linux-stable.git/net/openvswitch/datapath.c, branch linux-4.9.y

openvswitch: Fix flow lookup to use unmasked key

2023-01-07T11:07:29+00:00

[ Upstream commit 68bb10101e6b0a6bb44e9c908ef795fc4af99eae ]

The commit mentioned below causes the ovs_flow_tbl_lookup() function
to be called with the masked key. However, it's supposed to be called
with the unmasked key. This due to the fact that the datapath supports
installing wider flows, and OVS relies on this behavior. For example
if ipv4(src=1.1.1.1/192.0.0.0, dst=1.1.1.2/192.0.0.0) exists, a wider
flow (smaller mask) of ipv4(src=192.1.1.1/128.0.0.0,dst=192.1.1.2/
128.0.0.0) is allowed to be added.

However, if we try to add a wildcard rule, the installation fails:

$ ovs-appctl dpctl/add-flow system@myDP "in_port(1),eth_type(0x0800), \
  ipv4(src=1.1.1.1/192.0.0.0,dst=1.1.1.2/192.0.0.0,frag=no)" 2
$ ovs-appctl dpctl/add-flow system@myDP "in_port(1),eth_type(0x0800), \
  ipv4(src=192.1.1.1/0.0.0.0,dst=49.1.1.2/0.0.0.0,frag=no)" 2
ovs-vswitchd: updating flow table (File exists)

The reason is that the key used to determine if the flow is already
present in the system uses the original key ANDed with the mask.
This results in the IP address not being part of the (miniflow) key,
i.e., being substituted with an all-zero value. When doing the actual
lookup, this results in the key wrongfully matching the first flow,
and therefore the flow does not get installed.

This change reverses the commit below, but rather than having the key
on the stack, it's allocated.

Fixes: 190aa3e77880 ("openvswitch: Fix Frame-size larger than 1024 bytes warning.")

Signed-off-by: Eelco Chaudron 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

openvswitch: switch from WARN to pr_warn

2022-11-03T14:49:19+00:00

[ Upstream commit fd954cc1919e35cb92f78671cab6e42d661945a3 ]

As noted by Paolo Abeni, pr_warn doesn't generate any splat and can still
preserve the warning to the user that feature downgrade occurred.  We
likely cannot introduce other kinds of checks / enforcement here because
syzbot can generate different genl versions to the datapath.

Reported-by: syzbot+31cde0bef4bbf8ba2d86@syzkaller.appspotmail.com
Fixes: 44da5ae5fbea ("openvswitch: Drop user features if old user space attempted to create datapath")
Cc: Thomas Graf 
Signed-off-by: Aaron Conole 
Acked-by: Ilya Maximets 
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

openvswitch: Fix overreporting of drops in dropwatch

2022-10-26T11:15:45+00:00

[ Upstream commit c21ab2afa2c64896a7f0e3cbc6845ec63dcfad2e ]

Currently queue_userspace_packet will call kfree_skb for all frames,
whether or not an error occurred. This can result in a single dropped
frame being reported as multiple drops in dropwatch. This functions
caller may also call kfree_skb in case of an error. This patch will
consume the skbs instead and allow caller's to use kfree_skb.

Signed-off-by: Mike Pattrick 
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2109957
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

openvswitch: Fix double reporting of drops in dropwatch

2022-10-26T11:15:45+00:00

[ Upstream commit 1100248a5c5ccd57059eb8d02ec077e839a23826 ]

Frames sent to userspace can be reported as dropped in
ovs_dp_process_packet, however, if they are dropped in the netlink code
then netlink_attachskb will report the same frame as dropped.

This patch checks for error codes which indicate that the frame has
already been freed.

Signed-off-by: Mike Pattrick 
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2109946
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

openvswitch: remove another BUG_ON()

2019-12-05T14:35:28+00:00

[ Upstream commit 8a574f86652a4540a2433946ba826ccb87f398cc ]

If we can't build the flow del notification, we can simply delete
the flow, no need to crash the kernel. Still keep a WARN_ON to
preserve debuggability.

Note: the BUG_ON() predates the Fixes tag, but this change
can be applied only after the mentioned commit.

v1 -> v2:
 - do not leak an skb on error

Fixes: aed067783e50 ("openvswitch: Minimize ovs_flow_cmd_del critical section.")
Signed-off-by: Paolo Abeni 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

openvswitch: drop unneeded BUG_ON() in ovs_flow_cmd_build_info()

2019-12-05T14:35:27+00:00

[ Upstream commit 8ffeb03fbba3b599690b361467bfd2373e8c450f ]

All the callers of ovs_flow_cmd_build_info() already deal with
error return code correctly, so we can handle the error condition
in a more gracefull way. Still dump a warning to preserve
debuggability.

v1 -> v2:
 - clarify the commit message
 - clean the skb and report the error (DaveM)

Fixes: ccb1352e76cf ("net: Add Open vSwitch kernel components.")
Signed-off-by: Paolo Abeni 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

openvswitch: fix flow command message size

2019-12-05T14:35:26+00:00

[ Upstream commit 4e81c0b3fa93d07653e2415fa71656b080a112fd ]

When user-space sets the OVS_UFID_F_OMIT_* flags, and the relevant
flow has no UFID, we can exceed the computed size, as
ovs_nla_put_identifier() will always dump an OVS_FLOW_ATTR_KEY
attribute.
Take the above in account when computing the flow command message
size.

Fixes: 74ed7ab9264c ("openvswitch: Add support for unique flow IDs.")
Reported-by: Qi Jun Ding 
Signed-off-by: Paolo Abeni 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

openvswitch: change type of UPCALL_PID attribute to NLA_UNSPEC

2019-10-05T10:30:13+00:00

[ Upstream commit ea8564c865299815095bebeb4b25bef474218e4c ]

userspace openvswitch patch "(dpif-linux: Implement the API
functions to allow multiple handler threads read upcall)"
changes its type from U32 to UNSPEC, but leave the kernel
unchanged

and after kernel 6e237d099fac "(netlink: Relax attr validation
for fixed length types)", this bug is exposed by the below
warning

	[   57.215841] netlink: 'ovs-vswitchd': attribute type 5 has an invalid length.

Fixes: 5cd667b0a456 ("openvswitch: Allow each vport to have an array of 'port_id's")
Signed-off-by: Li RongQing 
Acked-by: Pravin B Shelar 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

openvswitch: fix skb_panic due to the incorrect actions attrlen

2017-08-30T08:21:40+00:00

[ Upstream commit 494bea39f3201776cdfddc232705f54a0bd210c4 ]

For sw_flow_actions, the actions_len only represents the kernel part's
size, and when we dump the actions to the userspace, we will do the
convertions, so it's true size may become bigger than the actions_len.

But unfortunately, for OVS_PACKET_ATTR_ACTIONS, we use the actions_len
to alloc the skbuff, so the user_skb's size may become insufficient and
oops will happen like this:
  skbuff: skb_over_panic: text:ffffffff8148fabf len:1749 put:157 head:
  ffff881300f39000 data:ffff881300f39000 tail:0x6d5 end:0x6c0 dev:
  ------------[ cut here ]------------
  kernel BUG at net/core/skbuff.c:129!
  [...]
  Call Trace:
   
   [] skb_put+0x43/0x44
   [] skb_zerocopy+0x6c/0x1f4
   [] queue_userspace_packet+0x3a3/0x448 [openvswitch]
   [] ovs_dp_upcall+0x30/0x5c [openvswitch]
   [] output_userspace+0x132/0x158 [openvswitch]
   [] ? ip6_rcv_finish+0x74/0x77 [ipv6]
   [] do_execute_actions+0xcc1/0xdc8 [openvswitch]
   [] ovs_execute_actions+0x74/0x106 [openvswitch]
   [] ovs_dp_process_packet+0xe1/0xfd [openvswitch]
   [] ? key_extract+0x63c/0x8d5 [openvswitch]
   [] ovs_vport_receive+0xa1/0xc3 [openvswitch]
  [...]

Also we can find that the actions_len is much little than the orig_len:
  crash> struct sw_flow_actions 0xffff8812f539d000
  struct sw_flow_actions {
    rcu = {
      next = 0xffff8812f5398800,
      func = 0xffffe3b00035db32
    },
    orig_len = 1384,
    actions_len = 592,
    actions = 0xffff8812f539d01c
  }

So as a quick fix, use the orig_len instead of the actions_len to alloc
the user_skb.

Last, this oops happened on our system running a relative old kernel, but
the same risk still exists on the mainline, since we use the wrong
actions_len from the beginning.

Fixes: ccea74457bbd ("openvswitch: include datapath actions with sampled-packet upcall to userspace")
Cc: Neil McKee 
Signed-off-by: Liping Zhang 
Acked-by: Pravin B Shelar 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

openvswitch: avoid resetting flow key while installing new flow.

2016-09-21T02:54:35+00:00

since commit commit db74a3335e0f6 ("openvswitch: use percpu
flow stats") flow alloc resets flow-key. So there is no need
to reset the flow-key again if OVS is using newly allocated
flow-key.

Signed-off-by: Pravin B Shelar 
Signed-off-by: David S. Miller