| Message ID | alpine.LNX.2.00.1208072354030.3227@swampdragon.chaosbits.net |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
Le mercredi 8 août 2012 00:56:26 Jesper Juhl, vous avez écrit : > We allocate memory for 'req' with usb_alloc_urb() and then test > 'if (!req || rx_submit(pnd, req, GFP_KERNEL | __GFP_COLD))'. > If we enter that branch due to '!req' then there is no problem. But if > we enter the branch due to 'req' being != 0 and the 'rx_submit()' call > being false, then we'll leak the memory we allocated. > Deal with the leak by always calling 'usb_free_urb(req)' when entering > the branch. If 'req' happens to be 0 then the call is harmless, if it > is not 0 then we free the memory we allocated but don't need. > > Signed-off-by: Jesper Juhl <jj@chaosbits.net> Acked-by: Rémi Denis-Courmont <remi@remlab.net> > --- > drivers/net/usb/cdc-phonet.c | 1 + > 1 file changed, 1 insertion(+) > > Only compile tested due to lack of hardware. Hardware won't help you much with testing the error case anyway.
From: "Rémi Denis-Courmont" <remi@remlab.net> Date: Wed, 8 Aug 2012 10:12:06 +0300 > Le mercredi 8 août 2012 00:56:26 Jesper Juhl, vous avez écrit : >> We allocate memory for 'req' with usb_alloc_urb() and then test >> 'if (!req || rx_submit(pnd, req, GFP_KERNEL | __GFP_COLD))'. >> If we enter that branch due to '!req' then there is no problem. But if >> we enter the branch due to 'req' being != 0 and the 'rx_submit()' call >> being false, then we'll leak the memory we allocated. >> Deal with the leak by always calling 'usb_free_urb(req)' when entering >> the branch. If 'req' happens to be 0 then the call is harmless, if it >> is not 0 then we free the memory we allocated but don't need. >> >> Signed-off-by: Jesper Juhl <jj@chaosbits.net> > > Acked-by: Rémi Denis-Courmont <remi@remlab.net> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/usb/cdc-phonet.c b/drivers/net/usb/cdc-phonet.c index 6461004..7d78669 100644 --- a/drivers/net/usb/cdc-phonet.c +++ b/drivers/net/usb/cdc-phonet.c @@ -232,6 +232,7 @@ static int usbpn_open(struct net_device *dev) struct urb *req = usb_alloc_urb(0, GFP_KERNEL); if (!req || rx_submit(pnd, req, GFP_KERNEL | __GFP_COLD)) { + usb_free_urb(req); usbpn_close(dev); return -ENOMEM; }
We allocate memory for 'req' with usb_alloc_urb() and then test 'if (!req || rx_submit(pnd, req, GFP_KERNEL | __GFP_COLD))'. If we enter that branch due to '!req' then there is no problem. But if we enter the branch due to 'req' being != 0 and the 'rx_submit()' call being false, then we'll leak the memory we allocated. Deal with the leak by always calling 'usb_free_urb(req)' when entering the branch. If 'req' happens to be 0 then the call is harmless, if it is not 0 then we free the memory we allocated but don't need. Signed-off-by: Jesper Juhl <jj@chaosbits.net> --- drivers/net/usb/cdc-phonet.c | 1 + 1 file changed, 1 insertion(+) Only compile tested due to lack of hardware.