In my understanding, the reason to have the check on
if (cmd->adapter != a->controller) {report error} is to prevent the case
where after xdi_copy_from_user() in diva_xdi_write(), data->adapter
is changed from what is previously fetched in diva_xdi_open_adapter(),
and hence, leading to using a wrong adapter to do interface.cmd_proc().
Although respective checks are in place in the three implementations of
cmd_proc(), i.e., diva_4bri_cmd_card_proc(), diva_bri_cmd_card_proc(),
and diva_pri_cmd_card_proc(), in my opinion, a better way might be doing
this integrity right after the xdi_copy_from_user() in diva_xdi_write(),
which is what this patch is for.
Signed-off-by: Meng Xu <mengxu.gat...@gmail.com>
---
drivers/isdn/hardware/eicon/diva.c | 10 +++++++++-
drivers/isdn/hardware/eicon/os_4bri.c | 6 ------
drivers/isdn/hardware/eicon/os_bri.c | 6 ------
drivers/isdn/hardware/eicon/os_pri.c | 6 ------
4 files changed, 9 insertions(+), 19 deletions(-)
diff --git a/drivers/isdn/hardware/eicon/diva.c
b/drivers/isdn/hardware/eicon/diva.c
index d91dd58..8ebd3c7 100644
--- a/drivers/isdn/hardware/eicon/diva.c
+++ b/drivers/isdn/hardware/eicon/diva.c
@@ -460,7 +460,15 @@ diva_xdi_write(void *adapter, void *os_handle, const void
__user *src,
length = (*cp_fn) (os_handle, data, src, length);
if (length > 0) {
- if ((*(a->interface.cmd_proc))
+ /* do the integrity check early */
+ if(((diva_xdi_um_cfg_cmd_t *)data)->adapter != a->controller){
+ DBG_ERR(("A: A(%d) write, invalid controller=%d != %d",
+ ((diva_xdi_um_cfg_cmd_t
*)data)->adapter, a->controller));
+
+ length = -1;
+ }
+
+ else if ((*(a->interface.cmd_proc))
(a, (diva_xdi_um_cfg_cmd_t *) data, length)) {
length = -3;
}
diff --git a/drivers/isdn/hardware/eicon/os_4bri.c
b/drivers/isdn/hardware/eicon/os_4bri.c
index 1891246..adbd852 100644
--- a/drivers/isdn/hardware/eicon/os_4bri.c
+++ b/drivers/isdn/hardware/eicon/os_4bri.c
@@ -629,12 +629,6 @@ diva_4bri_cmd_card_proc(struct _diva_os_xdi_adapter *a,
{
int ret = -1;
- if (cmd->adapter != a->controller) {
- DBG_ERR(("A: 4bri_cmd, invalid controller=%d != %d",
- cmd->adapter, a->controller))
- return (-1);
- }
-
switch (cmd->command) {
case DIVA_XDI_UM_CMD_GET_CARD_ORDINAL:
a->xdi_mbox.data_length = sizeof(dword);
diff --git a/drivers/isdn/hardware/eicon/os_bri.c
b/drivers/isdn/hardware/eicon/os_bri.c
index 20f2653..e3d398f 100644
--- a/drivers/isdn/hardware/eicon/os_bri.c
+++ b/drivers/isdn/hardware/eicon/os_bri.c
@@ -398,12 +398,6 @@ diva_bri_cmd_card_proc(struct _diva_os_xdi_adapter *a,
{
int ret = -1;
- if (cmd->adapter != a->controller) {
- DBG_ERR(("A: pri_cmd, invalid controller=%d != %d",
- cmd->adapter, a->controller))
- return (-1);
- }
-
switch (cmd->command) {
case DIVA_XDI_UM_CMD_GET_CARD_ORDINAL:
a->xdi_mbox.data_length = sizeof(dword);
diff --git a/drivers/isdn/hardware/eicon/os_pri.c
b/drivers/isdn/hardware/eicon/os_pri.c
index da4957a..93443aa 100644
--- a/drivers/isdn/hardware/eicon/os_pri.c
+++ b/drivers/isdn/hardware/eicon/os_pri.c
@@ -604,12 +604,6 @@ diva_pri_cmd_card_proc(struct _diva_os_xdi_adapter *a,
{
int ret = -1;
- if (cmd->adapter != a->controller) {
- DBG_ERR(("A: pri_cmd, invalid controller=%d != %d",
- cmd->adapter, a->controller))
- return (-1);
- }
-
switch (cmd->command) {
case DIVA_XDI_UM_CMD_GET_CARD_ORDINAL:
a->xdi_mbox.data_length = sizeof(dword);
--
2.7.4
