1 files changed, 21 insertions, 7 deletions

diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index 9de6dc614d..ed48dcddd5 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -80,24 +80,23 @@ static void notrace persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
 	uint8_t *data, size_t len, uint8_t *ecc)
 {
 	int i;
-	uint16_t par[prz->ecc_info.ecc_size];
 
 	/* Initialize the parity buffer */
-	memset(par, 0, sizeof(par));
-	encode_rs8(prz->rs_decoder, data, len, par, 0);
+	memset(prz->ecc_info.par, 0,
+	       prz->ecc_info.ecc_size * sizeof(prz->ecc_info.par[0]));
+	encode_rs8(prz->rs_decoder, data, len, prz->ecc_info.par, 0);
 	for (i = 0; i < prz->ecc_info.ecc_size; i++)
-		ecc[i] = par[i];
+		ecc[i] = prz->ecc_info.par[i];
 }
 
 static int persistent_ram_decode_rs8(struct persistent_ram_zone *prz,
 	void *data, size_t len, uint8_t *ecc)
 {
 	int i;
-	uint16_t par[prz->ecc_info.ecc_size];
 
 	for (i = 0; i < prz->ecc_info.ecc_size; i++)
-		par[i] = ecc[i];
-	return decode_rs8(prz->rs_decoder, data, par, len,
+		prz->ecc_info.par[i] = ecc[i];
+	return decode_rs8(prz->rs_decoder, data, prz->ecc_info.par, len,
 				NULL, 0, NULL, 0, NULL);
 }
 
@@ -210,6 +209,15 @@ static int persistent_ram_init_ecc(struct persistent_ram_zone *prz,
 		return -EINVAL;
 	}
 
+	/* allocate workspace instead of using stack VLA */
+	prz->ecc_info.par = kmalloc_array(prz->ecc_info.ecc_size,
+					  sizeof(*prz->ecc_info.par),
+					  GFP_KERNEL);
+	if (!prz->ecc_info.par) {
+		pr_err("cannot allocate ECC parity workspace\n");
+		return -ENOMEM;
+	}
+
 	prz->corrected_bytes = 0;
 	prz->bad_blocks = 0;
 
@@ -393,6 +401,12 @@ void persistent_ram_free(struct persistent_ram_zone *prz)
 		release_sdram_region(prz->res);
 		prz->res = NULL;
 	}
+	if (prz->rs_decoder) {
+		free_rs(prz->rs_decoder);
+		prz->rs_decoder = NULL;
+	}
+	kfree(prz->ecc_info.par);
+	prz->ecc_info.par = NULL;
 
 	persistent_ram_free_old(prz);
 	kfree(prz);