Bluetooth: btqca: Don't modify firmware contents in-place

struct firmware::data is marked const, and when the firmware is
compressed with xz (default at least with Fedora) it's mapped read-only
which results in a crash:

BUG: unable to handle page fault for address: ffffae57c0ca5047
PGD 100000067 P4D 100000067 PUD 1001ce067 PMD 10165a067 PTE 8000000112bba161
Oops: 0003 [#1] SMP NOPTI
CPU: 3 PID: 204 Comm: kworker/u17:0 Not tainted 5.12.1-test+ #1
Hardware name: Dell Inc. XPS 13 9310/0F7M4C, BIOS 1.2.5 12/10/2020
Workqueue: hci0 hci_power_on [bluetooth]
RIP: 0010:qca_download_firmware+0x27c/0x4e0 [btqca]
Code: 1b 75 04 80 48 0c 01 0f b7 c6 8d 54 02 0c 41 39 d7 0f 8e 62 fe ff ff 48 63 c2 4c 01 e8 0f b7 38 0f b7 70 02 66 83 ff 11 75 d3 <80> 48 0c 80 41 83 fc 03 7e 6e 88 58 0d eb ce 41 0f b6 45 0e 48 8b
RSP: 0018:ffffae57c08dfc68 EFLAGS: 00010246
RAX: ffffae57c0ca503b RBX: 000000000000000e RCX: 0000000000000000
RDX: 0000000000000037 RSI: 0000000000000006 RDI: 0000000000000011
RBP: ffff978d9949e000 R08: ffff978d84ed7540 R09: ffffae57c0ca5000
R10: 000000000010cd00 R11: 0000000000000001 R12: 0000000000000005
R13: ffffae57c0ca5004 R14: ffff978d98ca8680 R15: 00000000000016a9
FS:  0000000000000000(0000) GS:ffff9794ef6c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffae57c0ca5047 CR3: 0000000113d5a004 CR4: 0000000000770ee0
PKRU: 55555554
Call Trace:
 qca_uart_setup+0x2cb/0x1390 [btqca]
 ? qca_read_soc_version+0x136/0x220 [btqca]
 qca_setup+0x288/0xab0 [hci_uart]
 hci_dev_do_open+0x1f3/0x780 [bluetooth]
 ? try_to_wake_up+0x1c1/0x4f0
 hci_power_on+0x3f/0x200 [bluetooth]
 process_one_work+0x1ec/0x380
 worker_thread+0x53/0x3e0
 ? process_one_work+0x380/0x380
 kthread+0x11b/0x140
 ? kthread_associate_blkcg+0xa0/0xa0
 ret_from_fork+0x1f/0x30
Modules linked in: llc ip_set nf_tables nfnetlink snd_soc_skl_hda_dsp(+) ip6table_filter snd_soc_hdac_hdmi ip6_tables qrtr_mhi iptable_filter snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic s>
 dell_wmi_sysman(+) dell_smbios snd dcdbas mhi vfat videobuf2_vmalloc i2c_i801 videobuf2_memops videobuf2_v4l2 dell_wmi_descriptor fat wmi_bmof soundcore i2c_smbus videobuf2_common libarc4 mei_me mei hid_se>
 i2c_hid_acpi i2c_hid video pinctrl_tigerlake fuse
CR2: ffffae57c0ca5047

This also seems to fix a failure to suspend due to the firmware
download on bootup getting interrupted by the crash:

Bluetooth: hci0: SSR or FW download time out
PM: dpm_run_callback(): acpi_subsys_suspend+0x0/0x60 returns -110
PM: Device serial0-0 failed to suspend: error -110
PM: Some devices failed to suspend, or early wake event detected

Fixes: 83e81961 ("Bluetooth: btqca: Introduce generic QCA ROME support")
Cc: Venkata Lakshmi Narayana Gubba <gubbaven@codeaurora.org>
Cc: stable@vger.kernel.org
Signed-off-by: Connor Abbott <cwabbott0@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/btqca.c

@@ -183,7 +183,7 @@ int qca_send_pre_shutdown_cmd(struct hci_dev *hdev)
 EXPORT_SYMBOL_GPL(qca_send_pre_shutdown_cmd);
 
 static void qca_tlv_check_data(struct qca_fw_config *config,
-		const struct firmware *fw, enum qca_btsoc_type soc_type)
+		u8 *fw_data, enum qca_btsoc_type soc_type)
 {
 	const u8 *data;
 	u32 type_len;
@@ -194,7 +194,7 @@ static void qca_tlv_check_data(struct qca_fw_config *config,
 	struct tlv_type_nvm *tlv_nvm;
 	uint8_t nvm_baud_rate = config->user_baud_rate;
 
-	tlv = (struct tlv_type_hdr *)fw->data;
+	tlv = (struct tlv_type_hdr *)fw_data;
 
 	type_len = le32_to_cpu(tlv->type_len);
 	length = (type_len >> 8) & 0x00ffffff;
@@ -390,8 +390,9 @@ static int qca_download_firmware(struct hci_dev *hdev,
 				 enum qca_btsoc_type soc_type)
 {
 	const struct firmware *fw;
+	u8 *data;
 	const u8 *segment;
-	int ret, remain, i = 0;
+	int ret, size, remain, i = 0;
 
 	bt_dev_info(hdev, "QCA Downloading %s", config->fwname);
 
@@ -402,10 +403,22 @@ static int qca_download_firmware(struct hci_dev *hdev,
 		return ret;
 	}
 
-	qca_tlv_check_data(config, fw, soc_type);
+	size = fw->size;
+	data = vmalloc(fw->size);
+	if (!data) {
+		bt_dev_err(hdev, "QCA Failed to allocate memory for file: %s",
+			   config->fwname);
+		release_firmware(fw);
+		return -ENOMEM;
+	}
+
+	memcpy(data, fw->data, size);
+	release_firmware(fw);
+
+	qca_tlv_check_data(config, data, soc_type);
 
-	segment = fw->data;
-	remain = fw->size;
+	segment = data;
+	remain = size;
 	while (remain > 0) {
 		int segsize = min(MAX_SIZE_PER_TLV_SEGMENT, remain);
 
@@ -435,7 +448,7 @@ static int qca_download_firmware(struct hci_dev *hdev,
 		ret = qca_inject_cmd_complete_event(hdev);
 
 out:
-	release_firmware(fw);
+	vfree(data);
 
 	return ret;
 }