HI Gustavo, > -----Original Message----- > From: Malovany, Ram > Sent: Wednesday, July 25, 2012 11:01 AM > To: 'Gustavo Padovan' > Cc: linux-bluetooth@xxxxxxxxxxxxxxx > Subject: RE: [PATCH] Bluetooth: Fix for double free of st buffer. > > HI Gustavo, > > > -----Original Message----- > > From: Gustavo Padovan [mailto:gustavo@xxxxxxxxxxx] > > Sent: Wednesday, July 25, 2012 2:01 AM > > To: Malovany, Ram > > Cc: linux-bluetooth@xxxxxxxxxxxxxxx > > Subject: Re: [PATCH] Bluetooth: Fix for double free of st buffer. > > > > Hi Ram, > > > > * ramm@xxxxxx <ramm@xxxxxx> [2012-07-17 10:49:30 +0300]: > > > > > From: Ram Malovany <ramm@xxxxxx> > > > > > > When the Shared Transport line discipline driver (st_core) get data it > > > pushes the skb received to the relevant protocol stacks , it then > > > excepts that the relevant protocol stacks should handle the buffer , > > > and if it cannot then the stack should respond with an error. > > > In our case the Bluetooth driver for shared transport (btwilink) should > > > always be able to handle the buffer , in case of an error it will > > > release it , thus we always should return 0. > > > > > > Signed-off-by: Ram Malovany <ramm@xxxxxx> > > > --- > > > drivers/bluetooth/btwilink.c | 12 ++++++++---- > > > 1 files changed, 8 insertions(+), 4 deletions(-) > > > > > > diff --git a/drivers/bluetooth/btwilink.c b/drivers/bluetooth/btwilink.c > > > index 8869469..1f60d84 100644 > > > --- a/drivers/bluetooth/btwilink.c > > > +++ b/drivers/bluetooth/btwilink.c > > > @@ -94,18 +94,22 @@ static void st_reg_completion_cb(void *priv_data, char > > data) > > > } > > > > > > /* Called by Shared Transport layer when receive data is > > > - * available */ > > > + * available > > > + * Return: > > > + * 0 if buffer handled (affectivly allways even if error found) > > > + * if return !=0 the buffer will be freed by the st > > > + */ > > > static long st_receive(void *priv_data, struct sk_buff *skb) > > > { > > > struct ti_st *lhst = priv_data; > > > int err; > > > > > > if (!skb) > > > - return -EFAULT; > > > + return 0; > > > > > > if (!lhst) { > > > kfree_skb(skb); > > > > If you remove this call to kfree_skb() from here doesn't it fixes your > > problem? > > > > Gustavo I looked at the fix again , and I think we shouldn't change it since the main problem that I am observing her is not the kfree_skb() at this point , The problem is related to who is in charge of the buffer at this point , and in our case the function hci_recv_frame() can use different transports and upon an error it will free the buffer as well , in my fix I made sure that st_receive() will always take care of the buffer. > > You are correct , I was going to send a new version for this patch. > > Thanks, > Ram -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
