kernel.git/net/openvswitch/actions.c, branch linux-5.11.y

openvswitch: fix stack OOB read while fragmenting IPv4 packets

2021-05-12T06:37:32Z

commit 7c0ea5930c1c211931819d83cfb157bff1539a4c upstream. running openvswitch on kernels built with KASAN, it's possible to see the following splat while testing fragmentation of IPv4 packets: BUG: KASAN: stack-out-of-bounds in ip_do_fragment+0x1b03/0x1f60 Read of size 1 at addr ffff888112fc713c by task handler2/1367 CPU: 0 PID: 1367 Comm: handler2 Not tainted 5.12.0-rc6+ #418 Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014 Call Trace: dump_stack+0x92/0xc1 print_address_description.constprop.7+0x1a/0x150 kasan_report.cold.13+0x7f/0x111 ip_do_fragment+0x1b03/0x1f60 ovs_fragment+0x5bf/0x840 [openvswitch] do_execute_actions+0x1bd5/0x2400 [openvswitch] ovs_execute_actions+0xc8/0x3d0 [openvswitch] ovs_packet_cmd_execute+0xa39/0x1150 [openvswitch] genl_family_rcv_msg_doit.isra.15+0x227/0x2d0 genl_rcv_msg+0x287/0x490 netlink_rcv_skb+0x120/0x380 genl_rcv+0x24/0x40 netlink_unicast+0x439/0x630 netlink_sendmsg+0x719/0xbf0 sock_sendmsg+0xe2/0x110 ____sys_sendmsg+0x5ba/0x890 ___sys_sendmsg+0xe9/0x160 __sys_sendmsg+0xd3/0x170 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f957079db07 Code: c3 66 90 41 54 41 89 d4 55 48 89 f5 53 89 fb 48 83 ec 10 e8 eb ec ff ff 44 89 e2 48 89 ee 89 df 41 89 c0 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 48 89 44 24 08 e8 24 ed ff ff 48 RSP: 002b:00007f956ce35a50 EFLAGS: 00000293 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000019 RCX: 00007f957079db07 RDX: 0000000000000000 RSI: 00007f956ce35ae0 RDI: 0000000000000019 RBP: 00007f956ce35ae0 R08: 0000000000000000 R09: 00007f9558006730 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007f956ce37308 R14: 00007f956ce35f80 R15: 00007f956ce35ae0 The buggy address belongs to the page: page:00000000af2a1d93 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x112fc7 flags: 0x17ffffc0000000() raw: 0017ffffc0000000 0000000000000000 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected addr ffff888112fc713c is located in stack of task handler2/1367 at offset 180 in frame: ovs_fragment+0x0/0x840 [openvswitch] this frame has 2 objects: [32, 144) 'ovs_dst' [192, 424) 'ovs_rt' Memory state around the buggy address: ffff888112fc7000: f3 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888112fc7080: 00 f1 f1 f1 f1 00 00 00 00 00 00 00 00 00 00 00 >ffff888112fc7100: 00 00 00 f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 00 ^ ffff888112fc7180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888112fc7200: 00 00 00 00 00 00 f2 f2 f2 00 00 00 00 00 00 00 for IPv4 packets, ovs_fragment() uses a temporary struct dst_entry. Then, in the following call graph: ip_do_fragment() ip_skb_dst_mtu() ip_dst_mtu_maybe_forward() ip_mtu_locked() the pointer to struct dst_entry is used as pointer to struct rtable: this turns the access to struct members like rt_mtu_locked into an OOB read in the stack. Fix this changing the temporary variable used for IPv4 packets in ovs_fragment(), similarly to what is done for IPv6 few lines below. Fixes: d52e5a7e7ca4 ("ipv4: lock mtu in fnhe when received PMTU < net.ipv4.route.min_pmt") Cc: Acked-by: Eelco Chaudron Signed-off-by: Davide Caratti Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: openvswitch: fix TTL decrement exception action execution

2020-12-15T01:18:25Z

Currently, the exception actions are not processed correctly as the wrong dataset is passed. This change fixes this, including the misleading comment. In addition, a check was added to make sure we work on an IPv4 packet, and not just assume if it's not IPv6 it's IPv4. This was all tested using OVS with patch, https://patchwork.ozlabs.org/project/openvswitch/list/?series=21639, applied and sending packets with a TTL of 1 (and 0), both with IPv4 and IPv6. Fixes: 69929d4c49e1 ("net: openvswitch: fix TTL decrement action netlink message format") Signed-off-by: Eelco Chaudron Link: https://lore.kernel.org/r/160733569860.3007.12938188180387116741.stgit@wsfd-netdev64.ntdv.lab.eng.bos.redhat.com Signed-off-by: Jakub Kicinski

net: openvswitch: ensure LSE is pullable before reading it

2020-12-03T19:13:29Z

when openvswitch is configured to mangle the LSE, the current value is read from the packet dereferencing 4 bytes at mpls_hdr(): ensure that the label is contained in the skb "linear" area. Found by code inspection. Fixes: d27cf5c59a12 ("net: core: add MPLS update core helper and use in OvS") Signed-off-by: Davide Caratti Link: https://lore.kernel.org/r/aa099f245d93218b84b5c056b67b6058ccf81a66.1606987185.git.dcaratti@redhat.com Signed-off-by: Jakub Kicinski

net: openvswitch: fix TTL decrement action netlink message format

2020-11-27T19:03:06Z

Currently, the openvswitch module is not accepting the correctly formated netlink message for the TTL decrement action. For both setting and getting the dec_ttl action, the actions should be nested in the OVS_DEC_TTL_ATTR_ACTION attribute as mentioned in the openvswitch.h uapi. When the original patch was sent, it was tested with a private OVS userspace implementation. This implementation was unfortunately not upstreamed and reviewed, hence an erroneous version of this patch was sent out. Leaving the patch as-is would cause problems as the kernel module could interpret additional attributes as actions and vice-versa, due to the actions not being encapsulated/nested within the actual attribute, but being concatinated after it. Fixes: 744676e77720 ("openvswitch: add TTL decrement action") Signed-off-by: Eelco Chaudron Link: https://lore.kernel.org/r/160622121495.27296.888010441924340582.stgit@wsfd-netdev64.ntdv.lab.eng.bos.redhat.com Signed-off-by: Jakub Kicinski

net/sched: act_vlan: Add {POP,PUSH}_ETH actions

2020-10-04T00:28:45Z

Implement TCA_VLAN_ACT_POP_ETH and TCA_VLAN_ACT_PUSH_ETH, to respectively pop and push a base Ethernet header at the beginning of a frame. POP_ETH is just a matter of pulling ETH_HLEN bytes. VLAN tags, if any, must be stripped before calling POP_ETH. PUSH_ETH is restricted to skbs with no mac_header, and only the MAC addresses can be configured. The Ethertype is automatically set from skb->protocol. These restrictions ensure that all skb's fields remain consistent, so that this action can't confuse other part of the networking stack (like GSO). Since openvswitch already had these actions, consolidate the code in skbuff.c (like for vlan and mpls push/pop). Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller

net: openvswitch: improve the coding style

2020-09-01T18:42:15Z

Not change the logic, just improve the coding style. Cc: Pravin B Shelar Signed-off-by: Tonghao Zhang Acked-by: Pravin B Shelar Signed-off-by: David S. Miller

openvswitch: using ip6_fragment in ipv6_stub

2020-08-31T19:26:39Z

Using ipv6_stub->ipv6_fragment to avoid the netfilter dependency Signed-off-by: wenxu Signed-off-by: David S. Miller

openvswitch: take into account de-fragmentation/gso_size in execute_check_pkt_len

2020-06-24T21:34:58Z

ovs connection tracking module performs de-fragmentation on incoming fragmented traffic. Take info account if traffic has been de-fragmented in execute_check_pkt_len action otherwise we will perform the wrong nested action considering the original packet size. This issue typically occurs if ovs-vswitchd adds a rule in the pipeline that requires connection tracking (e.g. OVN stateful ACLs) before execute_check_pkt_len action. Moreover take into account GSO fragment size for GSO packet in execute_check_pkt_len routine Fixes: 4d5ec89fc8d14 ("net: openvswitch: Add a new action check_pkt_len") Signed-off-by: Lorenzo Bianconi Signed-off-by: David S. Miller

openvswitch: add TTL decrement action

2020-02-17T03:34:44Z

New action to decrement TTL instead of setting it to a fixed value. This action will decrement the TTL and, in case of expired TTL, drop it or execute an action passed via a nested attribute. The default TTL expired action is to drop the packet. Supports both IPv4 and IPv6 via the ttl and hop_limit fields, respectively. Tested with a corresponding change in the userspace: # ovs-dpctl dump-flows in_port(2),eth(),eth_type(0x0800), packets:0, bytes:0, used:never, actions:dec_ttl{ttl<=1 action:(drop)},1 in_port(1),eth(),eth_type(0x0800), packets:0, bytes:0, used:never, actions:dec_ttl{ttl<=1 action:(drop)},2 in_port(1),eth(),eth_type(0x0806), packets:0, bytes:0, used:never, actions:2 in_port(2),eth(),eth_type(0x0806), packets:0, bytes:0, used:never, actions:1 # ping -c1 192.168.0.2 -t 42 IP (tos 0x0, ttl 41, id 61647, offset 0, flags [DF], proto ICMP (1), length 84) 192.168.0.1 > 192.168.0.2: ICMP echo request, id 386, seq 1, length 64 # ping -c1 192.168.0.2 -t 120 IP (tos 0x0, ttl 119, id 62070, offset 0, flags [DF], proto ICMP (1), length 84) 192.168.0.1 > 192.168.0.2: ICMP echo request, id 388, seq 1, length 64 # ping -c1 192.168.0.2 -t 1 # Co-developed-by: Bindiya Kurle Signed-off-by: Bindiya Kurle Signed-off-by: Matteo Croce Acked-by: Pravin B Shelar Signed-off-by: David S. Miller

openvswitch: New MPLS actions for layer 2 tunnelling

2019-12-25T06:24:45Z

The existing PUSH MPLS action inserts MPLS header between ethernet header and the IP header. Though this behaviour is fine for L3 VPN where an IP packet is encapsulated inside a MPLS tunnel, it does not suffice the L2 VPN (l2 tunnelling) requirements. In L2 VPN the MPLS header should encapsulate the ethernet packet. The new mpls action ADD_MPLS inserts MPLS header at the start of the packet or at the start of the l3 header depending on the value of l3 tunnel flag in the ADD_MPLS arguments. POP_MPLS action is extended to support ethertype 0x6558. Signed-off-by: Martin Varghese Acked-by: Pravin B Shelar Signed-off-by: David S. Miller