nvmem: zynqmp_nvmem: Fix buffer size in DMA and memcpy

Buffer size used in dma allocation and memcpy is wrong.
It can lead to undersized DMA buffer access and possible
memory corruption. use correct buffer size in dma_alloc_coherent
and memcpy.

Fixes: 737c0c8 ("nvmem: zynqmp_nvmem: Add support to access efuse")
Cc: [email protected]
Signed-off-by: Ivan Vera <[email protected]>
Signed-off-by: Harish Ediga <[email protected]>
Signed-off-by: Harsh Jain <[email protected]>
Signed-off-by: Srinivas Kandagatla <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: JIvanVera

drivers/nvmem/zynqmp_nvmem.c

@@ -66,7 +66,7 @@ static int zynqmp_efuse_access(void *context, unsigned int offset,
 	dma_addr_t dma_buf;
 	size_t words = bytes / WORD_INBYTES;
 	int ret;
-	int value;
+	unsigned int value;
 	char *data;
 
 	if (bytes % WORD_INBYTES != 0) {
@@ -80,7 +80,7 @@ static int zynqmp_efuse_access(void *context, unsigned int offset,
 	}
 
 	if (pufflag == 1 && flag == EFUSE_WRITE) {
-		memcpy(&value, val, bytes);
+		memcpy(&value, val, sizeof(value));
 		if ((offset == EFUSE_PUF_START_OFFSET ||
 		     offset == EFUSE_PUF_MID_OFFSET) &&
 		    value & P_USER_0_64_UPPER_MASK) {
@@ -100,7 +100,7 @@ static int zynqmp_efuse_access(void *context, unsigned int offset,
 	if (!efuse)
 		return -ENOMEM;
 
-	data = dma_alloc_coherent(dev, sizeof(bytes),
+	data = dma_alloc_coherent(dev, bytes,
 				  &dma_buf, GFP_KERNEL);
 	if (!data) {
 		ret = -ENOMEM;
@@ -134,7 +134,7 @@ static int zynqmp_efuse_access(void *context, unsigned int offset,
 	if (flag == EFUSE_READ)
 		memcpy(val, data, bytes);
 efuse_access_err:
-	dma_free_coherent(dev, sizeof(bytes),
+	dma_free_coherent(dev, bytes,
 			  data, dma_buf);
 efuse_data_fail:
 	dma_free_coherent(dev, sizeof(struct xilinx_efuse),