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path: root/drivers/net/xen-netback/netback.c
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2013-02-28xen-netback: correctly return errors from netbk_count_requests()David Vrabel
[ Upstream commit 35876b5ffc154c357476b2c3bdab10feaf4bd8f0 ] netbk_count_requests() could detect an error, call netbk_fatal_tx_error() but return 0. The vif may then be used afterwards (e.g., in a call to netbk_tx_error(). Since netbk_fatal_tx_error() could set vif->refcnt to 1, the vif may be freed immediately after the call to netbk_fatal_tx_error() (e.g., if the vif is also removed). Netback thread Xenwatch thread ------------------------------------------- netbk_fatal_tx_err() netback_remove() xenvif_disconnect() ... free_netdev() netbk_tx_err() Oops! Signed-off-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: Jan Beulich <JBeulich@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reported-by: Christopher S. Aker <caker@theshore.net> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-28xen/netback: check correct frag when looking for head fragIan Campbell
When I backported 7d5145d8eb2b "xen/netback: don't leak pages on failure in xen_netbk_tx_check_gop" to 3.0 (where it became f0457844e605) I somehow picked up an extraneous hunk breaking this. Reported-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-14netback: correct netbk_tx_err to handle wrap around.Ian Campbell
[ Upstream commit b9149729ebdcfce63f853aa54a404c6a8f6ebbf3 ] Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Jan Beulich <JBeulich@suse.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-14xen/netback: free already allocated memory on failure in xen_netbk_get_requestsIan Campbell
[ Upstream commit 4cc7c1cb7b11b6f3515bd9075527576a1eecc4aa ] Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-14xen/netback: don't leak pages on failure in xen_netbk_tx_check_gop.Matthew Daley
[ Upstream commit 7d5145d8eb2b9791533ffe4dc003b129b9696c48 ] Signed-off-by: Matthew Daley <mattjd@gmail.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Jan Beulich <JBeulich@suse.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-14xen/netback: shutdown the ring if it contains garbage.Ian Campbell
[ Upstream commit 48856286b64e4b66ec62b94e504d0b29c1ade664 ] A buggy or malicious frontend should not be able to confuse netback. If we spot anything which is not as it should be then shutdown the device and don't try to continue with the ring in a potentially hostile state. Well behaved and non-hostile frontends will not be penalised. As well as making the existing checks for such errors fatal also add a new check that ensures that there isn't an insane number of requests on the ring (i.e. more than would fit in the ring). If the ring contains garbage then previously is was possible to loop over this insane number, getting an error each time and therefore not generating any more pending requests and therefore not exiting the loop in xen_netbk_tx_build_gops for an externded period. Also turn various netdev_dbg calls which no precipitate a fatal error into netdev_err, they are rate limited because the device is shutdown afterwards. This fixes at least one known DoS/softlockup of the backend domain. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Jan Beulich <JBeulich@suse.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2011-03-15xen network backend driverIan Campbell
netback is the host side counterpart to the frontend driver in drivers/net/xen-netfront.c. The PV protocol is also implemented by frontend drivers in other OSes too, such as the BSDs and even Windows. The patch is based on the driver from the xen.git pvops kernel tree but has been put through the checkpatch.pl wringer plus several manual cleanup passes and review iterations. The driver has been moved from drivers/xen/netback to drivers/net/xen-netback. One major change from xen.git is that the guest transmit path (i.e. what looks like receive to netback) has been significantly reworked to remove the dependency on the out of tree PageForeign page flag (a core kernel patch which enables a per page destructor callback on the final put_page). This page flag was used in order to implement a grant map based transmit path (where guest pages are mapped directly into SKB frags). Instead this version of netback uses grant copy operations into regular memory belonging to the backend domain. Reinstating the grant map functionality is something which I would like to revisit in the future. Note that this driver depends on 2e820f58f7ad "xen/irq: implement bind_interdomain_evtchn_to_irqhandler for backend drivers" which is in linux next via the "xen-two" tree and is intended for the 2.6.39 merge window: git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/backends this branch has only that single commit since 2.6.38-rc2 and is safe for cross merging into the net branch. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>