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, 36 insertions, 0 deletions

diff --git a/drivers/firmware/google/memconsole.h b/drivers/firmware/google/memconsole.h
new file mode 100644
index 000000000..aaff2b72b
--- /dev/null
+++ b/drivers/firmware/google/memconsole.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * memconsole.h
+ *
+ * Internal headers of the memory based BIOS console.
+ *
+ * Copyright 2017 Google Inc.
+ */
+
+#ifndef __FIRMWARE_GOOGLE_MEMCONSOLE_H
+#define __FIRMWARE_GOOGLE_MEMCONSOLE_H
+
+#include <linux/types.h>
+
+/*
+ * memconsole_setup
+ *
+ * Initialize the memory console, passing the function to handle read accesses.
+ */
+void memconsole_setup(ssize_t (*read_func)(char *, loff_t, size_t));
+
+/*
+ * memconsole_sysfs_init
+ *
+ * Update memory console length and create binary file
+ * for firmware object.
+ */
+int memconsole_sysfs_init(void);
+
+/* memconsole_exit
+ *
+ * Unmap the console buffer.
+ */
+void memconsole_exit(void);
+
+#endif /* __FIRMWARE_GOOGLE_MEMCONSOLE_H */