From: Len Baker <len.baker@gmx.com>
Date: Sat, 24 Jul 2021 14:21:52 +0200
Subject: Bluetooth: btmrvl_sdio: Remove all strcpy() uses
Patch-mainline: v5.15-rc1
Git-commit: 785077fa2d6791d036b4227924276534ae0f192f
References: jsc#PED-1407

strcpy() performs no bounds checking on the destination buffer. This
could result in linear overflows beyond the end of the buffer, leading
to all kinds of misbehaviors. The safe replacement is strscpy() but in
this case it is better to use the scnprintf to simplify the arithmetic.

This is a previous step in the path to remove the strcpy() function
entirely from the kernel.

Signed-off-by: Len Baker <len.baker@gmx.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Lee, Chun-Yi <jlee@suse.com>
---
 drivers/bluetooth/btmrvl_sdio.c |   29 ++++++++++++++---------------
 1 file changed, 14 insertions(+), 15 deletions(-)

--- a/drivers/bluetooth/btmrvl_sdio.c
+++ b/drivers/bluetooth/btmrvl_sdio.c
@@ -1350,6 +1350,7 @@ static void btmrvl_sdio_coredump(struct
 	u8 *dbg_ptr, *end_ptr, *fw_dump_data, *fw_dump_ptr;
 	u8 dump_num = 0, idx, i, read_reg, doneflag = 0;
 	u32 memory_size, fw_dump_len = 0;
+	int size = 0;
 
 	card = sdio_get_drvdata(func);
 	priv = card->priv;
@@ -1478,7 +1479,7 @@ done:
 	if (fw_dump_len == 0)
 		return;
 
-	fw_dump_data = vzalloc(fw_dump_len+1);
+	fw_dump_data = vzalloc(fw_dump_len + 1);
 	if (!fw_dump_data) {
 		BT_ERR("Vzalloc fw_dump_data fail!");
 		return;
@@ -1493,20 +1494,18 @@ done:
 		struct memory_type_mapping *entry = &mem_type_mapping_tbl[idx];
 
 		if (entry->mem_ptr) {
-			strcpy(fw_dump_ptr, "========Start dump ");
-			fw_dump_ptr += strlen("========Start dump ");
-
-			strcpy(fw_dump_ptr, entry->mem_name);
-			fw_dump_ptr += strlen(entry->mem_name);
-
-			strcpy(fw_dump_ptr, "========\n");
-			fw_dump_ptr += strlen("========\n");
-
-			memcpy(fw_dump_ptr, entry->mem_ptr, entry->mem_size);
-			fw_dump_ptr += entry->mem_size;
-
-			strcpy(fw_dump_ptr, "\n========End dump========\n");
-			fw_dump_ptr += strlen("\n========End dump========\n");
+			size += scnprintf(fw_dump_ptr + size,
+					  fw_dump_len + 1 - size,
+					  "========Start dump %s========\n",
+					  entry->mem_name);
+
+			memcpy(fw_dump_ptr + size, entry->mem_ptr,
+			       entry->mem_size);
+			size += entry->mem_size;
+
+			size += scnprintf(fw_dump_ptr + size,
+					  fw_dump_len + 1 - size,
+					  "\n========End dump========\n");
 
 			vfree(mem_type_mapping_tbl[idx].mem_ptr);
 			mem_type_mapping_tbl[idx].mem_ptr = NULL;