[PATCH] isdn/eicon: do integrity check on cmd->adapter == a->controller early
From: Meng Xu <hidden>
Date: 2017-09-24 15:14:59
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 <redacted>
---
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