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, 38 insertions, 0 deletions

diff --git a/drivers/scsi/scsi_sysctl.c b/drivers/scsi/scsi_sysctl.c
new file mode 100644
index 000000000..055a03a83
--- /dev/null
+++ b/drivers/scsi/scsi_sysctl.c
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2003 Christoph Hellwig.
+ */
+
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sysctl.h>
+
+#include "scsi_logging.h"
+#include "scsi_priv.h"
+
+
+static const struct ctl_table scsi_table[] = {
+	{ .procname	= "logging_level",
+	  .data		= &scsi_logging_level,
+	  .maxlen	= sizeof(scsi_logging_level),
+	  .mode		= 0644,
+	  .proc_handler	= proc_dointvec_minmax,
+	  .extra1	= SYSCTL_ZERO,
+	  .extra2	= SYSCTL_INT_MAX },
+};
+
+static struct ctl_table_header *scsi_table_header;
+
+int __init scsi_init_sysctl(void)
+{
+	scsi_table_header = register_sysctl("dev/scsi", scsi_table);
+	if (!scsi_table_header)
+		return -ENOMEM;
+	return 0;
+}
+
+void scsi_exit_sysctl(void)
+{
+	unregister_sysctl_table(scsi_table_header);
+}