloc KUnit tests.
+
+	  Each test case runs using a pared-down binder_alloc struct and
+	  test-specific freelist, which allows this KUnit module to be loaded
+	  for testing without interfering with a running system.
+
+endmenu