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, 155 insertions, 0 deletions

diff --git a/include/crypto/internal/akcipher.h b/include/crypto/internal/akcipher.h
new file mode 100644
index 000000000..14ee62bc5
--- /dev/null
+++ b/include/crypto/internal/akcipher.h
@@ -0,0 +1,155 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Public Key Encryption
+ *
+ * Copyright (c) 2015, Intel Corporation
+ * Authors: Tadeusz Struk <tadeusz.struk@intel.com>
+ */
+#ifndef _CRYPTO_AKCIPHER_INT_H
+#define _CRYPTO_AKCIPHER_INT_H
+#include <crypto/akcipher.h>
+#include <crypto/algapi.h>
+
+struct akcipher_instance {
+	void (*free)(struct akcipher_instance *inst);
+	union {
+		struct {
+			char head[offsetof(struct akcipher_alg, base)];
+			struct crypto_instance base;
+		} s;
+		struct akcipher_alg alg;
+	};
+};
+
+struct crypto_akcipher_spawn {
+	struct crypto_spawn base;
+};
+
+/*
+ * Transform internal helpers.
+ */
+static inline void *akcipher_request_ctx(struct akcipher_request *req)
+{
+	return req->__ctx;
+}
+
+static inline void *akcipher_request_ctx_dma(struct akcipher_request *req)
+{
+	unsigned int align = crypto_dma_align();
+
+	if (align <= crypto_tfm_ctx_alignment())
+		align = 1;
+
+	return PTR_ALIGN(akcipher_request_ctx(req), align);
+}
+
+static inline void akcipher_set_reqsize(struct crypto_akcipher *akcipher,
+					unsigned int reqsize)
+{
+	akcipher->reqsize = reqsize;
+}
+
+static inline void akcipher_set_reqsize_dma(struct crypto_akcipher *akcipher,
+					    unsigned int reqsize)
+{
+	reqsize += crypto_dma_align() & ~(crypto_tfm_ctx_alignment() - 1);
+	akcipher->reqsize = reqsize;
+}
+
+static inline void *akcipher_tfm_ctx(struct crypto_akcipher *tfm)
+{
+	return crypto_tfm_ctx(&tfm->base);
+}
+
+static inline void *akcipher_tfm_ctx_dma(struct crypto_akcipher *tfm)
+{
+	return crypto_tfm_ctx_dma(&tfm->base);
+}
+
+static inline void akcipher_request_complete(struct akcipher_request *req,
+					     int err)
+{
+	crypto_request_complete(&req->base, err);
+}
+
+static inline const char *akcipher_alg_name(struct crypto_akcipher *tfm)
+{
+	return crypto_akcipher_tfm(tfm)->__crt_alg->cra_name;
+}
+
+static inline struct crypto_instance *akcipher_crypto_instance(
+		struct akcipher_instance *inst)
+{
+	return container_of(&inst->alg.base, struct crypto_instance, alg);
+}
+
+static inline struct akcipher_instance *akcipher_instance(
+		struct crypto_instance *inst)
+{
+	return container_of(&inst->alg, struct akcipher_instance, alg.base);
+}
+
+static inline struct akcipher_instance *akcipher_alg_instance(
+		struct crypto_akcipher *akcipher)
+{
+	return akcipher_instance(crypto_tfm_alg_instance(&akcipher->base));
+}
+
+static inline void *akcipher_instance_ctx(struct akcipher_instance *inst)
+{
+	return crypto_instance_ctx(akcipher_crypto_instance(inst));
+}
+
+int crypto_grab_akcipher(struct crypto_akcipher_spawn *spawn,
+			 struct crypto_instance *inst,
+			 const char *name, u32 type, u32 mask);
+
+static inline struct crypto_akcipher *crypto_spawn_akcipher(
+		struct crypto_akcipher_spawn *spawn)
+{
+	return crypto_spawn_tfm2(&spawn->base);
+}
+
+static inline void crypto_drop_akcipher(struct crypto_akcipher_spawn *spawn)
+{
+	crypto_drop_spawn(&spawn->base);
+}
+
+static inline struct akcipher_alg *crypto_spawn_akcipher_alg(
+		struct crypto_akcipher_spawn *spawn)
+{
+	return container_of(spawn->base.alg, struct akcipher_alg, base);
+}
+
+/**
+ * crypto_register_akcipher() -- Register public key algorithm
+ *
+ * Function registers an implementation of a public key cipher algorithm
+ *
+ * @alg:	algorithm definition
+ *
+ * Return: zero on success; error code in case of error
+ */
+int crypto_register_akcipher(struct akcipher_alg *alg);
+
+/**
+ * crypto_unregister_akcipher() -- Unregister public key algorithm
+ *
+ * Function unregisters an implementation of a public key cipher algorithm
+ *
+ * @alg:	algorithm definition
+ */
+void crypto_unregister_akcipher(struct akcipher_alg *alg);
+
+/**
+ * akcipher_register_instance() -- Unregister public key template instance
+ *
+ * Function registers an implementation of an asymmetric key algorithm
+ * created from a template
+ *
+ * @tmpl:	the template from which the algorithm was created
+ * @inst:	the template instance
+ */
+int akcipher_register_instance(struct crypto_template *tmpl,
+		struct akcipher_instance *inst);
+#endif