[PATCH 4.19 21/79] staging: rtl8712: fix use after free bugs

Greg Kroah-Hartman
2022-09-13T15:07:56Z

From: Dan Carpenter <dan.carpenter@oracle.com>

commit e230a4455ac3e9b112f0367d1b8e255e141afae0 upstream.

_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: 2865d42c78a9 ("staging: r8712u: Add the new driver to the mainline kernel")
Cc: stable <stable@kernel.org>
Reported-by: Zheng Wang <hackerzheng666@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/Yw4ASqkYcUhUfoY2@kili
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/staging/rtl8712/rtl8712_cmd.c | 36 ----------------------------------
1 file changed, 36 deletions(-)

--- a/drivers/staging/rtl8712/rtl8712_cmd.c
+++ b/drivers/staging/rtl8712/rtl8712_cmd.c
@@ -129,34 +129,6 @@ static void r871x_internal_cmd_hdl(struc
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;
@@ -225,14 +197,6 @@ static struct cmd_obj *cmd_hdl_filter(st
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;