staging: rtl8712: fix use after free bugs

stable inclusion
from stable-v5.10.142
commit 19e3f69d19801940abc2ac37c169882769ed9770
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I63OIO
CVE: CVE-2022-4095

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=19e3f69d19801940abc2ac37c169882769ed9770

--------------------------------

_Read/Write_MACREG callbacks are NULL so the read/write_macreg_hdl()
functions don't do anything except free the "pcmd" pointer.  It
results in a use after free.  Delete them.

Fixes: 2865d42c ("staging: r8712u: Add the new driver to the mainline kernel")
Cc: stable <stable@kernel.org>
Reported-by: NZheng Wang <hackerzheng666@gmail.com>
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/Yw4ASqkYcUhUfoY2@kiliSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NGuan Jing <guanjing6@huawei.com>
Reviewed-by: NZhang Qiao <zhangqiao22@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/staging/rtl8712/rtl8712_cmd.c

@@ -117,34 +117,6 @@ static void r871x_internal_cmd_hdl(struct _adapter *padapter, u8 *pbuf)
 	kfree(pdrvcmd->pbuf);
 }
 
-static u8 read_macreg_hdl(struct _adapter *padapter, u8 *pbuf)
-{
-	void (*pcmd_callback)(struct _adapter *dev, struct cmd_obj	*pcmd);
-	struct cmd_obj *pcmd  = (struct cmd_obj *)pbuf;
-
-	/*  invoke cmd->callback function */
-	pcmd_callback = cmd_callback[pcmd->cmdcode].callback;
-	if (!pcmd_callback)
-		r8712_free_cmd_obj(pcmd);
-	else
-		pcmd_callback(padapter, pcmd);
-	return H2C_SUCCESS;
-}
-
-static u8 write_macreg_hdl(struct _adapter *padapter, u8 *pbuf)
-{
-	void (*pcmd_callback)(struct _adapter *dev, struct cmd_obj	*pcmd);
-	struct cmd_obj *pcmd  = (struct cmd_obj *)pbuf;
-
-	/*  invoke cmd->callback function */
-	pcmd_callback = cmd_callback[pcmd->cmdcode].callback;
-	if (!pcmd_callback)
-		r8712_free_cmd_obj(pcmd);
-	else
-		pcmd_callback(padapter, pcmd);
-	return H2C_SUCCESS;
-}
-
 static u8 read_bbreg_hdl(struct _adapter *padapter, u8 *pbuf)
 {
 	struct cmd_obj *pcmd  = (struct cmd_obj *)pbuf;
@@ -213,14 +185,6 @@ static struct cmd_obj *cmd_hdl_filter(struct _adapter *padapter,
 	pcmd_r = NULL;
 
 	switch (pcmd->cmdcode) {
-	case GEN_CMD_CODE(_Read_MACREG):
-		read_macreg_hdl(padapter, (u8 *)pcmd);
-		pcmd_r = pcmd;
-		break;
-	case GEN_CMD_CODE(_Write_MACREG):
-		write_macreg_hdl(padapter, (u8 *)pcmd);
-		pcmd_r = pcmd;
-		break;
 	case GEN_CMD_CODE(_Read_BBREG):
 		read_bbreg_hdl(padapter, (u8 *)pcmd);
 		break;