6.17-stable review patch. If anyone has any objections, please let me know.
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From: Harald Freudenberger freude@linux.ibm.com
[ Upstream commit 3ac2939bc4341ac28700a2ed0c345ba7e7bdb6fd ]
The phmac implementation used the req->nbytes field on combined operations (finup, digest) to track the state: with req->nbytes > 0 the update needs to be processed, while req->nbytes == 0 means to do the final operation. For this purpose the req->nbytes field was set to 0 after successful update operation. However, aead uses the req->nbytes field after a successful hash operation to determine the amount of data to en/decrypt. So an implementation must not modify the nbytes field.
Fixed by a slight rework on the phmac implementation. There is now a new field async_op in the request context which tracks the (asynch) operation to process. So the 'state' via req->nbytes is not needed any more and now this field is untouched and may be evaluated even after a request is processed by the phmac implementation.
Fixes: cbbc675506cc ("crypto: s390 - New s390 specific protected key hash phmac") Reported-by: Ingo Franzki ifranzki@linux.ibm.com Signed-off-by: Harald Freudenberger freude@linux.ibm.com Tested-by: Ingo Franzki ifranzki@linux.ibm.com Reviewed-by: Ingo Franzki ifranzki@linux.ibm.com Reviewed-by: Holger Dengler dengler@linux.ibm.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Sasha Levin sashal@kernel.org --- arch/s390/crypto/phmac_s390.c | 52 +++++++++++++++++++++++------------ 1 file changed, 34 insertions(+), 18 deletions(-)
diff --git a/arch/s390/crypto/phmac_s390.c b/arch/s390/crypto/phmac_s390.c index 7ecfdc4fba2d0..89f3e6d8fd897 100644 --- a/arch/s390/crypto/phmac_s390.c +++ b/arch/s390/crypto/phmac_s390.c @@ -169,11 +169,18 @@ struct kmac_sha2_ctx { u64 buflen[2]; };
+enum async_op { + OP_NOP = 0, + OP_UPDATE, + OP_FINAL, + OP_FINUP, +}; + /* phmac request context */ struct phmac_req_ctx { struct hash_walk_helper hwh; struct kmac_sha2_ctx kmac_ctx; - bool final; + enum async_op async_op; };
/* @@ -610,6 +617,7 @@ static int phmac_update(struct ahash_request *req) * using engine to serialize requests. */ if (rc == 0 || rc == -EKEYEXPIRED) { + req_ctx->async_op = OP_UPDATE; atomic_inc(&tfm_ctx->via_engine_ctr); rc = crypto_transfer_hash_request_to_engine(phmac_crypto_engine, req); if (rc != -EINPROGRESS) @@ -647,8 +655,7 @@ static int phmac_final(struct ahash_request *req) * using engine to serialize requests. */ if (rc == 0 || rc == -EKEYEXPIRED) { - req->nbytes = 0; - req_ctx->final = true; + req_ctx->async_op = OP_FINAL; atomic_inc(&tfm_ctx->via_engine_ctr); rc = crypto_transfer_hash_request_to_engine(phmac_crypto_engine, req); if (rc != -EINPROGRESS) @@ -676,13 +683,16 @@ static int phmac_finup(struct ahash_request *req) if (rc) goto out;
+ req_ctx->async_op = OP_FINUP; + /* Try synchronous operations if no active engine usage */ if (!atomic_read(&tfm_ctx->via_engine_ctr)) { rc = phmac_kmac_update(req, false); if (rc == 0) - req->nbytes = 0; + req_ctx->async_op = OP_FINAL; } - if (!rc && !req->nbytes && !atomic_read(&tfm_ctx->via_engine_ctr)) { + if (!rc && req_ctx->async_op == OP_FINAL && + !atomic_read(&tfm_ctx->via_engine_ctr)) { rc = phmac_kmac_final(req, false); if (rc == 0) goto out; @@ -694,7 +704,7 @@ static int phmac_finup(struct ahash_request *req) * using engine to serialize requests. */ if (rc == 0 || rc == -EKEYEXPIRED) { - req_ctx->final = true; + /* req->async_op has been set to either OP_FINUP or OP_FINAL */ atomic_inc(&tfm_ctx->via_engine_ctr); rc = crypto_transfer_hash_request_to_engine(phmac_crypto_engine, req); if (rc != -EINPROGRESS) @@ -855,15 +865,16 @@ static int phmac_do_one_request(struct crypto_engine *engine, void *areq)
/* * Three kinds of requests come in here: - * update when req->nbytes > 0 and req_ctx->final is false - * final when req->nbytes = 0 and req_ctx->final is true - * finup when req->nbytes > 0 and req_ctx->final is true - * For update and finup the hwh walk needs to be prepared and - * up to date but the actual nr of bytes in req->nbytes may be - * any non zero number. For final there is no hwh walk needed. + * 1. req->async_op == OP_UPDATE with req->nbytes > 0 + * 2. req->async_op == OP_FINUP with req->nbytes > 0 + * 3. req->async_op == OP_FINAL + * For update and finup the hwh walk has already been prepared + * by the caller. For final there is no hwh walk needed. */
- if (req->nbytes) { + switch (req_ctx->async_op) { + case OP_UPDATE: + case OP_FINUP: rc = phmac_kmac_update(req, true); if (rc == -EKEYEXPIRED) { /* @@ -880,10 +891,11 @@ static int phmac_do_one_request(struct crypto_engine *engine, void *areq) hwh_advance(hwh, rc); goto out; } - req->nbytes = 0; - } - - if (req_ctx->final) { + if (req_ctx->async_op == OP_UPDATE) + break; + req_ctx->async_op = OP_FINAL; + fallthrough; + case OP_FINAL: rc = phmac_kmac_final(req, true); if (rc == -EKEYEXPIRED) { /* @@ -897,10 +909,14 @@ static int phmac_do_one_request(struct crypto_engine *engine, void *areq) cond_resched(); return -ENOSPC; } + break; + default: + /* unknown/unsupported/unimplemented asynch op */ + return -EOPNOTSUPP; }
out: - if (rc || req_ctx->final) + if (rc || req_ctx->async_op == OP_FINAL) memzero_explicit(kmac_ctx, sizeof(*kmac_ctx)); pr_debug("request complete with rc=%d\n", rc); local_bh_disable();