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, 53 insertions, 0 deletions

diff --git a/drivers/leds/trigger/ledtrig-camera.c b/drivers/leds/trigger/ledtrig-camera.c
new file mode 100644
index 000000000..ab1c41087
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-camera.c
@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Camera Flash and Torch On/Off Trigger
+ *
+ * based on ledtrig-ide-disk.c
+ *
+ * Copyright 2013 Texas Instruments
+ *
+ * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/leds.h>
+
+DEFINE_LED_TRIGGER(ledtrig_flash);
+DEFINE_LED_TRIGGER(ledtrig_torch);
+
+void ledtrig_flash_ctrl(bool on)
+{
+	enum led_brightness brt = on ? LED_FULL : LED_OFF;
+
+	led_trigger_event(ledtrig_flash, brt);
+}
+EXPORT_SYMBOL_GPL(ledtrig_flash_ctrl);
+
+void ledtrig_torch_ctrl(bool on)
+{
+	enum led_brightness brt = on ? LED_FULL : LED_OFF;
+
+	led_trigger_event(ledtrig_torch, brt);
+}
+EXPORT_SYMBOL_GPL(ledtrig_torch_ctrl);
+
+static int __init ledtrig_camera_init(void)
+{
+	led_trigger_register_simple("flash", &ledtrig_flash);
+	led_trigger_register_simple("torch", &ledtrig_torch);
+	return 0;
+}
+module_init(ledtrig_camera_init);
+
+static void __exit ledtrig_camera_exit(void)
+{
+	led_trigger_unregister_simple(ledtrig_torch);
+	led_trigger_unregister_simple(ledtrig_flash);
+}
+module_exit(ledtrig_camera_exit);
+
+MODULE_DESCRIPTION("LED Trigger for Camera Flash/Torch Control");
+MODULE_AUTHOR("Milo Kim");
+MODULE_LICENSE("GPL v2");