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, 49 insertions, 0 deletions

diff --git a/net/atm/resources.h b/net/atm/resources.h
new file mode 100644
index 000000000..4a0839e92
--- /dev/null
+++ b/net/atm/resources.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* net/atm/resources.h - ATM-related resources */
+
+/* Written 1995-1998 by Werner Almesberger, EPFL LRC/ICA */
+
+
+#ifndef NET_ATM_RESOURCES_H
+#define NET_ATM_RESOURCES_H
+
+#include <linux/atmdev.h>
+#include <linux/mutex.h>
+
+
+extern struct list_head atm_devs;
+extern struct mutex atm_dev_mutex;
+
+int atm_getnames(void __user *buf, int __user *iobuf_len);
+int atm_dev_ioctl(unsigned int cmd, void __user *buf, int __user *sioc_len,
+		  int number, int compat);
+
+#ifdef CONFIG_PROC_FS
+
+#include <linux/proc_fs.h>
+
+void *atm_dev_seq_start(struct seq_file *seq, loff_t *pos);
+void atm_dev_seq_stop(struct seq_file *seq, void *v);
+void *atm_dev_seq_next(struct seq_file *seq, void *v, loff_t *pos);
+
+
+int atm_proc_dev_register(struct atm_dev *dev);
+void atm_proc_dev_deregister(struct atm_dev *dev);
+
+#else
+
+static inline int atm_proc_dev_register(struct atm_dev *dev)
+{
+	return 0;
+}
+
+static inline void atm_proc_dev_deregister(struct atm_dev *dev)
+{
+	/* nothing */
+}
+
+#endif /* CONFIG_PROC_FS */
+
+int atm_register_sysfs(struct atm_dev *adev, struct device *parent);
+void atm_unregister_sysfs(struct atm_dev *adev);
+#endif