selftests/bpf: Reject graph kptr use after RCU unlockgrafted

Add a sleepable verifier test that loads a graph-node local kptr in an
explicit RCU read-side critical section, then passes its node to
bpf_rbtree_remove() after the section ends.

Before the verifier fix, the stale NON_OWN_REF flag makes the node look like
a live borrowed reference and the program is accepted. After the fix, the
pointer is demoted without NON_OWN_REF and the graph kfunc argument is
rejected.

Also exercise a graph kptr loaded while a spin lock provides implicit RCU
protection. The pointer must be invalidated when the lock is released, which
guards the required ordering between non-owning-reference invalidation and
RCU demotion.

Update the existing fault-protected load test state description. The
post-unlock pointer no longer carries NON_OWN_REF, but remains readable
because the load is rewritten to use BPF_PROBE_MEM.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 1023 insertions, 0 deletions

diff --git a/crypto/ahash.c b/crypto/ahash.c
new file mode 100644
index 000000000..d86c78f8d
--- /dev/null
+++ b/crypto/ahash.c
@@ -0,0 +1,1023 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Asynchronous Cryptographic Hash operations.
+ *
+ * This is the implementation of the ahash (asynchronous hash) API.  It differs
+ * from shash (synchronous hash) in that ahash supports asynchronous operations,
+ * and it hashes data from scatterlists instead of virtually addressed buffers.
+ *
+ * The ahash API provides access to both ahash and shash algorithms.  The shash
+ * API only provides access to shash algorithms.
+ *
+ * Copyright (c) 2008 Loc Ho <lho@amcc.com>
+ */
+
+#include <crypto/scatterwalk.h>
+#include <linux/cryptouser.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/seq_file.h>
+#include <linux/string.h>
+#include <linux/string_choices.h>
+#include <net/netlink.h>
+
+#include "hash.h"
+
+#define CRYPTO_ALG_TYPE_AHASH_MASK	0x0000000e
+
+static int ahash_def_finup(struct ahash_request *req);
+
+static inline bool crypto_ahash_block_only(struct crypto_ahash *tfm)
+{
+	return crypto_ahash_alg(tfm)->halg.base.cra_flags &
+	       CRYPTO_AHASH_ALG_BLOCK_ONLY;
+}
+
+static inline bool crypto_ahash_final_nonzero(struct crypto_ahash *tfm)
+{
+	return crypto_ahash_alg(tfm)->halg.base.cra_flags &
+	       CRYPTO_AHASH_ALG_FINAL_NONZERO;
+}
+
+static inline bool crypto_ahash_need_fallback(struct crypto_ahash *tfm)
+{
+	return crypto_ahash_alg(tfm)->halg.base.cra_flags &
+	       CRYPTO_ALG_NEED_FALLBACK;
+}
+
+static inline void ahash_op_done(void *data, int err,
+				 int (*finish)(struct ahash_request *, int))
+{
+	struct ahash_request *areq = data;
+	crypto_completion_t compl;
+
+	compl = areq->saved_complete;
+	data = areq->saved_data;
+	if (err == -EINPROGRESS)
+		goto out;
+
+	areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
+
+	err = finish(areq, err);
+	if (err == -EINPROGRESS || err == -EBUSY)
+		return;
+
+out:
+	compl(data, err);
+}
+
+static int hash_walk_next(struct crypto_hash_walk *walk)
+{
+	unsigned int offset = walk->offset;
+	unsigned int nbytes = min(walk->entrylen,
+				  ((unsigned int)(PAGE_SIZE)) - offset);
+
+	walk->data = kmap_local_page(walk->pg);
+	walk->data += offset;
+	walk->entrylen -= nbytes;
+	return nbytes;
+}
+
+static int hash_walk_new_entry(struct crypto_hash_walk *walk)
+{
+	struct scatterlist *sg;
+
+	sg = walk->sg;
+	walk->offset = sg->offset;
+	walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
+	walk->offset = offset_in_page(walk->offset);
+	walk->entrylen = sg->length;
+
+	if (walk->entrylen > walk->total)
+		walk->entrylen = walk->total;
+	walk->total -= walk->entrylen;
+
+	return hash_walk_next(walk);
+}
+
+int crypto_hash_walk_first(struct ahash_request *req,
+			   struct crypto_hash_walk *walk)
+{
+	walk->total = req->nbytes;
+	walk->entrylen = 0;
+
+	if (!walk->total)
+		return 0;
+
+	walk->flags = req->base.flags;
+
+	if (ahash_request_isvirt(req)) {
+		walk->data = req->svirt;
+		walk->total = 0;
+		return req->nbytes;
+	}
+
+	walk->sg = req->src;
+
+	return hash_walk_new_entry(walk);
+}
+EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
+
+int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
+{
+	if ((walk->flags & CRYPTO_AHASH_REQ_VIRT))
+		return err;
+
+	walk->data -= walk->offset;
+
+	kunmap_local(walk->data);
+	crypto_yield(walk->flags);
+
+	if (err)
+		return err;
+
+	if (walk->entrylen) {
+		walk->offset = 0;
+		walk->pg++;
+		return hash_walk_next(walk);
+	}
+
+	if (!walk->total)
+		return 0;
+
+	walk->sg = sg_next(walk->sg);
+
+	return hash_walk_new_entry(walk);
+}
+EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
+
+/*
+ * For an ahash tfm that is using an shash algorithm (instead of an ahash
+ * algorithm), this returns the underlying shash tfm.
+ */
+static inline struct crypto_shash *ahash_to_shash(struct crypto_ahash *tfm)
+{
+	return *(struct crypto_shash **)crypto_ahash_ctx(tfm);
+}
+
+static inline struct shash_desc *prepare_shash_desc(struct ahash_request *req,
+						    struct crypto_ahash *tfm)
+{
+	struct shash_desc *desc = ahash_request_ctx(req);
+
+	desc->tfm = ahash_to_shash(tfm);
+	return desc;
+}
+
+int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
+{
+	struct crypto_hash_walk walk;
+	int nbytes;
+
+	for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
+	     nbytes = crypto_hash_walk_done(&walk, nbytes))
+		nbytes = crypto_shash_update(desc, walk.data, nbytes);
+
+	return nbytes;
+}
+EXPORT_SYMBOL_GPL(shash_ahash_update);
+
+int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
+{
+	struct crypto_hash_walk walk;
+	int nbytes;
+
+	nbytes = crypto_hash_walk_first(req, &walk);
+	if (!nbytes)
+		return crypto_shash_final(desc, req->result);
+
+	do {
+		nbytes = crypto_hash_walk_last(&walk) ?
+			 crypto_shash_finup(desc, walk.data, nbytes,
+					    req->result) :
+			 crypto_shash_update(desc, walk.data, nbytes);
+		nbytes = crypto_hash_walk_done(&walk, nbytes);
+	} while (nbytes > 0);
+
+	return nbytes;
+}
+EXPORT_SYMBOL_GPL(shash_ahash_finup);
+
+int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
+{
+	unsigned int nbytes = req->nbytes;
+	struct scatterlist *sg;
+	unsigned int offset;
+	struct page *page;
+	const u8 *data;
+	int err;
+
+	data = req->svirt;
+	if (!nbytes || ahash_request_isvirt(req))
+		return crypto_shash_digest(desc, data, nbytes, req->result);
+
+	sg = req->src;
+	if (nbytes > sg->length)
+		return crypto_shash_init(desc) ?:
+		       shash_ahash_finup(req, desc);
+
+	page = sg_page(sg);
+	offset = sg->offset;
+	data = lowmem_page_address(page) + offset;
+	if (!IS_ENABLED(CONFIG_HIGHMEM))
+		return crypto_shash_digest(desc, data, nbytes, req->result);
+
+	page += offset >> PAGE_SHIFT;
+	offset = offset_in_page(offset);
+
+	if (nbytes > (unsigned int)PAGE_SIZE - offset)
+		return crypto_shash_init(desc) ?:
+		       shash_ahash_finup(req, desc);
+
+	data = kmap_local_page(page);
+	err = crypto_shash_digest(desc, data + offset, nbytes,
+				  req->result);
+	kunmap_local(data);
+	return err;
+}
+EXPORT_SYMBOL_GPL(shash_ahash_digest);
+
+static void crypto_exit_ahash_using_shash(struct crypto_tfm *tfm)
+{
+	struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
+
+	crypto_free_shash(*ctx);
+}
+
+static int crypto_init_ahash_using_shash(struct crypto_tfm *tfm)
+{
+	struct crypto_alg *calg = tfm->__crt_alg;
+	struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
+	struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
+	struct crypto_shash *shash;
+
+	if (!crypto_mod_get(calg))
+		return -EAGAIN;
+
+	shash = crypto_create_tfm(calg, &crypto_shash_type);
+	if (IS_ERR(shash)) {
+		crypto_mod_put(calg);
+		return PTR_ERR(shash);
+	}
+
+	crt->using_shash = true;
+	*ctx = shash;
+	tfm->exit = crypto_exit_ahash_using_shash;
+
+	crypto_ahash_set_flags(crt, crypto_shash_get_flags(shash) &
+				    CRYPTO_TFM_NEED_KEY);
+
+	return 0;
+}
+
+static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
+			  unsigned int keylen)
+{
+	return -ENOSYS;
+}
+
+static void ahash_set_needkey(struct crypto_ahash *tfm, struct ahash_alg *alg)
+{
+	if (alg->setkey != ahash_nosetkey &&
+	    !(alg->halg.base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
+		crypto_ahash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
+}
+
+int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
+			unsigned int keylen)
+{
+	if (likely(tfm->using_shash)) {
+		struct crypto_shash *shash = ahash_to_shash(tfm);
+		int err;
+
+		err = crypto_shash_setkey(shash, key, keylen);
+		if (unlikely(err)) {
+			crypto_ahash_set_flags(tfm,
+					       crypto_shash_get_flags(shash) &
+					       CRYPTO_TFM_NEED_KEY);
+			return err;
+		}
+	} else {
+		struct ahash_alg *alg = crypto_ahash_alg(tfm);
+		int err;
+
+		err = alg->setkey(tfm, key, keylen);
+		if (!err && crypto_ahash_need_fallback(tfm))
+			err = crypto_ahash_setkey(crypto_ahash_fb(tfm),
+						  key, keylen);
+		if (unlikely(err)) {
+			ahash_set_needkey(tfm, alg);
+			return err;
+		}
+	}
+	crypto_ahash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
+
+static int ahash_do_req_chain(struct ahash_request *req,
+			      int (*const *op)(struct ahash_request *req))
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	int err;
+
+	if (crypto_ahash_req_virt(tfm) || !ahash_request_isvirt(req))
+		return (*op)(req);
+
+	if (crypto_ahash_statesize(tfm) > HASH_MAX_STATESIZE)
+		return -ENOSYS;
+
+	if (!crypto_ahash_need_fallback(tfm))
+		return -ENOSYS;
+
+	if (crypto_hash_no_export_core(tfm))
+		return -ENOSYS;
+
+	{
+		u8 state[HASH_MAX_STATESIZE];
+
+		if (op == &crypto_ahash_alg(tfm)->digest) {
+			ahash_request_set_tfm(req, crypto_ahash_fb(tfm));
+			err = crypto_ahash_digest(req);
+			goto out_no_state;
+		}
+
+		err = crypto_ahash_export(req, state);
+		ahash_request_set_tfm(req, crypto_ahash_fb(tfm));
+		err = err ?: crypto_ahash_import(req, state);
+
+		if (op == &crypto_ahash_alg(tfm)->finup) {
+			err = err ?: crypto_ahash_finup(req);
+			goto out_no_state;
+		}
+
+		err = err ?:
+		      crypto_ahash_update(req) ?:
+		      crypto_ahash_export(req, state);
+
+		ahash_request_set_tfm(req, tfm);
+		return err ?: crypto_ahash_import(req, state);
+
+out_no_state:
+		ahash_request_set_tfm(req, tfm);
+		return err;
+	}
+}
+
+int crypto_ahash_init(struct ahash_request *req)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+
+	if (likely(tfm->using_shash))
+		return crypto_shash_init(prepare_shash_desc(req, tfm));
+	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
+		return -ENOKEY;
+	if (ahash_req_on_stack(req) && ahash_is_async(tfm))
+		return -EAGAIN;
+	if (crypto_ahash_block_only(tfm)) {
+		u8 *buf = ahash_request_ctx(req);
+
+		buf += crypto_ahash_reqsize(tfm) - 1;
+		*buf = 0;
+	}
+	return crypto_ahash_alg(tfm)->init(req);
+}
+EXPORT_SYMBOL_GPL(crypto_ahash_init);
+
+static void ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
+{
+	req->saved_complete = req->base.complete;
+	req->saved_data = req->base.data;
+	req->base.complete = cplt;
+	req->base.data = req;
+}
+
+static void ahash_restore_req(struct ahash_request *req)
+{
+	req->base.complete = req->saved_complete;
+	req->base.data = req->saved_data;
+}
+
+static int ahash_update_finish(struct ahash_request *req, int err)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	bool nonzero = crypto_ahash_final_nonzero(tfm);
+	int bs = crypto_ahash_blocksize(tfm);
+	u8 *blenp = ahash_request_ctx(req);
+	int blen;
+	u8 *buf;
+
+	blenp += crypto_ahash_reqsize(tfm) - 1;
+	blen = *blenp;
+	buf = blenp - bs;
+
+	if (blen) {
+		req->src = req->sg_head + 1;
+		if (sg_is_chain(req->src))
+			req->src = sg_chain_ptr(req->src);
+	}
+
+	req->nbytes += nonzero - blen;
+
+	blen = 0;
+	if (err >= 0) {
+		blen = err + nonzero;
+		err = 0;
+	}
+	if (ahash_request_isvirt(req))
+		memcpy(buf, req->svirt + req->nbytes - blen, blen);
+	else
+		memcpy_from_sglist(buf, req->src, req->nbytes - blen, blen);
+	*blenp = blen;
+
+	ahash_restore_req(req);
+
+	return err;
+}
+
+static void ahash_update_done(void *data, int err)
+{
+	ahash_op_done(data, err, ahash_update_finish);
+}
+
+int crypto_ahash_update(struct ahash_request *req)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	bool nonzero = crypto_ahash_final_nonzero(tfm);
+	int bs = crypto_ahash_blocksize(tfm);
+	u8 *blenp = ahash_request_ctx(req);
+	int blen, err;
+	u8 *buf;
+
+	if (likely(tfm->using_shash))
+		return shash_ahash_update(req, ahash_request_ctx(req));
+	if (ahash_req_on_stack(req) && ahash_is_async(tfm))
+		return -EAGAIN;
+	if (!crypto_ahash_block_only(tfm))
+		return ahash_do_req_chain(req, &crypto_ahash_alg(tfm)->update);
+
+	blenp += crypto_ahash_reqsize(tfm) - 1;
+	blen = *blenp;
+	buf = blenp - bs;
+
+	if (blen + req->nbytes < bs + nonzero) {
+		if (ahash_request_isvirt(req))
+			memcpy(buf + blen, req->svirt, req->nbytes);
+		else
+			memcpy_from_sglist(buf + blen, req->src, 0,
+					   req->nbytes);
+
+		*blenp += req->nbytes;
+		return 0;
+	}
+
+	if (blen) {
+		memset(req->sg_head, 0, sizeof(req->sg_head[0]));
+		sg_set_buf(req->sg_head, buf, blen);
+		if (req->src != req->sg_head + 1)
+			sg_chain(req->sg_head, 2, req->src);
+		req->src = req->sg_head;
+		req->nbytes += blen;
+	}
+	req->nbytes -= nonzero;
+
+	ahash_save_req(req, ahash_update_done);
+
+	err = ahash_do_req_chain(req, &crypto_ahash_alg(tfm)->update);
+	if (err == -EINPROGRESS || err == -EBUSY)
+		return err;
+
+	return ahash_update_finish(req, err);
+}
+EXPORT_SYMBOL_GPL(crypto_ahash_update);
+
+static int ahash_finup_finish(struct ahash_request *req, int err)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	u8 *blenp = ahash_request_ctx(req);
+	int blen;
+
+	blenp += crypto_ahash_reqsize(tfm) - 1;
+	blen = *blenp;
+
+	if (blen) {
+		if (sg_is_last(req->src))
+			req->src = NULL;
+		else {
+			req->src = req->sg_head + 1;
+			if (sg_is_chain(req->src))
+				req->src = sg_chain_ptr(req->src);
+		}
+		req->nbytes -= blen;
+	}
+
+	ahash_restore_req(req);
+
+	return err;
+}
+
+static void ahash_finup_done(void *data, int err)
+{
+	ahash_op_done(data, err, ahash_finup_finish);
+}
+
+int crypto_ahash_finup(struct ahash_request *req)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	int bs = crypto_ahash_blocksize(tfm);
+	u8 *blenp = ahash_request_ctx(req);
+	int blen, err;
+	u8 *buf;
+
+	if (likely(tfm->using_shash))
+		return shash_ahash_finup(req, ahash_request_ctx(req));
+	if (ahash_req_on_stack(req) && ahash_is_async(tfm))
+		return -EAGAIN;
+	if (!crypto_ahash_alg(tfm)->finup)
+		return ahash_def_finup(req);
+	if (!crypto_ahash_block_only(tfm))
+		return ahash_do_req_chain(req, &crypto_ahash_alg(tfm)->finup);
+
+	blenp += crypto_ahash_reqsize(tfm) - 1;
+	blen = *blenp;
+	buf = blenp - bs;
+
+	if (blen) {
+		memset(req->sg_head, 0, sizeof(req->sg_head[0]));
+		sg_set_buf(req->sg_head, buf, blen);
+		if (!req->src)
+			sg_mark_end(req->sg_head);
+		else if (req->src != req->sg_head + 1)
+			sg_chain(req->sg_head, 2, req->src);
+		req->src = req->sg_head;
+		req->nbytes += blen;
+	}
+
+	ahash_save_req(req, ahash_finup_done);
+
+	err = ahash_do_req_chain(req, &crypto_ahash_alg(tfm)->finup);
+	if (err == -EINPROGRESS || err == -EBUSY)
+		return err;
+
+	return ahash_finup_finish(req, err);
+}
+EXPORT_SYMBOL_GPL(crypto_ahash_finup);
+
+int crypto_ahash_digest(struct ahash_request *req)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+
+	if (likely(tfm->using_shash))
+		return shash_ahash_digest(req, prepare_shash_desc(req, tfm));
+	if (ahash_req_on_stack(req) && ahash_is_async(tfm))
+		return -EAGAIN;
+	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
+		return -ENOKEY;
+	return ahash_do_req_chain(req, &crypto_ahash_alg(tfm)->digest);
+}
+EXPORT_SYMBOL_GPL(crypto_ahash_digest);
+
+static void ahash_def_finup_done2(void *data, int err)
+{
+	struct ahash_request *areq = data;
+
+	if (err == -EINPROGRESS)
+		return;
+
+	ahash_restore_req(areq);
+	ahash_request_complete(areq, err);
+}
+
+static int ahash_def_finup_finish1(struct ahash_request *req, int err)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+
+	if (err)
+		goto out;
+
+	req->base.complete = ahash_def_finup_done2;
+
+	err = crypto_ahash_alg(tfm)->final(req);
+	if (err == -EINPROGRESS || err == -EBUSY)
+		return err;
+
+out:
+	ahash_restore_req(req);
+	return err;
+}
+
+static void ahash_def_finup_done1(void *data, int err)
+{
+	ahash_op_done(data, err, ahash_def_finup_finish1);
+}
+
+static int ahash_def_finup(struct ahash_request *req)
+{
+	int err;
+
+	ahash_save_req(req, ahash_def_finup_done1);
+
+	err = crypto_ahash_update(req);
+	if (err == -EINPROGRESS || err == -EBUSY)
+		return err;
+
+	return ahash_def_finup_finish1(req, err);
+}
+
+int crypto_ahash_export_core(struct ahash_request *req, void *out)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+
+	if (likely(tfm->using_shash))
+		return crypto_shash_export_core(ahash_request_ctx(req), out);
+	return crypto_ahash_alg(tfm)->export_core(req, out);
+}
+EXPORT_SYMBOL_GPL(crypto_ahash_export_core);
+
+int crypto_ahash_export(struct ahash_request *req, void *out)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+
+	if (likely(tfm->using_shash))
+		return crypto_shash_export(ahash_request_ctx(req), out);
+	if (crypto_ahash_block_only(tfm)) {
+		unsigned int plen = crypto_ahash_blocksize(tfm) + 1;
+		unsigned int reqsize = crypto_ahash_reqsize(tfm);
+		unsigned int ss = crypto_ahash_statesize(tfm);
+		u8 *buf = ahash_request_ctx(req);
+
+		memcpy(out + ss - plen, buf + reqsize - plen, plen);
+	}
+	return crypto_ahash_alg(tfm)->export(req, out);
+}
+EXPORT_SYMBOL_GPL(crypto_ahash_export);
+
+int crypto_ahash_import_core(struct ahash_request *req, const void *in)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+
+	if (likely(tfm->using_shash))
+		return crypto_shash_import_core(prepare_shash_desc(req, tfm),
+						in);
+	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
+		return -ENOKEY;
+	if (crypto_ahash_block_only(tfm)) {
+		unsigned int reqsize = crypto_ahash_reqsize(tfm);
+		u8 *buf = ahash_request_ctx(req);
+
+		buf[reqsize - 1] = 0;
+	}
+	return crypto_ahash_alg(tfm)->import_core(req, in);
+}
+EXPORT_SYMBOL_GPL(crypto_ahash_import_core);
+
+int crypto_ahash_import(struct ahash_request *req, const void *in)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+
+	if (likely(tfm->using_shash))
+		return crypto_shash_import(prepare_shash_desc(req, tfm), in);
+	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
+		return -ENOKEY;
+	if (crypto_ahash_block_only(tfm)) {
+		unsigned int plen = crypto_ahash_blocksize(tfm) + 1;
+		unsigned int reqsize = crypto_ahash_reqsize(tfm);
+		unsigned int ss = crypto_ahash_statesize(tfm);
+		u8 *buf = ahash_request_ctx(req);
+
+		memcpy(buf + reqsize - plen, in + ss - plen, plen);
+		if (buf[reqsize - 1] >= plen)
+			return -EOVERFLOW;
+	}
+	return crypto_ahash_alg(tfm)->import(req, in);
+}
+EXPORT_SYMBOL_GPL(crypto_ahash_import);
+
+static void crypto_ahash_exit_tfm(struct crypto_tfm *tfm)
+{
+	struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
+	struct ahash_alg *alg = crypto_ahash_alg(hash);
+
+	if (alg->exit_tfm)
+		alg->exit_tfm(hash);
+	else if (tfm->__crt_alg->cra_exit)
+		tfm->__crt_alg->cra_exit(tfm);
+
+	if (crypto_ahash_need_fallback(hash))
+		crypto_free_ahash(crypto_ahash_fb(hash));
+}
+
+static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
+{
+	struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
+	struct ahash_alg *alg = crypto_ahash_alg(hash);
+	struct crypto_ahash *fb = NULL;
+	int err;
+
+	crypto_ahash_set_statesize(hash, alg->halg.statesize);
+	crypto_ahash_set_reqsize(hash, crypto_tfm_alg_reqsize(tfm));
+
+	if (tfm->__crt_alg->cra_type == &crypto_shash_type)
+		return crypto_init_ahash_using_shash(tfm);
+
+	if (crypto_ahash_need_fallback(hash)) {
+		fb = crypto_alloc_ahash(crypto_ahash_alg_name(hash),
+					CRYPTO_ALG_REQ_VIRT,
+					CRYPTO_ALG_ASYNC |
+					CRYPTO_ALG_REQ_VIRT |
+					CRYPTO_AHASH_ALG_NO_EXPORT_CORE);
+		if (IS_ERR(fb))
+			return PTR_ERR(fb);
+
+		tfm->fb = crypto_ahash_tfm(fb);
+	}
+
+	ahash_set_needkey(hash, alg);
+
+	tfm->exit = crypto_ahash_exit_tfm;
+
+	if (alg->init_tfm)
+		err = alg->init_tfm(hash);
+	else if (tfm->__crt_alg->cra_init)
+		err = tfm->__crt_alg->cra_init(tfm);
+	else
+		return 0;
+
+	if (err)
+		goto out_free_sync_hash;
+
+	if (!ahash_is_async(hash) && crypto_ahash_reqsize(hash) >
+				     MAX_SYNC_HASH_REQSIZE)
+		goto out_exit_tfm;
+
+	BUILD_BUG_ON(HASH_MAX_DESCSIZE > MAX_SYNC_HASH_REQSIZE);
+	if (crypto_ahash_reqsize(hash) < HASH_MAX_DESCSIZE)
+		crypto_ahash_set_reqsize(hash, HASH_MAX_DESCSIZE);
+
+	return 0;
+
+out_exit_tfm:
+	if (alg->exit_tfm)
+		alg->exit_tfm(hash);
+	else if (tfm->__crt_alg->cra_exit)
+		tfm->__crt_alg->cra_exit(tfm);
+	err = -EINVAL;
+out_free_sync_hash:
+	crypto_free_ahash(fb);
+	return err;
+}
+
+static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
+{
+	if (alg->cra_type == &crypto_shash_type)
+		return sizeof(struct crypto_shash *);
+
+	return crypto_alg_extsize(alg);
+}
+
+static void crypto_ahash_free_instance(struct crypto_instance *inst)
+{
+	struct ahash_instance *ahash = ahash_instance(inst);
+
+	ahash->free(ahash);
+}
+
+static int __maybe_unused crypto_ahash_report(
+	struct sk_buff *skb, struct crypto_alg *alg)
+{
+	struct crypto_report_hash rhash = {
+		.type = "ahash",
+	};
+
+	rhash.blocksize = alg->cra_blocksize;
+	rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
+
+	return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
+}
+
+static void __maybe_unused crypto_ahash_show(struct seq_file *m,
+					     struct crypto_alg *alg)
+{
+	seq_printf(m, "type         : ahash\n");
+	seq_printf(m, "async        : %s\n",
+		   str_yes_no(alg->cra_flags & CRYPTO_ALG_ASYNC));
+	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
+	seq_printf(m, "digestsize   : %u\n",
+		   __crypto_hash_alg_common(alg)->digestsize);
+}
+
+static const struct crypto_type crypto_ahash_type = {
+	.extsize = crypto_ahash_extsize,
+	.init_tfm = crypto_ahash_init_tfm,
+	.free = crypto_ahash_free_instance,
+#ifdef CONFIG_PROC_FS
+	.show = crypto_ahash_show,
+#endif
+#if IS_ENABLED(CONFIG_CRYPTO_USER)
+	.report = crypto_ahash_report,
+#endif
+	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
+	.maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
+	.type = CRYPTO_ALG_TYPE_AHASH,
+	.tfmsize = offsetof(struct crypto_ahash, base),
+	.algsize = offsetof(struct ahash_alg, halg.base),
+};
+
+int crypto_grab_ahash(struct crypto_ahash_spawn *spawn,
+		      struct crypto_instance *inst,
+		      const char *name, u32 type, u32 mask)
+{
+	spawn->base.frontend = &crypto_ahash_type;
+	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
+}
+EXPORT_SYMBOL_GPL(crypto_grab_ahash);
+
+struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
+					u32 mask)
+{
+	return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
+}
+EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
+
+int crypto_has_ahash(const char *alg_name, u32 type, u32 mask)
+{
+	return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask);
+}
+EXPORT_SYMBOL_GPL(crypto_has_ahash);
+
+bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg)
+{
+	struct crypto_alg *alg = &halg->base;
+
+	if (alg->cra_type == &crypto_shash_type)
+		return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg));
+
+	return __crypto_ahash_alg(alg)->setkey != ahash_nosetkey;
+}
+EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey);
+
+static int ahash_default_export_core(struct ahash_request *req, void *out)
+{
+	return -ENOSYS;
+}
+
+static int ahash_default_import_core(struct ahash_request *req, const void *in)
+{
+	return -ENOSYS;
+}
+
+static int ahash_prepare_alg(struct ahash_alg *alg)
+{
+	struct crypto_alg *base = &alg->halg.base;
+	int err;
+
+	if (alg->halg.statesize == 0)
+		return -EINVAL;
+
+	if (base->cra_reqsize && base->cra_reqsize < alg->halg.statesize)
+		return -EINVAL;
+
+	if (!(base->cra_flags & CRYPTO_ALG_ASYNC) &&
+	    base->cra_reqsize > MAX_SYNC_HASH_REQSIZE)
+		return -EINVAL;
+
+	if (base->cra_flags & CRYPTO_ALG_NEED_FALLBACK &&
+	    base->cra_flags & CRYPTO_ALG_NO_FALLBACK)
+		return -EINVAL;
+
+	err = hash_prepare_alg(&alg->halg);
+	if (err)
+		return err;
+
+	base->cra_type = &crypto_ahash_type;
+	base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
+
+	if ((base->cra_flags ^ CRYPTO_ALG_REQ_VIRT) &
+	    (CRYPTO_ALG_ASYNC | CRYPTO_ALG_REQ_VIRT) &&
+	    !(base->cra_flags & CRYPTO_ALG_NO_FALLBACK))
+		base->cra_flags |= CRYPTO_ALG_NEED_FALLBACK;
+
+	if (!alg->setkey)
+		alg->setkey = ahash_nosetkey;
+
+	if (base->cra_flags & CRYPTO_AHASH_ALG_BLOCK_ONLY) {
+		BUILD_BUG_ON(MAX_ALGAPI_BLOCKSIZE >= 256);
+		if (!alg->finup)
+			return -EINVAL;
+
+		base->cra_reqsize += base->cra_blocksize + 1;
+		alg->halg.statesize += base->cra_blocksize + 1;
+		alg->export_core = alg->export;
+		alg->import_core = alg->import;
+	} else if (!alg->export_core || !alg->import_core) {
+		alg->export_core = ahash_default_export_core;
+		alg->import_core = ahash_default_import_core;
+		base->cra_flags |= CRYPTO_AHASH_ALG_NO_EXPORT_CORE;
+	}
+
+	return 0;
+}
+
+int crypto_register_ahash(struct ahash_alg *alg)
+{
+	struct crypto_alg *base = &alg->halg.base;
+	int err;
+
+	err = ahash_prepare_alg(alg);
+	if (err)
+		return err;
+
+	return crypto_register_alg(base);
+}
+EXPORT_SYMBOL_GPL(crypto_register_ahash);
+
+void crypto_unregister_ahash(struct ahash_alg *alg)
+{
+	crypto_unregister_alg(&alg->halg.base);
+}
+EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
+
+int crypto_register_ahashes(struct ahash_alg *algs, int count)
+{
+	int i, ret;
+
+	for (i = 0; i < count; i++) {
+		ret = crypto_register_ahash(&algs[i]);
+		if (ret) {
+			crypto_unregister_ahashes(algs, i);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(crypto_register_ahashes);
+
+void crypto_unregister_ahashes(struct ahash_alg *algs, int count)
+{
+	int i;
+
+	for (i = count - 1; i >= 0; --i)
+		crypto_unregister_ahash(&algs[i]);
+}
+EXPORT_SYMBOL_GPL(crypto_unregister_ahashes);
+
+int ahash_register_instance(struct crypto_template *tmpl,
+			    struct ahash_instance *inst)
+{
+	int err;
+
+	if (WARN_ON(!inst->free))
+		return -EINVAL;
+
+	err = ahash_prepare_alg(&inst->alg);
+	if (err)
+		return err;
+
+	return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
+}
+EXPORT_SYMBOL_GPL(ahash_register_instance);
+
+void ahash_request_free(struct ahash_request *req)
+{
+	if (unlikely(!req))
+		return;
+
+	if (!ahash_req_on_stack(req)) {
+		kfree(req);
+		return;
+	}
+
+	ahash_request_zero(req);
+}
+EXPORT_SYMBOL_GPL(ahash_request_free);
+
+int crypto_hash_digest(struct crypto_ahash *tfm, const u8 *data,
+		       unsigned int len, u8 *out)
+{
+	HASH_REQUEST_ON_STACK(req, crypto_ahash_fb(tfm));
+	int err;
+
+	ahash_request_set_callback(req, 0, NULL, NULL);
+	ahash_request_set_virt(req, data, out, len);
+	err = crypto_ahash_digest(req);
+
+	ahash_request_zero(req);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(crypto_hash_digest);
+
+void ahash_free_singlespawn_instance(struct ahash_instance *inst)
+{
+	crypto_drop_spawn(ahash_instance_ctx(inst));
+	kfree(inst);
+}
+EXPORT_SYMBOL_GPL(ahash_free_singlespawn_instance);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Asynchronous cryptographic hash type");