* [PATCH] openvswitch: fix CVE-2021-36980
@ 2021-09-10 3:21 Zhang, Qiang
2021-09-16 22:07 ` Bruce Ashfield
0 siblings, 1 reply; 2+ messages in thread
From: Zhang, Qiang @ 2021-09-10 3:21 UTC (permalink / raw)
To: bruce.ashfield; +Cc: meta-virtualization
From: Zqiang <qiang.zhang@windriver.com>
Open vSwitch (aka openvswitch) 2.11.0 through 2.15.0 has
a use-after-free in decode_NXAST_RAW_ENCAP (called from
ofpact_decode and ofpacts_decode) during the decoding of
a RAW_ENCAP action.
Reference:
https://nvd.nist.gov/vuln/detail/CVE-2021-36980
Patches from:
https://github.com/openvswitch/ovs/commit/65c61b0c23a0d474696d7b1cea522a5016a8aeb3
Signed-off-by: Zqiang <qiang.zhang@windriver.com>
---
...use-after-free-while-decoding-RAW_EN.patch | 97 +++++++++++++++++++
.../openvswitch/openvswitch_git.bb | 1 +
2 files changed, 98 insertions(+)
create mode 100644 recipes-networking/openvswitch/files/0001-ofp-actions-Fix-use-after-free-while-decoding-RAW_EN.patch
diff --git a/recipes-networking/openvswitch/files/0001-ofp-actions-Fix-use-after-free-while-decoding-RAW_EN.patch b/recipes-networking/openvswitch/files/0001-ofp-actions-Fix-use-after-free-while-decoding-RAW_EN.patch
new file mode 100644
index 00000000..3afd1bad
--- /dev/null
+++ b/recipes-networking/openvswitch/files/0001-ofp-actions-Fix-use-after-free-while-decoding-RAW_EN.patch
@@ -0,0 +1,97 @@
+From 77cccc74deede443e8b9102299efc869a52b65b2 Mon Sep 17 00:00:00 2001
+From: Ilya Maximets <i.maximets@ovn.org>
+Date: Tue, 16 Feb 2021 23:27:30 +0100
+Subject: [PATCH] ofp-actions: Fix use-after-free while decoding RAW_ENCAP.
+
+While decoding RAW_ENCAP action, decode_ed_prop() might re-allocate
+ofpbuf if there is no enough space left. However, function
+'decode_NXAST_RAW_ENCAP' continues to use old pointer to 'encap'
+structure leading to write-after-free and incorrect decoding.
+
+ ==3549105==ERROR: AddressSanitizer: heap-use-after-free on address
+ 0x60600000011a at pc 0x0000005f6cc6 bp 0x7ffc3a2d4410 sp 0x7ffc3a2d4408
+ WRITE of size 2 at 0x60600000011a thread T0
+ #0 0x5f6cc5 in decode_NXAST_RAW_ENCAP lib/ofp-actions.c:4461:20
+ #1 0x5f0551 in ofpact_decode ./lib/ofp-actions.inc2:4777:16
+ #2 0x5ed17c in ofpacts_decode lib/ofp-actions.c:7752:21
+ #3 0x5eba9a in ofpacts_pull_openflow_actions__ lib/ofp-actions.c:7791:13
+ #4 0x5eb9fc in ofpacts_pull_openflow_actions lib/ofp-actions.c:7835:12
+ #5 0x64bb8b in ofputil_decode_packet_out lib/ofp-packet.c:1113:17
+ #6 0x65b6f4 in ofp_print_packet_out lib/ofp-print.c:148:13
+ #7 0x659e3f in ofp_to_string__ lib/ofp-print.c:1029:16
+ #8 0x659b24 in ofp_to_string lib/ofp-print.c:1244:21
+ #9 0x65a28c in ofp_print lib/ofp-print.c:1288:28
+ #10 0x540d11 in ofctl_ofp_parse utilities/ovs-ofctl.c:2814:9
+ #11 0x564228 in ovs_cmdl_run_command__ lib/command-line.c:247:17
+ #12 0x56408a in ovs_cmdl_run_command lib/command-line.c:278:5
+ #13 0x5391ae in main utilities/ovs-ofctl.c:179:9
+ #14 0x7f6911ce9081 in __libc_start_main (/lib64/libc.so.6+0x27081)
+ #15 0x461fed in _start (utilities/ovs-ofctl+0x461fed)
+
+Fix that by getting a new pointer before using.
+
+Credit to OSS-Fuzz.
+
+Fuzzer regression test will fail only with AddressSanitizer enabled.
+
+Reported-at: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=27851
+Fixes: f839892a206a ("OF support and translation of generic encap and decap")
+Acked-by: William Tu <u9012063@gmail.com>
+Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
+---
+ lib/ofp-actions.c | 2 ++
+ tests/automake.mk | 3 ++-
+ tests/fuzz-regression-list.at | 1 +
+ tests/fuzz-regression/ofp_print_fuzzer-6540965472632832 | 0
+ 4 files changed, 5 insertions(+), 1 deletion(-)
+ create mode 100644 tests/fuzz-regression/ofp_print_fuzzer-6540965472632832
+
+diff --git a/lib/ofp-actions.c b/lib/ofp-actions.c
+index e2e829772..0342a228b 100644
+--- a/lib/ofp-actions.c
++++ b/lib/ofp-actions.c
+@@ -4431,6 +4431,7 @@ decode_NXAST_RAW_ENCAP(const struct nx_action_encap *nae,
+ {
+ struct ofpact_encap *encap;
+ const struct ofp_ed_prop_header *ofp_prop;
++ const size_t encap_ofs = out->size;
+ size_t props_len;
+ uint16_t n_props = 0;
+ int err;
+@@ -4458,6 +4459,7 @@ decode_NXAST_RAW_ENCAP(const struct nx_action_encap *nae,
+ }
+ n_props++;
+ }
++ encap = ofpbuf_at_assert(out, encap_ofs, sizeof *encap);
+ encap->n_props = n_props;
+ out->header = &encap->ofpact;
+ ofpact_finish_ENCAP(out, &encap);
+diff --git a/tests/automake.mk b/tests/automake.mk
+index 677b99a6b..fc80e027d 100644
+--- a/tests/automake.mk
++++ b/tests/automake.mk
+@@ -134,7 +134,8 @@ FUZZ_REGRESSION_TESTS = \
+ tests/fuzz-regression/ofp_print_fuzzer-5722747668791296 \
+ tests/fuzz-regression/ofp_print_fuzzer-6285128790704128 \
+ tests/fuzz-regression/ofp_print_fuzzer-6470117922701312 \
+- tests/fuzz-regression/ofp_print_fuzzer-6502620041576448
++ tests/fuzz-regression/ofp_print_fuzzer-6502620041576448 \
++ tests/fuzz-regression/ofp_print_fuzzer-6540965472632832
+ $(srcdir)/tests/fuzz-regression-list.at: tests/automake.mk
+ $(AM_V_GEN)for name in $(FUZZ_REGRESSION_TESTS); do \
+ basename=`echo $$name | sed 's,^.*/,,'`; \
+diff --git a/tests/fuzz-regression-list.at b/tests/fuzz-regression-list.at
+index e3173fb88..2347c690e 100644
+--- a/tests/fuzz-regression-list.at
++++ b/tests/fuzz-regression-list.at
+@@ -21,3 +21,4 @@ TEST_FUZZ_REGRESSION([ofp_print_fuzzer-5722747668791296])
+ TEST_FUZZ_REGRESSION([ofp_print_fuzzer-6285128790704128])
+ TEST_FUZZ_REGRESSION([ofp_print_fuzzer-6470117922701312])
+ TEST_FUZZ_REGRESSION([ofp_print_fuzzer-6502620041576448])
++TEST_FUZZ_REGRESSION([ofp_print_fuzzer-6540965472632832])
+diff --git a/tests/fuzz-regression/ofp_print_fuzzer-6540965472632832 b/tests/fuzz-regression/ofp_print_fuzzer-6540965472632832
+new file mode 100644
+index 000000000..e69de29bb
+--
+2.17.1
+
diff --git a/recipes-networking/openvswitch/openvswitch_git.bb b/recipes-networking/openvswitch/openvswitch_git.bb
index 1fa7fb2c..4f5454fe 100644
--- a/recipes-networking/openvswitch/openvswitch_git.bb
+++ b/recipes-networking/openvswitch/openvswitch_git.bb
@@ -30,6 +30,7 @@ SRC_URI += "git://github.com/openvswitch/ovs.git;protocol=git;branch=branch-2.15
file://0001-ovs-use-run-instead-of-var-run-for-in-systemd-units.patch \
file://0001-openvswitch-fix-do_configure-with-DPDK-19.11-error.patch \
file://0001-openvswitch-fix-netdev-dpdk-compile-error.patch \
+ file://0001-ofp-actions-Fix-use-after-free-while-decoding-RAW_EN.patch \
"
LIC_FILES_CHKSUM = "file://LICENSE;md5=1ce5d23a6429dff345518758f13aaeab"
--
2.17.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] openvswitch: fix CVE-2021-36980
2021-09-10 3:21 [PATCH] openvswitch: fix CVE-2021-36980 Zhang, Qiang
@ 2021-09-16 22:07 ` Bruce Ashfield
0 siblings, 0 replies; 2+ messages in thread
From: Bruce Ashfield @ 2021-09-16 22:07 UTC (permalink / raw)
To: qiang.zhang; +Cc: meta-virtualization
In message: [PATCH] openvswitch: fix CVE-2021-36980
on 10/09/2021 qiang.zhang@windriver.com wrote:
> From: Zqiang <qiang.zhang@windriver.com>
>
> Open vSwitch (aka openvswitch) 2.11.0 through 2.15.0 has
> a use-after-free in decode_NXAST_RAW_ENCAP (called from
> ofpact_decode and ofpacts_decode) during the decoding of
> a RAW_ENCAP action.
>
> Reference:
> https://nvd.nist.gov/vuln/detail/CVE-2021-36980
>
> Patches from:
> https://github.com/openvswitch/ovs/commit/65c61b0c23a0d474696d7b1cea522a5016a8aeb3
>
> Signed-off-by: Zqiang <qiang.zhang@windriver.com>
> ---
> ...use-after-free-while-decoding-RAW_EN.patch | 97 +++++++++++++++++++
> .../openvswitch/openvswitch_git.bb | 1 +
> 2 files changed, 98 insertions(+)
> create mode 100644 recipes-networking/openvswitch/files/0001-ofp-actions-Fix-use-after-free-while-decoding-RAW_EN.patch
>
> diff --git a/recipes-networking/openvswitch/files/0001-ofp-actions-Fix-use-after-free-while-decoding-RAW_EN.patch b/recipes-networking/openvswitch/files/0001-ofp-actions-Fix-use-after-free-while-decoding-RAW_EN.patch
> new file mode 100644
> index 00000000..3afd1bad
> --- /dev/null
> +++ b/recipes-networking/openvswitch/files/0001-ofp-actions-Fix-use-after-free-while-decoding-RAW_EN.patch
> @@ -0,0 +1,97 @@
> +From 77cccc74deede443e8b9102299efc869a52b65b2 Mon Sep 17 00:00:00 2001
> +From: Ilya Maximets <i.maximets@ovn.org>
> +Date: Tue, 16 Feb 2021 23:27:30 +0100
> +Subject: [PATCH] ofp-actions: Fix use-after-free while decoding RAW_ENCAP.
> +
> +While decoding RAW_ENCAP action, decode_ed_prop() might re-allocate
> +ofpbuf if there is no enough space left. However, function
> +'decode_NXAST_RAW_ENCAP' continues to use old pointer to 'encap'
> +structure leading to write-after-free and incorrect decoding.
> +
> + ==3549105==ERROR: AddressSanitizer: heap-use-after-free on address
> + 0x60600000011a at pc 0x0000005f6cc6 bp 0x7ffc3a2d4410 sp 0x7ffc3a2d4408
> + WRITE of size 2 at 0x60600000011a thread T0
> + #0 0x5f6cc5 in decode_NXAST_RAW_ENCAP lib/ofp-actions.c:4461:20
> + #1 0x5f0551 in ofpact_decode ./lib/ofp-actions.inc2:4777:16
> + #2 0x5ed17c in ofpacts_decode lib/ofp-actions.c:7752:21
> + #3 0x5eba9a in ofpacts_pull_openflow_actions__ lib/ofp-actions.c:7791:13
> + #4 0x5eb9fc in ofpacts_pull_openflow_actions lib/ofp-actions.c:7835:12
> + #5 0x64bb8b in ofputil_decode_packet_out lib/ofp-packet.c:1113:17
> + #6 0x65b6f4 in ofp_print_packet_out lib/ofp-print.c:148:13
> + #7 0x659e3f in ofp_to_string__ lib/ofp-print.c:1029:16
> + #8 0x659b24 in ofp_to_string lib/ofp-print.c:1244:21
> + #9 0x65a28c in ofp_print lib/ofp-print.c:1288:28
> + #10 0x540d11 in ofctl_ofp_parse utilities/ovs-ofctl.c:2814:9
> + #11 0x564228 in ovs_cmdl_run_command__ lib/command-line.c:247:17
> + #12 0x56408a in ovs_cmdl_run_command lib/command-line.c:278:5
> + #13 0x5391ae in main utilities/ovs-ofctl.c:179:9
> + #14 0x7f6911ce9081 in __libc_start_main (/lib64/libc.so.6+0x27081)
> + #15 0x461fed in _start (utilities/ovs-ofctl+0x461fed)
> +
> +Fix that by getting a new pointer before using.
> +
> +Credit to OSS-Fuzz.
> +
> +Fuzzer regression test will fail only with AddressSanitizer enabled.
> +
> +Reported-at: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=27851
> +Fixes: f839892a206a ("OF support and translation of generic encap and decap")
> +Acked-by: William Tu <u9012063@gmail.com>
> +Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
> +---
> + lib/ofp-actions.c | 2 ++
> + tests/automake.mk | 3 ++-
> + tests/fuzz-regression-list.at | 1 +
> + tests/fuzz-regression/ofp_print_fuzzer-6540965472632832 | 0
> + 4 files changed, 5 insertions(+), 1 deletion(-)
> + create mode 100644 tests/fuzz-regression/ofp_print_fuzzer-6540965472632832
> +
> +diff --git a/lib/ofp-actions.c b/lib/ofp-actions.c
> +index e2e829772..0342a228b 100644
> +--- a/lib/ofp-actions.c
> ++++ b/lib/ofp-actions.c
> +@@ -4431,6 +4431,7 @@ decode_NXAST_RAW_ENCAP(const struct nx_action_encap *nae,
> + {
> + struct ofpact_encap *encap;
> + const struct ofp_ed_prop_header *ofp_prop;
> ++ const size_t encap_ofs = out->size;
> + size_t props_len;
> + uint16_t n_props = 0;
> + int err;
> +@@ -4458,6 +4459,7 @@ decode_NXAST_RAW_ENCAP(const struct nx_action_encap *nae,
> + }
> + n_props++;
> + }
> ++ encap = ofpbuf_at_assert(out, encap_ofs, sizeof *encap);
> + encap->n_props = n_props;
> + out->header = &encap->ofpact;
> + ofpact_finish_ENCAP(out, &encap);
> +diff --git a/tests/automake.mk b/tests/automake.mk
> +index 677b99a6b..fc80e027d 100644
> +--- a/tests/automake.mk
> ++++ b/tests/automake.mk
> +@@ -134,7 +134,8 @@ FUZZ_REGRESSION_TESTS = \
> + tests/fuzz-regression/ofp_print_fuzzer-5722747668791296 \
> + tests/fuzz-regression/ofp_print_fuzzer-6285128790704128 \
> + tests/fuzz-regression/ofp_print_fuzzer-6470117922701312 \
> +- tests/fuzz-regression/ofp_print_fuzzer-6502620041576448
> ++ tests/fuzz-regression/ofp_print_fuzzer-6502620041576448 \
> ++ tests/fuzz-regression/ofp_print_fuzzer-6540965472632832
> + $(srcdir)/tests/fuzz-regression-list.at: tests/automake.mk
> + $(AM_V_GEN)for name in $(FUZZ_REGRESSION_TESTS); do \
> + basename=`echo $$name | sed 's,^.*/,,'`; \
> +diff --git a/tests/fuzz-regression-list.at b/tests/fuzz-regression-list.at
> +index e3173fb88..2347c690e 100644
> +--- a/tests/fuzz-regression-list.at
> ++++ b/tests/fuzz-regression-list.at
> +@@ -21,3 +21,4 @@ TEST_FUZZ_REGRESSION([ofp_print_fuzzer-5722747668791296])
> + TEST_FUZZ_REGRESSION([ofp_print_fuzzer-6285128790704128])
> + TEST_FUZZ_REGRESSION([ofp_print_fuzzer-6470117922701312])
> + TEST_FUZZ_REGRESSION([ofp_print_fuzzer-6502620041576448])
> ++TEST_FUZZ_REGRESSION([ofp_print_fuzzer-6540965472632832])
> +diff --git a/tests/fuzz-regression/ofp_print_fuzzer-6540965472632832 b/tests/fuzz-regression/ofp_print_fuzzer-6540965472632832
> +new file mode 100644
> +index 000000000..e69de29bb
> +--
> +2.17.1
> +
> diff --git a/recipes-networking/openvswitch/openvswitch_git.bb b/recipes-networking/openvswitch/openvswitch_git.bb
> index 1fa7fb2c..4f5454fe 100644
> --- a/recipes-networking/openvswitch/openvswitch_git.bb
> +++ b/recipes-networking/openvswitch/openvswitch_git.bb
> @@ -30,6 +30,7 @@ SRC_URI += "git://github.com/openvswitch/ovs.git;protocol=git;branch=branch-2.15
> file://0001-ovs-use-run-instead-of-var-run-for-in-systemd-units.patch \
> file://0001-openvswitch-fix-do_configure-with-DPDK-19.11-error.patch \
> file://0001-openvswitch-fix-netdev-dpdk-compile-error.patch \
> + file://0001-ofp-actions-Fix-use-after-free-while-decoding-RAW_EN.patch \
You generated this patch against somether other than meta-virtualization
master, since the patches in context of this patch, are not in the recipe.
The patch itself also should have an: Upstream-status: Backport, to help
when we uprev OVS next.
I've sorted out the patch context issue, and added the status. I started
a sanity build of OVS, and have staged this on master-next.
Bruce
> "
>
> LIC_FILES_CHKSUM = "file://LICENSE;md5=1ce5d23a6429dff345518758f13aaeab"
> --
> 2.17.1
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2021-09-10 3:21 [PATCH] openvswitch: fix CVE-2021-36980 Zhang, Qiang
2021-09-16 22:07 ` Bruce Ashfield
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