[PATCH 47/69] isdn: mISDN: correctly handle ph_info allocation failure in hfcsusb_ph_info

Greg Kroah-Hartman
2021-05-03T12:01:18Z

From: Phillip Potter <phil@philpotter.co.uk>

Modify return type of hfcusb_ph_info to int, so that we can pass error
value up the call stack when allocation of ph_info fails. Also change
three of four call sites to actually account for the memory failure.
The fourth, in ph_state_nt, is infeasible to change as it is in turn
called by ph_state which is used as a function pointer argument to
mISDN_initdchannel, which would necessitate changing its signature
and updating all the places where it is used (too many).

Fixes original flawed commit (38d22659803a) from the University of
Minnesota.

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/isdn/hardware/mISDN/hfcsusb.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/isdn/hardware/mISDN/hfcsusb.c b/drivers/isdn/hardware/mISDN/hfcsusb.c
index 4bb470d3963d..cd5642cef01f 100644
--- a/drivers/isdn/hardware/mISDN/hfcsusb.c
+++ b/drivers/isdn/hardware/mISDN/hfcsusb.c
@@ -46,7 +46,7 @@ static void hfcsusb_start_endpoint(struct hfcsusb *hw, int channel);
static void hfcsusb_stop_endpoint(struct hfcsusb *hw, int channel);
static int hfcsusb_setup_bch(struct bchannel *bch, int protocol);
static void deactivate_bchannel(struct bchannel *bch);
-static void hfcsusb_ph_info(struct hfcsusb *hw);
+static int hfcsusb_ph_info(struct hfcsusb *hw);

/* start next background transfer for control channel */
static void
@@ -241,7 +241,7 @@ hfcusb_l2l1B(struct mISDNchannel *ch, struct sk_buff *skb)
* send full D/B channel status information
* as MPH_INFORMATION_IND
*/
-static void
+static int
hfcsusb_ph_info(struct hfcsusb *hw)
{
struct ph_info *phi;
@@ -249,6 +249,9 @@ hfcsusb_ph_info(struct hfcsusb *hw)
int i;

phi = kzalloc(struct_size(phi, bch, dch->dev.nrbchan), GFP_ATOMIC);
+ if (!phi)
+ return -ENOMEM;
+
phi->dch.ch.protocol = hw->protocol;
phi->dch.ch.Flags = dch->Flags;
phi->dch.state = dch->state;
@@ -260,6 +263,8 @@ hfcsusb_ph_info(struct hfcsusb *hw)
_queue_data(&dch->dev.D, MPH_INFORMATION_IND, MISDN_ID_ANY,
struct_size(phi, bch, dch->dev.nrbchan), phi, GFP_ATOMIC);
kfree(phi);
+
+ return 0;
}

/*
@@ -344,8 +349,7 @@ hfcusb_l2l1D(struct mISDNchannel *ch, struct sk_buff *skb)
ret = l1_event(dch->l1, hh->prim);
break;
case MPH_INFORMATION_REQ:
- hfcsusb_ph_info(hw);
- ret = 0;
+ ret = hfcsusb_ph_info(hw);
break;
}

@@ -400,8 +404,7 @@ hfc_l1callback(struct dchannel *dch, u_int cmd)
hw->name, __func__, cmd);
return -1;
}
- hfcsusb_ph_info(hw);
- return 0;
+ return hfcsusb_ph_info(hw);
}

static int
@@ -743,8 +746,7 @@ hfcsusb_setup_bch(struct bchannel *bch, int protocol)
handle_led(hw, (bch->nr == 1) ? LED_B1_OFF :
LED_B2_OFF);
}
- hfcsusb_ph_info(hw);
- return 0;
+ return hfcsusb_ph_info(hw);
}

static void
--
2.31.1