kernel/linux.git/drivers/net/vxlan.c, branch v4.19.112

vxlan: changelink: Fix handling of default remotes

2020-01-27T13:50:07+00:00

[ Upstream commit ce5e098f7a10b4bf8e948c12fa350320c5c3afad ] Default remotes are stored as FDB entries with an Ethernet address of 00:00:00:00:00:00. When a request is made to change a remote address of a VXLAN device, vxlan_changelink() first deletes the existing default remote, and then creates a new FDB entry. This works well as long as the list of default remotes matches exactly the configuration of a VXLAN remote address. Thus when the VXLAN device has a remote of X, there should be exactly one default remote FDB entry X. If the VXLAN device has no remote address, there should be no such entry. Besides using "ip link set", it is possible to manipulate the list of default remotes by using the "bridge fdb". It is therefore easy to break the above condition. Under such circumstances, the __vxlan_fdb_delete() call doesn't delete the FDB entry itself, but just one remote. The following vxlan_fdb_create() then creates a new FDB entry, leading to a situation where two entries exist for the address 00:00:00:00:00:00, each with a different subset of default remotes. An even more obvious breakage rooted in the same cause can be observed when a remote address is configured for a VXLAN device that did not have one before. In that case vxlan_changelink() doesn't remove any remote, and just creates a new FDB entry for the new address: $ ip link add name vx up type vxlan id 2000 dstport 4789 $ bridge fdb ap dev vx 00:00:00:00:00:00 dst 192.0.2.20 self permanent $ bridge fdb ap dev vx 00:00:00:00:00:00 dst 192.0.2.30 self permanent $ ip link set dev vx type vxlan remote 192.0.2.30 $ bridge fdb sh dev vx | grep 00:00:00:00:00:00 00:00:00:00:00:00 dst 192.0.2.30 self permanent <- new entry, 1 rdst 00:00:00:00:00:00 dst 192.0.2.20 self permanent <- orig. entry, 2 rdsts 00:00:00:00:00:00 dst 192.0.2.30 self permanent To fix this, instead of calling vxlan_fdb_create() directly, defer to vxlan_fdb_update(). That has logic to handle the duplicates properly. Additionally, it also handles notifications, so drop that call from changelink as well. Fixes: 0241b836732f ("vxlan: fix default fdb entry netlink notify ordering during netdev create") Signed-off-by: Petr Machata Acked-by: Roopa Prabhu Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

vxlan: fix tos value before xmit

2020-01-12T11:17:27+00:00

[ Upstream commit 71130f29979c7c7956b040673e6b9d5643003176 ] Before ip_tunnel_ecn_encap() and udp_tunnel_xmit_skb() we should filter tos value by RT_TOS() instead of using config tos directly. vxlan_get_route() would filter the tos to fl4.flowi4_tos but we didn't return it back, as geneve_get_v4_rt() did. So we have to use RT_TOS() directly in function ip_tunnel_ecn_encap(). Fixes: 206aaafcd279 ("VXLAN: Use IP Tunnels tunnel ENC encap API") Fixes: 1400615d64cf ("vxlan: allow setting ipv6 traffic class") Signed-off-by: Hangbin Liu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

vxlan: Fix error path in __vxlan_dev_create()

2019-12-05T08:20:38+00:00

[ Upstream commit 6db9246871394b3a136cd52001a0763676563840 ] When a failure occurs in rtnl_configure_link(), the current code calls unregister_netdevice() to roll back the earlier call to register_netdevice(), and jumps to errout, which calls vxlan_fdb_destroy(). However unregister_netdevice() calls transitively ndo_uninit, which is vxlan_uninit(), and that already takes care of deleting the default FDB entry by calling vxlan_fdb_delete_default(). Since the entry added earlier in __vxlan_dev_create() is exactly the default entry, the cleanup code in the errout block always leads to double free and thus a panic. Besides, since vxlan_fdb_delete_default() always destroys the FDB entry with notification enabled, the deletion of the default entry is notified even before the addition was notified. Instead, move the unregister_netdevice() call after the manual destroy, which solves both problems. Fixes: 0241b836732f ("vxlan: fix default fdb entry netlink notify ordering during netdev create") Signed-off-by: Petr Machata Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

vxlan: check tun_info options_len properly

2019-11-10T10:27:46+00:00

[ Upstream commit eadf52cf1852196a1363044dcda22fa5d7f296f7 ] This patch is to improve the tun_info options_len by dropping the skb when TUNNEL_VXLAN_OPT is set but options_len is less than vxlan_metadata. This can void a potential out-of-bounds access on ip_tun_info. Fixes: ee122c79d422 ("vxlan: Flow based tunneling") Signed-off-by: Xin Long Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

vxlan: Don't call gro_cells_destroy() before device is unregistered

2019-04-03T04:26:18+00:00

[ Upstream commit cc4807bb609230d8959fd732b0bf3bd4c2de8eac ] Commit ad6c9986bcb62 ("vxlan: Fix GRO cells race condition between receive and link delete") fixed a race condition for the typical case a vxlan device is dismantled from the current netns. But if a netns is dismantled, vxlan_destroy_tunnels() is called to schedule a unregister_netdevice_queue() of all the vxlan tunnels that are related to this netns. In vxlan_destroy_tunnels(), gro_cells_destroy() is called and finished before unregister_netdevice_queue(). This means that the gro_cells_destroy() call is done too soon, for the same reasons explained in above commit. So we need to fully respect the RCU rules, and thus must remove the gro_cells_destroy() call or risk use after-free. Fixes: 58ce31cca1ff ("vxlan: GRO support at tunnel layer") Signed-off-by: Suanming.Mou Suggested-by: Eric Dumazet Reviewed-by: Stefano Brivio Reviewed-by: Zhiqiang Liu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

vxlan: test dev->flags & IFF_UP before calling gro_cells_receive()

2019-03-19T12:12:40+00:00

[ Upstream commit 59cbf56fcd98ba2a715b6e97c4e43f773f956393 ] Same reasons than the ones explained in commit 4179cb5a4c92 ("vxlan: test dev->flags & IFF_UP before calling netif_rx()") netif_rx() or gro_cells_receive() must be called under a strict contract. At device dismantle phase, core networking clears IFF_UP and flush_all_backlogs() is called after rcu grace period to make sure no incoming packet might be in a cpu backlog and still referencing the device. A similar protocol is used for gro_cells infrastructure, as gro_cells_destroy() will be called only after a full rcu grace period is observed after IFF_UP has been cleared. Most drivers call netif_rx() from their interrupt handler, and since the interrupts are disabled at device dismantle, netif_rx() does not have to check dev->flags & IFF_UP Virtual drivers do not have this guarantee, and must therefore make the check themselves. Otherwise we risk use-after-free and/or crashes. Fixes: d342894c5d2f ("vxlan: virtual extensible lan") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

vxlan: Fix GRO cells race condition between receive and link delete

2019-03-19T12:12:39+00:00

[ Upstream commit ad6c9986bcb627c7c22b8f9e9a934becc27df87c ] If we receive a packet while deleting a VXLAN device, there's a chance vxlan_rcv() is called at the same time as vxlan_dellink(). This is fine, except that vxlan_dellink() should never ever touch stuff that's still in use, such as the GRO cells list. Otherwise, vxlan_rcv() crashes while queueing packets via gro_cells_receive(). Move the gro_cells_destroy() to vxlan_uninit(), which runs after the RCU grace period is elapsed and nothing needs the gro_cells anymore. This is now done in the same way as commit 8e816df87997 ("geneve: Use GRO cells infrastructure.") originally implemented for GENEVE. Reported-by: Jianlin Shi Fixes: 58ce31cca1ff ("vxlan: GRO support at tunnel layer") Signed-off-by: Stefano Brivio Reviewed-by: Sabrina Dubroca Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

vxlan: test dev->flags & IFF_UP before calling netif_rx()

2019-02-23T08:07:25+00:00

[ Upstream commit 4179cb5a4c924cd233eaadd081882425bc98f44e ] netif_rx() must be called under a strict contract. At device dismantle phase, core networking clears IFF_UP and flush_all_backlogs() is called after rcu grace period to make sure no incoming packet might be in a cpu backlog and still referencing the device. Most drivers call netif_rx() from their interrupt handler, and since the interrupts are disabled at device dismantle, netif_rx() does not have to check dev->flags & IFF_UP Virtual drivers do not have this guarantee, and must therefore make the check themselves. Otherwise we risk use-after-free and/or crashes. Note this patch also fixes a small issue that came with commit ce6502a8f957 ("vxlan: fix a use after free in vxlan_encap_bypass"), since the dev->stats.rx_dropped change was done on the wrong device. Fixes: d342894c5d2f ("vxlan: virtual extensible lan") Fixes: ce6502a8f957 ("vxlan: fix a use after free in vxlan_encap_bypass") Signed-off-by: Eric Dumazet Cc: Petr Machata Cc: Ido Schimmel Cc: Roopa Prabhu Cc: Stefano Brivio Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

geneve, vxlan: Don't set exceptions if skb->len < mtu

2018-10-18T04:51:13+00:00

We shouldn't abuse exceptions: if the destination MTU is already higher than what we're transmitting, no exception should be created. Fixes: 52a589d51f10 ("geneve: update skb dst pmtu on tx path") Fixes: a93bf0ff4490 ("vxlan: update skb dst pmtu on tx path") Signed-off-by: Stefano Brivio Reviewed-by: Sabrina Dubroca Signed-off-by: David S. Miller

geneve, vxlan: Don't check skb_dst() twice

2018-10-18T04:51:13+00:00

Commit f15ca723c1eb ("net: don't call update_pmtu unconditionally") avoids that we try updating PMTU for a non-existent destination, but didn't clean up cases where the check was already explicit. Drop those redundant checks. Signed-off-by: Stefano Brivio Reviewed-by: Sabrina Dubroca Signed-off-by: David S. Miller