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, 42 insertions, 0 deletions

diff --git a/fs/adfs/dir_fplus.h b/fs/adfs/dir_fplus.h
new file mode 100644
index 000000000..d729b1591
--- /dev/null
+++ b/fs/adfs/dir_fplus.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ *  linux/fs/adfs/dir_fplus.h
+ *
+ *  Copyright (C) 1999 Russell King
+ *
+ *  Structures of directories on the F+ format disk
+ */
+
+#define ADFS_FPLUS_NAME_LEN	255
+
+#define BIGDIRSTARTNAME ('S' | 'B' << 8 | 'P' << 16 | 'r' << 24)
+#define BIGDIRENDNAME	('o' | 'v' << 8 | 'e' << 16 | 'n' << 24)
+
+struct adfs_bigdirheader {
+	__u8	startmasseq;
+	__u8	bigdirversion[3];
+	__le32	bigdirstartname;
+	__le32	bigdirnamelen;
+	__le32	bigdirsize;
+	__le32	bigdirentries;
+	__le32	bigdirnamesize;
+	__le32	bigdirparent;
+	char	bigdirname[1];
+} __attribute__((packed, aligned(4)));
+
+struct adfs_bigdirentry {
+	__le32	bigdirload;
+	__le32	bigdirexec;
+	__le32	bigdirlen;
+	__le32	bigdirindaddr;
+	__le32	bigdirattr;
+	__le32	bigdirobnamelen;
+	__le32	bigdirobnameptr;
+} __attribute__((packed, aligned(4)));
+
+struct adfs_bigdirtail {
+	__le32	bigdirendname;
+	__u8	bigdirendmasseq;
+	__u8	reserved[2];
+	__u8	bigdircheckbyte;
+} __attribute__((packed, aligned(4)));