crypto: nx - fix concurrency issue

The NX driver uses the transformation context to store several fields
containing data related to the state of the operations in progress.
Since a single tfm can be used by different kernel threads at the same
time, we need to protect the data stored into the context.

This patch makes use of spin locks to protect the data where a race
condition can happen.

Reviewed-by: Fionnuala Gunter <fin@linux.vnet.ibm.com>
Reviewed-by: Joy Latten <jmlatten@linux.vnet.ibm.com>
Signed-off-by: Marcelo Cerri <mhcerri@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 16 insertions, 0 deletions

diff --git a/drivers/crypto/nx/nx-sha256.c b/drivers/crypto/nx/nx-sha256.c
index 254b01abef64..6547a7104bf6 100644
--- a/drivers/crypto/nx/nx-sha256.c
+++ b/drivers/crypto/nx/nx-sha256.c
@@ -57,8 +57,11 @@ static int nx_sha256_update(struct shash_desc *desc, const u8 *data,
 	struct nx_sg *in_sg;
 	u64 to_process, leftover, total;
 	u32 max_sg_len;
+	unsigned long irq_flags;
 	int rc = 0;
 
+	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
+
 	/* 2 cases for total data len:
 	 *  1: < SHA256_BLOCK_SIZE: copy into state, return 0
 	 *  2: >= SHA256_BLOCK_SIZE: process X blocks, copy in leftover
@@ -136,6 +139,7 @@ static int nx_sha256_update(struct shash_desc *desc, const u8 *data,
 		memcpy(sctx->buf, data, leftover);
 	sctx->count = leftover;
 out:
+	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
 	return rc;
 }
 
@@ -146,8 +150,11 @@ static int nx_sha256_final(struct shash_desc *desc, u8 *out)
 	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
 	struct nx_sg *in_sg, *out_sg;
 	u32 max_sg_len;
+	unsigned long irq_flags;
 	int rc;
 
+	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
+
 	max_sg_len = min_t(u32, nx_driver.of.max_sg_len, nx_ctx->ap->sglen);
 
 	if (NX_CPB_FDM(csbcpb) & NX_FDM_CONTINUATION) {
@@ -186,6 +193,7 @@ static int nx_sha256_final(struct shash_desc *desc, u8 *out)
 		     &(nx_ctx->stats->sha256_bytes));
 	memcpy(out, csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
 out:
+	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
 	return rc;
 }
 
@@ -195,6 +203,9 @@ static int nx_sha256_export(struct shash_desc *desc, void *out)
 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
 	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
 	struct sha256_state *octx = out;
+	unsigned long irq_flags;
+
+	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
 
 	octx->count = sctx->count +
 		      (csbcpb->cpb.sha256.message_bit_length / 8);
@@ -217,6 +228,7 @@ static int nx_sha256_export(struct shash_desc *desc, void *out)
 		octx->state[7] = SHA256_H7;
 	}
 
+	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
 	return 0;
 }
 
@@ -226,6 +238,9 @@ static int nx_sha256_import(struct shash_desc *desc, const void *in)
 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
 	struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
 	const struct sha256_state *ictx = in;
+	unsigned long irq_flags;
+
+	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
 
 	memcpy(sctx->buf, ictx->buf, sizeof(ictx->buf));
 
@@ -240,6 +255,7 @@ static int nx_sha256_import(struct shash_desc *desc, const void *in)
 		NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
 	}
 
+	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
 	return 0;
 }