selftests/bpf: Test packet range of pointers sharing an idgrafted

Add tests where two packet pointers share an id and tightening one
pointer's umax from its var_off would put it less than their constant
distance from the other's umax: with an index & 0x38 capped at 50, the
base pointer keeps umax 50, so the pointer 8 bytes further on must keep
umax 58, even though its known bits allow at most 56.

These refused a valid program or accepted an out-of-bounds access before
the fix:

- check the advanced copy, load through the base: valid, was refused;
- check the base, load the byte at base + 1 through a copy advanced by
  8: was accepted;
- check base + 4, load 4 bytes at base + 2 through base + 8: reads two
  bytes past the checked range, was accepted;
- the same as the second with data_meta pointers checked against data:
  was accepted.

These pass with and without the fix and cover nearby paths:

- subtract an unknown scalar from a checked pointer and load below it
  (the range is kept across a new id);
- reach a load through two paths whose checks cover 8 and 7 bytes after
  the loaded pointer; the second path must not be pruned by the first;
- spill a copy of a pointer, check the pointer, fill the copy and load
  one byte past the checked range: the load is refused, and the copy
  has the range of the check.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20261001145255.855630-2-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

1 files changed, 49 insertions, 0 deletions

diff --git a/include/crypto/aes-ecb.h b/include/crypto/aes-ecb.h
new file mode 100644
index 000000000..8cac1f879
--- /dev/null
+++ b/include/crypto/aes-ecb.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * AES-ECB unauthenticated encryption and decryption
+ *
+ * Copyright 2026 Google LLC
+ */
+#ifndef _CRYPTO_AES_ECB_H
+#define _CRYPTO_AES_ECB_H
+
+#include <crypto/aes.h>
+
+/**
+ * aes_ecb_encrypt() - Encrypt data using AES-ECB
+ * @dst: The destination buffer.  Can be in-place or out-of-place.  For other
+ *	 overlaps the behavior is unspecified.
+ * @src: The source data
+ * @len: Number of bytes to encrypt.  Must be a multiple of AES_BLOCK_SIZE.
+ * @key: The key, already prepared using aes_preparekey() or aes_prepareenckey()
+ *
+ * ECB mode is insecure by itself.  This function exists only for compatibility
+ * with legacy protocols and for internal use by other modes.
+ *
+ * This supports incremental encryption, but the length of each chunk must be a
+ * multiple of AES_BLOCK_SIZE.
+ *
+ * Context: Any context.
+ */
+void aes_ecb_encrypt(u8 *dst, const u8 *src, size_t len, aes_encrypt_arg key);
+
+/**
+ * aes_ecb_decrypt() - Decrypt data using AES-ECB
+ * @dst: The destination buffer.  Can be in-place or out-of-place.  For other
+ *	 overlaps the behavior is unspecified.
+ * @src: The source data
+ * @len: Number of bytes to decrypt.  Must be a multiple of AES_BLOCK_SIZE.
+ * @key: The key, already prepared using aes_preparekey()
+ *
+ * ECB mode is insecure by itself.  This function exists only for compatibility
+ * with legacy protocols and for internal use by other modes.
+ *
+ * This supports incremental decryption, but the length of each chunk must be a
+ * multiple of AES_BLOCK_SIZE.
+ *
+ * Context: Any context.
+ */
+void aes_ecb_decrypt(u8 *dst, const u8 *src, size_t len,
+		     const struct aes_key *key);
+
+#endif /* _CRYPTO_AES_ECB_H */