[ovs-git] [openvswitch/ovs] ed16fb: ofp-ed-props: Fix using uninitialized padding for ...

Ilya Maximets noreply at github.com
Mon Oct 19 12:55:48 UTC 2020


  Branch: refs/heads/branch-2.12
  Home:   https://github.com/openvswitch/ovs
  Commit: ed16fb1be072dc2e12193ac236ff5bd5020012b2
      https://github.com/openvswitch/ovs/commit/ed16fb1be072dc2e12193ac236ff5bd5020012b2
  Author: Ilya Maximets <i.maximets at ovn.org>
  Date:   2020-10-15 (Thu, 15 Oct 2020)

  Changed paths:
    M lib/ofp-ed-props.c
    M tests/ofp-actions.at

  Log Message:
  -----------
  ofp-ed-props: Fix using uninitialized padding for NSH encap actions.

OVS uses memcmp to compare actions of existing and new flows, but
'struct ofp_ed_prop_nsh_md_type' and corresponding ofpact structure has
3 bytes of padding that never initialized and passed around within OF
data structures and messages.

  Uninitialized bytes in MemcmpInterceptorCommon
    at offset 21 inside [0x7090000003f8, 136)
  WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x4a184e in bcmp (vswitchd/ovs-vswitchd+0x4a184e)
    #1 0x896c8a in ofpacts_equal lib/ofp-actions.c:9121:31
    #2 0x564403 in replace_rule_finish ofproto/ofproto.c:5650:37
    #3 0x563462 in add_flow_finish ofproto/ofproto.c:5218:13
    #4 0x54a1ff in ofproto_flow_mod_finish ofproto/ofproto.c:8091:17
    #5 0x5433b2 in handle_flow_mod__ ofproto/ofproto.c:6216:17
    #6 0x56a2fc in handle_flow_mod ofproto/ofproto.c:6190:17
    #7 0x565bda in handle_single_part_openflow ofproto/ofproto.c:8504:16
    #8 0x540b25 in handle_openflow ofproto/ofproto.c:8685:21
    #9 0x6697fd in ofconn_run ofproto/connmgr.c:1329:13
    #10 0x668e6e in connmgr_run ofproto/connmgr.c:356:9
    #11 0x53f1bc in ofproto_run ofproto/ofproto.c:1890:5
    #12 0x4ead0c in bridge_run__ vswitchd/bridge.c:3250:9
    #13 0x4e9bc8 in bridge_run vswitchd/bridge.c:3309:5
    #14 0x51c072 in main vswitchd/ovs-vswitchd.c:127:9
    #15 0x7f23a99011a2 in __libc_start_main (/lib64/libc.so.6)
    #16 0x46b92d in _start (vswitchd/ovs-vswitchd+0x46b92d)

  Uninitialized value was stored to memory at
    #0 0x4745aa in __msan_memcpy.part.0 (vswitchd/ovs-vswitchd)
    #1 0x54529f in rule_actions_create ofproto/ofproto.c:3134:5
    #2 0x54915e in ofproto_rule_create ofproto/ofproto.c:5284:11
    #3 0x55d419 in add_flow_init ofproto/ofproto.c:5123:17
    #4 0x54841f in ofproto_flow_mod_init ofproto/ofproto.c:7987:17
    #5 0x543250 in handle_flow_mod__ ofproto/ofproto.c:6206:13
    #6 0x56a2fc in handle_flow_mod ofproto/ofproto.c:6190:17
    #7 0x565bda in handle_single_part_openflow ofproto/ofproto.c:8504:16
    #8 0x540b25 in handle_openflow ofproto/ofproto.c:8685:21
    #9 0x6697fd in ofconn_run ofproto/connmgr.c:1329:13
    #10 0x668e6e in connmgr_run ofproto/connmgr.c:356:9
    #11 0x53f1bc in ofproto_run ofproto/ofproto.c:1890:5
    #12 0x4ead0c in bridge_run__ vswitchd/bridge.c:3250:9
    #13 0x4e9bc8 in bridge_run vswitchd/bridge.c:3309:5
    #14 0x51c072 in main vswitchd/ovs-vswitchd.c:127:9
    #15 0x7f23a99011a2 in __libc_start_main (/lib64/libc.so.6)

  Uninitialized value was created by an allocation of 'ofpacts_stub'
  in the stack frame of function 'handle_flow_mod'
    #0 0x569e80 in handle_flow_mod ofproto/ofproto.c:6170

This could cause issues with flow modifications or other operations.

To reproduce, some NSH tests could be run under valgrind or clang
MemorySantizer. Ex. "nsh - md1 encap over a veth link" test.

Fix that by clearing padding bytes while encoding and decoding.
OVS will still accept OF messages with non-zero padding from
controllers.

New tests added to tests/ofp-actions.at.

Fixes: 1fc11c5948cf ("Generic encap and decap support for NSH")
Signed-off-by: Ilya Maximets <i.maximets at ovn.org>
Acked-by: Jan Scheurich <jan.scheurich at ericsson.com>




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