Re: [ovs-dev] [PATCH v2] ofp-ed-props: Fix using uninitialized padding for NSH encap actions.
On 10/14/20 10:58 PM, Jan Scheurich wrote:
> LGTM. Please back-port to stable branches.
>
> Acked-by: Jan Scheurich
Thanks!
Applied to master and backported down to 2.8.
Best regards, Ilya Maximets.
>
> /Jan
>
>> -Original Message-
>> From: Ilya Maximets
>> Sent: Wednesday, 14 October, 2020 18:14
>> To: ovs-dev@openvswitch.org; Jan Scheurich
>> Cc: Ben Pfaff ; Ilya Maximets
>> Subject: [PATCH v2] 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 [0x709003f8, 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
>> ---
>> lib/ofp-ed-props.c | 3 ++-
>> tests/ofp-actions.at | 11 +++
>> 2 files changed, 13 insertions(+), 1 deletion(-)
>>
>> diff --git a/lib/ofp-ed-props.c b/lib/ofp-ed-props.c index
>> 28382e012..02a9235d5 100644
>> --- a/lib/ofp-ed-props.c
>> +++ b/lib/ofp-ed-props.c
>> @@ -49,7 +49,7 @@ decode_ed_prop(const struct ofp_ed_prop_header
>> **ofp_prop,
>> return OFPERR_NXBAC_BAD_ED_PROP;
>> }
>> struct ofpact_ed_prop_nsh_md_type *pnmt =
>> -ofpbuf_put_uninit(out, sizeof(*pnmt));
>> +ofpbuf_put_zeros(out, sizeof *pnmt);
>> pnmt->header.prop_class = prop_class;
>> pnmt->header.type = prop_type;
>> pnmt->header.len = len;
>> @@ -108,6 +108,7 @@ encode_ed_prop(const struct ofpact_ed_prop
>> **prop,
>> opnmt->header.len =
>> offsetof(struct ofp_ed_prop_nsh_md_type, pad);
>> opnmt->md_type = pnmt->md_type;
>> +memset(opnmt->pad, 0, sizeof opnmt->pad);
>> prop_len = sizeof(*pnmt);
>> break;
>> }
>> diff --git a/tests/ofp-actions.at b/tests/ofp-actions.at index
>> 28b2099a0..c79d7d0e2 100644
>>
Re: [ovs-dev] [PATCH v2] ofp-ed-props: Fix using uninitialized padding for NSH encap actions.
LGTM. Please back-port to stable branches.
Acked-by: Jan Scheurich
/Jan
> -Original Message-
> From: Ilya Maximets
> Sent: Wednesday, 14 October, 2020 18:14
> To: ovs-dev@openvswitch.org; Jan Scheurich
> Cc: Ben Pfaff ; Ilya Maximets
> Subject: [PATCH v2] 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 [0x709003f8, 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
> ---
> lib/ofp-ed-props.c | 3 ++-
> tests/ofp-actions.at | 11 +++
> 2 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/lib/ofp-ed-props.c b/lib/ofp-ed-props.c index
> 28382e012..02a9235d5 100644
> --- a/lib/ofp-ed-props.c
> +++ b/lib/ofp-ed-props.c
> @@ -49,7 +49,7 @@ decode_ed_prop(const struct ofp_ed_prop_header
> **ofp_prop,
> return OFPERR_NXBAC_BAD_ED_PROP;
> }
> struct ofpact_ed_prop_nsh_md_type *pnmt =
> -ofpbuf_put_uninit(out, sizeof(*pnmt));
> +ofpbuf_put_zeros(out, sizeof *pnmt);
> pnmt->header.prop_class = prop_class;
> pnmt->header.type = prop_type;
> pnmt->header.len = len;
> @@ -108,6 +108,7 @@ encode_ed_prop(const struct ofpact_ed_prop
> **prop,
> opnmt->header.len =
> offsetof(struct ofp_ed_prop_nsh_md_type, pad);
> opnmt->md_type = pnmt->md_type;
> +memset(opnmt->pad, 0, sizeof opnmt->pad);
> prop_len = sizeof(*pnmt);
> break;
> }
> diff --git a/tests/ofp-actions.at b/tests/ofp-actions.at index
> 28b2099a0..c79d7d0e2 100644
> --- a/tests/ofp-actions.at
> +++ b/tests/ofp-actions.at
> @@ -769,6 +769,17 @@ dnl Check OpenFlow v1.3.4 Conformance Test:
> 430.510.
> & 0010 00 00 00 10 00 00 00 01-
> 0019 0010 8807 000102030405 0010 0001
>
[ovs-dev] [PATCH v2] 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 [0x709003f8, 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
---
lib/ofp-ed-props.c | 3 ++-
tests/ofp-actions.at | 11 +++
2 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/lib/ofp-ed-props.c b/lib/ofp-ed-props.c
index 28382e012..02a9235d5 100644
--- a/lib/ofp-ed-props.c
+++ b/lib/ofp-ed-props.c
@@ -49,7 +49,7 @@ decode_ed_prop(const struct ofp_ed_prop_header **ofp_prop,
return OFPERR_NXBAC_BAD_ED_PROP;
}
struct ofpact_ed_prop_nsh_md_type *pnmt =
-ofpbuf_put_uninit(out, sizeof(*pnmt));
+ofpbuf_put_zeros(out, sizeof *pnmt);
pnmt->header.prop_class = prop_class;
pnmt->header.type = prop_type;
pnmt->header.len = len;
@@ -108,6 +108,7 @@ encode_ed_prop(const struct ofpact_ed_prop **prop,
opnmt->header.len =
offsetof(struct ofp_ed_prop_nsh_md_type, pad);
opnmt->md_type = pnmt->md_type;
+memset(opnmt->pad, 0, sizeof opnmt->pad);
prop_len = sizeof(*pnmt);
break;
}
diff --git a/tests/ofp-actions.at b/tests/ofp-actions.at
index 28b2099a0..c79d7d0e2 100644
--- a/tests/ofp-actions.at
+++ b/tests/ofp-actions.at
@@ -769,6 +769,17 @@ dnl Check OpenFlow v1.3.4 Conformance Test: 430.510.
& 0010 00 00 00 10 00 00 00 01-
0019 0010 8807 000102030405 0010 0001
+dnl Check NSH encap (experimenter extension).
+# actions=encap(nsh(md_type=1))
+ 0018 2320 002e 0001894f 0004 01 05 01 00
+
+dnl NSH encap with non-zero padding.
+# actions=encap(nsh(md_type=1))
+# 21: 12 -> 00
+# 22: 34 -> 00
+# 23: 56 -> 00
+ 0018 2320 002e 0001894f 0004 01 05 01 123456
+
])
sed '/^[[#&]]/d' < test-data > input.txt
sed -n 's/^# //p; /^$/p' < test-data > expout
--
2.25.4
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