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, 61 insertions, 0 deletions

diff --git a/fs/adfs/dir_f.h b/fs/adfs/dir_f.h
new file mode 100644
index 000000000..4e6c53d59
--- /dev/null
+++ b/fs/adfs/dir_f.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ *  linux/fs/adfs/dir_f.h
+ *
+ *  Copyright (C) 1999 Russell King
+ *
+ *  Structures of directories on the F format disk
+ */
+#ifndef ADFS_DIR_F_H
+#define ADFS_DIR_F_H
+
+/*
+ * Directory header
+ */
+struct adfs_dirheader {
+	__u8 startmasseq;
+	__u8 startname[4];
+} __attribute__((packed));
+
+#define ADFS_NEWDIR_SIZE	2048
+#define ADFS_NUM_DIR_ENTRIES	77
+
+/*
+ * Directory entries
+ */
+struct adfs_direntry {
+#define ADFS_F_NAME_LEN 10
+	char dirobname[ADFS_F_NAME_LEN];
+	__u8 dirload[4];
+	__u8 direxec[4];
+	__u8 dirlen[4];
+	__u8 dirinddiscadd[3];
+	__u8 newdiratts;
+} __attribute__((packed));
+
+/*
+ * Directory tail
+ */
+struct adfs_olddirtail {
+	__u8 dirlastmask;
+	char dirname[10];
+	__u8 dirparent[3];
+	char dirtitle[19];
+	__u8 reserved[14];
+	__u8 endmasseq;
+	__u8 endname[4];
+	__u8 dircheckbyte;
+} __attribute__((packed));
+
+struct adfs_newdirtail {
+	__u8 dirlastmask;
+	__u8 reserved[2];
+	__u8 dirparent[3];
+	char dirtitle[19];
+	char dirname[10];
+	__u8 endmasseq;
+	__u8 endname[4];
+	__u8 dircheckbyte;
+} __attribute__((packed));
+
+#endif