[PATCH] rtw89: Fix crash by loading compressed firmware file

[Takashi Iwai]

When a firmware is loaded in the compressed format or via user-mode
helper, it's mapped in read-only, and the rtw89 driver crashes at
rtw89_fw_download() when it tries to modify some data.

This patch is an attemp to avoid the crash by re-allocating the data
via vmalloc() for the data modification.

Buglink: https://bugzilla.opensuse.org/show_bug.cgi?id=1188303
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>

---
 drivers/net/wireless/realtek/rtw89/core.h |  3 ++-
 drivers/net/wireless/realtek/rtw89/fw.c   | 15 ++++++++++-----
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw89/core.h b/drivers/net/wireless/realtek/rtw89/core.h
index c2885e4dd882..048855e05697 100644
--- a/drivers/net/wireless/realtek/rtw89/core.h
+++ b/drivers/net/wireless/realtek/rtw89/core.h
@@ -2309,7 +2309,8 @@ struct rtw89_fw_suit {
 	RTW89_FW_VER_CODE((s)->major_ver, (s)->minor_ver, (s)->sub_ver, (s)->sub_idex)
 
 struct rtw89_fw_info {
-	const struct firmware *firmware;
+	const void *firmware;
+	size_t firmware_size;
 	struct rtw89_dev *rtwdev;
 	struct completion completion;
 	u8 h2c_seq;
diff --git a/drivers/net/wireless/realtek/rtw89/fw.c b/drivers/net/wireless/realtek/rtw89/fw.c
index 212aaf577d3c..b59fecaeea25 100644
--- a/drivers/net/wireless/realtek/rtw89/fw.c
+++ b/drivers/net/wireless/realtek/rtw89/fw.c
@@ -124,8 +124,8 @@ int rtw89_mfw_recognize(struct rtw89_dev *rtwdev, enum rtw89_fw_type type,
 			struct rtw89_fw_suit *fw_suit)
 {
 	struct rtw89_fw_info *fw_info = &rtwdev->fw;
-	const u8 *mfw = fw_info->firmware->data;
-	u32 mfw_len = fw_info->firmware->size;
+	const u8 *mfw = fw_info->firmware;
+	u32 mfw_len = fw_info->firmware_size;
 	const struct rtw89_mfw_hdr *mfw_hdr = (const struct rtw89_mfw_hdr *)mfw;
 	const struct rtw89_mfw_info *mfw_info;
 	int i;
@@ -489,7 +489,10 @@ static void rtw89_load_firmware_cb(const struct firmware *firmware, void *contex
 		return;
 	}
 
-	fw->firmware = firmware;
+	fw->firmware = vmalloc(firmware->size);
+	if (fw->firmware)
+		memcpy((void *)fw->firmware, firmware->data, firmware->size);
+	release_firmware(firmware);
 	complete_all(&fw->completion);
 }
 
@@ -518,8 +521,10 @@ void rtw89_unload_firmware(struct rtw89_dev *rtwdev)
 
 	rtw89_wait_firmware_completion(rtwdev);
 
-	if (fw->firmware)
-		release_firmware(fw->firmware);
+	if (fw->firmware) {
+		vfree(fw->firmware);
+		fw->firmware = NULL;
+	}
 }
 
 #define H2C_CAM_LEN 60
-- 
2.26.2