From: Zong-Zhe Yang <kevin_yang@xxxxxxxxxxx>
Kernel logs on platform enabling SECURITY_LOADPIN_ENFORCE
------
```
LoadPin: firmware old-api-denied obj=<unknown> pid=810 cmdline="modprobe -q -- rtw89_8852ce"
rtw89_8852ce 0000:01:00.0: loading /lib/firmware/rtw89/rtw8852c_fw.bin failed with error -1
rtw89_8852ce 0000:01:00.0: Direct firmware load for rtw89/rtw8852c_fw.bin failed with error -1
rtw89_8852ce 0000:01:00.0: failed to early request firmware: -1
```
Trace
------
```
request_partial_firmware_into_buf()
> _request_firmware()
>> fw_get_filesystem_firmware()
>>> kernel_read_file_from_path_initns()
>>>> kernel_read_file()
>>>>> security_kernel_read_file()
// It will iterate enabled LSMs' hooks for kernel_read_file.
// With loadpin, it hooks loadpin_read_file.
```
If SECURITY_LOADPIN_ENFORCE is enabled, doing kernel_read_file() on partial
files will be denied and return -EPERM (-1). Then, the outer API based on it,
e.g. request_partial_firmware_into_buf(), will get the error.
In the case, we cannot get the firmware stuffs right, even though there might
be no error other than a permission issue on reading a partial file. So we have
to request full firmware if SECURITY_LOADPIN_ENFORCE is enabled. It makes us
still have a chance to do early firmware work on this kind of platforms.
Signed-off-by: Zong-Zhe Yang <kevin_yang@xxxxxxxxxxx>
Signed-off-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx>
---
drivers/net/wireless/realtek/rtw89/fw.c | 30 +++++++++++++++++--------
drivers/net/wireless/realtek/rtw89/fw.h | 15 +++++++++++++
2 files changed, 36 insertions(+), 9 deletions(-)
diff --git a/drivers/net/wireless/realtek/rtw89/fw.c b/drivers/net/wireless/realtek/rtw89/fw.c
index 7e682709232d7..f5daea0d4f93c 100644
--- a/drivers/net/wireless/realtek/rtw89/fw.c
+++ b/drivers/net/wireless/realtek/rtw89/fw.c
@@ -277,25 +277,37 @@ void rtw89_early_fw_feature_recognize(struct device *device,
const struct rtw89_chip_info *chip,
u32 *early_feat_map)
{
- union {
- struct rtw89_mfw_hdr mfw_hdr;
- u8 fw_hdr[RTW89_FW_HDR_SIZE];
- } buf = {};
+ union rtw89_compat_fw_hdr buf = {};
const struct firmware *firmware;
+ bool full_req = false;
u32 ver_code;
int ret;
int i;
- ret = request_partial_firmware_into_buf(&firmware, chip->fw_name,
- device, &buf, sizeof(buf), 0);
+ /* If SECURITY_LOADPIN_ENFORCE is enabled, reading partial files will
+ * be denied (-EPERM). Then, we don't get right firmware things as
+ * expected. So, in this case, we have to request full firmware here.
+ */
+ if (IS_ENABLED(CONFIG_SECURITY_LOADPIN_ENFORCE))
+ full_req = true;
+
+ if (full_req)
+ ret = request_firmware(&firmware, chip->fw_name, device);
+ else
+ ret = request_partial_firmware_into_buf(&firmware, chip->fw_name,
+ device, &buf, sizeof(buf),
+ 0);
+
if (ret) {
dev_err(device, "failed to early request firmware: %d\n", ret);
return;
}
- ver_code = buf.mfw_hdr.sig != RTW89_MFW_SIG ?
- RTW89_FW_HDR_VER_CODE(&buf.fw_hdr) :
- RTW89_MFW_HDR_VER_CODE(&buf.mfw_hdr);
+ if (full_req)
+ ver_code = rtw89_compat_fw_hdr_ver_code(firmware->data);
+ else
+ ver_code = rtw89_compat_fw_hdr_ver_code(&buf);
+
if (!ver_code)
goto out;
diff --git a/drivers/net/wireless/realtek/rtw89/fw.h b/drivers/net/wireless/realtek/rtw89/fw.h
index 46d57414f24e2..5c4c7de1b4f5d 100644
--- a/drivers/net/wireless/realtek/rtw89/fw.h
+++ b/drivers/net/wireless/realtek/rtw89/fw.h
@@ -3291,6 +3291,21 @@ struct fwcmd_hdr {
__le32 hdr1;
};
+union rtw89_compat_fw_hdr {
+ struct rtw89_mfw_hdr mfw_hdr;
+ u8 fw_hdr[RTW89_FW_HDR_SIZE];
+};
+
+static inline u32 rtw89_compat_fw_hdr_ver_code(const void *fw_buf)
+{
+ const union rtw89_compat_fw_hdr *compat = (typeof(compat))fw_buf;
+
+ if (compat->mfw_hdr.sig == RTW89_MFW_SIG)
+ return RTW89_MFW_HDR_VER_CODE(&compat->mfw_hdr);
+ else
+ return RTW89_FW_HDR_VER_CODE(&compat->fw_hdr);
+}
+
#define RTW89_H2C_RF_PAGE_SIZE 500
#define RTW89_H2C_RF_PAGE_NUM 3
struct rtw89_fw_h2c_rf_reg_info {
--
2.25.1
