staging: rtl8188eu: Fix two sleep-in-atomic-context bugs in rtw_chk_hi_queue_cmd()

usb_write_port_complete() in usb_ops_linux.c is a completion handler
function for the USB driver. So it should not sleep, but it is can sleep
according to the function call paths (from bottom to top) in Linux-4.16:

[FUNC] kzalloc(GFP_KERNEL)
drivers/staging/rtl8188eu/core/rtw_cmd.c, 1081:
	kzalloc in rtw_chk_hi_queue_cmd
drivers/staging/rtl8188eu/os_dep/usb_ops_linux.c, 604:
	rtw_chk_hi_queue_cmd in usb_write_port_complete

[FUNC] kzalloc(GFP_KERNEL)
drivers/staging/rtl8188eu/core/rtw_cmd.c, 1075:
	kzalloc in rtw_chk_hi_queue_cmd
drivers/staging/rtl8188eu/os_dep/usb_ops_linux.c, 604:
	rtw_chk_hi_queue_cmd in usb_write_port_complete

To fix these bugs, GFP_KERNEL is replaced with GFP_ATOMIC.

These bugs are found by my static analysis tool DSAC.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/rtl8188eu/core/rtw_cmd.c b/drivers/staging/rtl8188eu/core/rtw_cmd.c
index 59039211dad279c97fe6e2b430d7182f0f70c959..7f9536c55774cf5c263d2de8eac064f1898acaa3 100644 (file)
--- a/drivers/staging/rtl8188eu/core/rtw_cmd.c
+++ b/drivers/staging/rtl8188eu/core/rtw_cmd.c
@@ -1064,13 +1064,13 @@ u8 rtw_chk_hi_queue_cmd(struct adapter *padapter)
        struct cmd_priv *pcmdpriv = &padapter->cmdpriv;
        u8      res = _SUCCESS;
 
-       ph2c = kzalloc(sizeof(struct cmd_obj), GFP_KERNEL);
+       ph2c = kzalloc(sizeof(struct cmd_obj), GFP_ATOMIC);
        if (!ph2c) {
                res = _FAIL;
                goto exit;
        }
 
-       pdrvextra_cmd_parm = kzalloc(sizeof(struct drvextra_cmd_parm), GFP_KERNEL);
+       pdrvextra_cmd_parm = kzalloc(sizeof(struct drvextra_cmd_parm), GFP_ATOMIC);
        if (!pdrvextra_cmd_parm) {
                kfree(ph2c);
                res = _FAIL;