talos-obmc-linux/drivers/net/ipvlan, branch dev-4.13

tap: reference to KVA of an unloaded module causes kernel panic

2017-11-18T10:30:38+00:00

[ Upstream commit dea6e19f4ef746aa18b4c33d1a7fed54356796ed ] The commit 9a393b5d5988 ("tap: tap as an independent module") created a separate tap module that implements tap functionality and exports interfaces that will be used by macvtap and ipvtap modules to create create respective tap devices. However, that patch introduced a regression wherein the modules macvtap and ipvtap can be removed (through modprobe -r) while there are applications using the respective /dev/tapX devices. These applications cause kernel to hold reference to /dev/tapX through 'struct cdev macvtap_cdev' and 'struct cdev ipvtap_dev' defined in macvtap and ipvtap modules respectively. So, when the application is later closed the kernel panics because we are referencing KVA that is present in the unloaded modules. ----------8<------- Example ----------8<---------- $ sudo ip li add name mv0 link enp7s0 type macvtap $ sudo ip li show mv0 |grep mv0| awk -e '{print $1 $2}' 14:mv0@enp7s0: $ cat /dev/tap14 & $ lsmod |egrep -i 'tap|vlan' macvtap 16384 0 macvlan 24576 1 macvtap tap 24576 3 macvtap $ sudo modprobe -r macvtap $ fg cat /dev/tap14 ^C <...system panics...> BUG: unable to handle kernel paging request at ffffffffa038c500 IP: cdev_put+0xf/0x30 ----------8<-----------------8<---------- The fix is to set cdev.owner to the module that creates the tap device (either macvtap or ipvtap). With this set, the operations (in fs/char_dev.c) on char device holds and releases the module through cdev_get() and cdev_put() and will not allow the module to unload prematurely. Fixes: 9a393b5d5988ea4e (tap: tap as an independent module) Signed-off-by: Girish Moodalbail Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipvlan: Fix 64-bit statistics seqcount initialization

2017-08-02T03:06:07+00:00

On 32-bit hosts and with CONFIG_DEBUG_LOCK_ALLOC we should be seeing a lockdep splat indicating this seqcount is not correctly initialized, fix that by using the proper helper function: netdev_alloc_pcpu_stats(). Fixes: 2ad7bf363841 ("ipvlan: Initial check-in of the IPVLAN driver.") Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller

net: add netlink_ext_ack argument to rtnl_link_ops.validate

2017-06-27T03:13:22+00:00

Add support for extended error reporting. Signed-off-by: Matthias Schiffer Acked-by: David Ahern Signed-off-by: David S. Miller

net: add netlink_ext_ack argument to rtnl_link_ops.changelink

2017-06-27T03:13:22+00:00

Add support for extended error reporting. Signed-off-by: Matthias Schiffer Acked-by: David Ahern Signed-off-by: David S. Miller

net: add netlink_ext_ack argument to rtnl_link_ops.newlink

2017-06-27T03:13:21+00:00

Add support for extended error reporting. Signed-off-by: Matthias Schiffer Acked-by: David Ahern Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2017-06-15T15:59:32+00:00

The conflicts were two cases of overlapping changes in batman-adv and the qed driver. Signed-off-by: David S. Miller

Ipvlan should return an error when an address is already in use.

2017-06-09T16:26:07+00:00

The ipvlan code already knows how to detect when a duplicate address is about to be assigned to an ipvlan device. However, that failure is not propogated outward and leads to a silent failure. Introduce a validation step at ip address creation time and allow device drivers to register to validate the incoming ip addresses. The ipvlan code is the first consumer. If it detects an address in use, we can return an error to the user before beginning to commit the new ifa in the networking code. This can be especially useful if it is necessary to provision many ipvlans in containers. The provisioning software (or operator) can use this to detect situations where an ip address is unexpectedly in use. Signed-off-by: Krister Johansen Signed-off-by: David S. Miller

net: Fix inconsistent teardown and release of private netdev state.

2017-06-07T19:53:24+00:00

Network devices can allocate reasources and private memory using netdev_ops->ndo_init(). However, the release of these resources can occur in one of two different places. Either netdev_ops->ndo_uninit() or netdev->destructor(). The decision of which operation frees the resources depends upon whether it is necessary for all netdev refs to be released before it is safe to perform the freeing. netdev_ops->ndo_uninit() presumably can occur right after the NETDEV_UNREGISTER notifier completes and the unicast and multicast address lists are flushed. netdev->destructor(), on the other hand, does not run until the netdev references all go away. Further complicating the situation is that netdev->destructor() almost universally does also a free_netdev(). This creates a problem for the logic in register_netdevice(). Because all callers of register_netdevice() manage the freeing of the netdev, and invoke free_netdev(dev) if register_netdevice() fails. If netdev_ops->ndo_init() succeeds, but something else fails inside of register_netdevice(), it does call ndo_ops->ndo_uninit(). But it is not able to invoke netdev->destructor(). This is because netdev->destructor() will do a free_netdev() and then the caller of register_netdevice() will do the same. However, this means that the resources that would normally be released by netdev->destructor() will not be. Over the years drivers have added local hacks to deal with this, by invoking their destructor parts by hand when register_netdevice() fails. Many drivers do not try to deal with this, and instead we have leaks. Let's close this hole by formalizing the distinction between what private things need to be freed up by netdev->destructor() and whether the driver needs unregister_netdevice() to perform the free_netdev(). netdev->priv_destructor() performs all actions to free up the private resources that used to be freed by netdev->destructor(), except for free_netdev(). netdev->needs_free_netdev is a boolean that indicates whether free_netdev() should be done at the end of unregister_netdevice(). Now, register_netdevice() can sanely release all resources after ndo_ops->ndo_init() succeeds, by invoking both ndo_ops->ndo_uninit() and netdev->priv_destructor(). And at the end of unregister_netdevice(), we invoke netdev->priv_destructor() and optionally call free_netdev(). Signed-off-by: David S. Miller

ipvlan: use pernet operations and restrict l3s hooks to master netns

2017-04-25T14:43:22+00:00

commit 4fbae7d83c98c30efc ("ipvlan: Introduce l3s mode") added registration of netfilter hooks via nf_register_hooks(). This API provides the illusion of 'global' netfilter hooks by placing the hooks in all current and future network namespaces. In case of ipvlan the hook appears to be only needed in the namespace that contains the ipvlan master device (i.e., usually init_net), so placing them in all namespaces is not needed. This switches ipvlan driver to pernet operations, and then only registers hooks in namespaces where a ipvlan master device is set to l3s mode. Extra care has to be taken when the master device is moved to another namespace, as we might have to 'move' the netfilter hooks too. This is done by storing the namespace the ipvlan port was created in. On REGISTER event, do (un)register operations in the old/new namespaces. This will also allow removal of the nf_register_hooks() in a future patch. Cc: Mahesh Bandewar Signed-off-by: Florian Westphal Signed-off-by: David S. Miller

ipvtap: IP-VLAN based tap driver

2017-02-12T01:59:41+00:00

This patch adds a tap character device driver that is based on the IP-VLAN network interface, called ipvtap. An ipvtap device can be created in the same way as an ipvlan device, using 'type ipvtap', and then accessed using the tap user space interface. Signed-off-by: Sainath Grandhi Signed-off-by: David S. Miller