[PATCH AUTOSEL 6.6 09/21] selftests: openvswitch: Add validation for the recursion test

Sasha Levin
2024-02-29T15:50:05Z

From: Aaron Conole <aconole@redhat.com>

[ Upstream commit bd128f62c365504e1268dc09fcccdfb1f091e93a ]

Add a test case into the netlink checks that will show the number of
nested action recursions won't exceed 16. Going to 17 on a small
clone call isn't enough to exhaust the stack on (most) systems, so
it should be safe to run even on systems that don't have the fix
applied.

Signed-off-by: Aaron Conole <aconole@redhat.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240207132416.1488485-3-aconole@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../selftests/net/openvswitch/openvswitch.sh | 13 ++++
.../selftests/net/openvswitch/ovs-dpctl.py | 71 +++++++++++++++----
2 files changed, 69 insertions(+), 15 deletions(-)

diff --git a/tools/testing/selftests/net/openvswitch/openvswitch.sh b/tools/testing/selftests/net/openvswitch/openvswitch.sh
index f8499d4c87f3f..36e40256ab92a 100755
--- a/tools/testing/selftests/net/openvswitch/openvswitch.sh
+++ b/tools/testing/selftests/net/openvswitch/openvswitch.sh
@@ -502,7 +502,20 @@ test_netlink_checks () {
wc -l) == 2 ] || \
return 1

+ info "Checking clone depth"
ERR_MSG="Flow actions may not be safe on all matching packets"
+ PRE_TEST=$(dmesg | grep -c "${ERR_MSG}")
+ ovs_add_flow "test_netlink_checks" nv0 \
+ 'in_port(1),eth(),eth_type(0x800),ipv4()' \
+ 'clone(clone(clone(clone(clone(clone(clone(clone(clone(clone(clone(clone(clone(clone(clone(clone(clone(drop)))))))))))))))))' \
+ >/dev/null 2>&1 && return 1
+ POST_TEST=$(dmesg | grep -c "${ERR_MSG}")
+
+ if [ "$PRE_TEST" == "$POST_TEST" ]; then
+ info "failed - clone depth too large"
+ return 1
+ fi
+
PRE_TEST=$(dmesg | grep -c "${ERR_MSG}")
ovs_add_flow "test_netlink_checks" nv0 \
'in_port(1),eth(),eth_type(0x0806),arp()' 'drop(0),2' \
diff --git a/tools/testing/selftests/net/openvswitch/ovs-dpctl.py b/tools/testing/selftests/net/openvswitch/ovs-dpctl.py
index b97e621face95..5e0e539a323d5 100644
--- a/tools/testing/selftests/net/openvswitch/ovs-dpctl.py
+++ b/tools/testing/selftests/net/openvswitch/ovs-dpctl.py
@@ -299,7 +299,7 @@ class ovsactions(nla):
("OVS_ACTION_ATTR_PUSH_NSH", "none"),
("OVS_ACTION_ATTR_POP_NSH", "flag"),
("OVS_ACTION_ATTR_METER", "none"),
- ("OVS_ACTION_ATTR_CLONE", "none"),
+ ("OVS_ACTION_ATTR_CLONE", "recursive"),
("OVS_ACTION_ATTR_CHECK_PKT_LEN", "none"),
("OVS_ACTION_ATTR_ADD_MPLS", "none"),
("OVS_ACTION_ATTR_DEC_TTL", "none"),
@@ -465,29 +465,42 @@ class ovsactions(nla):
print_str += "pop_mpls"
else:
datum = self.get_attr(field[0])
- print_str += datum.dpstr(more)
+ if field[0] == "OVS_ACTION_ATTR_CLONE":
+ print_str += "clone("
+ print_str += datum.dpstr(more)
+ print_str += ")"
+ else:
+ print_str += datum.dpstr(more)

return print_str

def parse(self, actstr):
+ totallen = len(actstr)
while len(actstr) != 0:
parsed = False
+ parencount = 0
if actstr.startswith("drop"):
# If no reason is provided, the implicit drop is used (i.e no
# action). If some reason is given, an explicit action is used.
- actstr, reason = parse_extract_field(
- actstr,
- "drop(",
- "([0-9]+)",
- lambda x: int(x, 0),
- False,
- None,
- )
+ reason = None
+ if actstr.startswith("drop("):
+ parencount += 1
+
+ actstr, reason = parse_extract_field(
+ actstr,
+ "drop(",
+ "([0-9]+)",
+ lambda x: int(x, 0),
+ False,
+ None,
+ )
+
if reason is not None:
self["attrs"].append(["OVS_ACTION_ATTR_DROP", reason])
parsed = True
else:
- return
+ actstr = actstr[len("drop"): ]
+ return (totallen - len(actstr))

elif parse_starts_block(actstr, "^(\d+)", False, True):
actstr, output = parse_extract_field(
@@ -504,6 +517,7 @@ class ovsactions(nla):
False,
0,
)
+ parencount += 1
self["attrs"].append(["OVS_ACTION_ATTR_RECIRC", recircid])
parsed = True

@@ -516,12 +530,22 @@ class ovsactions(nla):

for flat_act in parse_flat_map:
if parse_starts_block(actstr, flat_act[0], False):
- actstr += len(flat_act[0])
+ actstr = actstr[len(flat_act[0]):]
self["attrs"].append([flat_act[1]])
actstr = actstr[strspn(actstr, ", ") :]
parsed = True

- if parse_starts_block(actstr, "ct(", False):
+ if parse_starts_block(actstr, "clone(", False):
+ parencount += 1
+ subacts = ovsactions()
+ actstr = actstr[len("clone("):]
+ parsedLen = subacts.parse(actstr)
+ lst = []
+ self["attrs"].append(("OVS_ACTION_ATTR_CLONE", subacts))
+ actstr = actstr[parsedLen:]
+ parsed = True
+ elif parse_starts_block(actstr, "ct(", False):
+ parencount += 1
actstr = actstr[len("ct(") :]
ctact = ovsactions.ctact()

@@ -553,6 +577,7 @@ class ovsactions(nla):
natact = ovsactions.ctact.natattr()

if actstr.startswith("("):
+ parencount += 1
t = None
actstr = actstr[1:]
if actstr.startswith("src"):
@@ -607,15 +632,29 @@ class ovsactions(nla):
actstr = actstr[strspn(actstr, ", ") :]

ctact["attrs"].append(["OVS_CT_ATTR_NAT", natact])
- actstr = actstr[strspn(actstr, ",) ") :]
+ actstr = actstr[strspn(actstr, ", ") :]

self["attrs"].append(["OVS_ACTION_ATTR_CT", ctact])
parsed = True

- actstr = actstr[strspn(actstr, "), ") :]
+ actstr = actstr[strspn(actstr, ", ") :]
+ while parencount > 0:
+ parencount -= 1
+ actstr = actstr[strspn(actstr, " "):]
+ if len(actstr) and actstr[0] != ")":
+ raise ValueError("Action str: '%s' unbalanced" % actstr)
+ actstr = actstr[1:]
+
+ if len(actstr) and actstr[0] == ")":
+ return (totallen - len(actstr))
+
+ actstr = actstr[strspn(actstr, ", ") :]
+
if not parsed:
raise ValueError("Action str: '%s' not supported" % actstr)

+ return (totallen - len(actstr))
+

class ovskey(nla):
nla_flags = NLA_F_NESTED
@@ -2111,6 +2150,8 @@ def main(argv):
ovsflow = OvsFlow()
ndb = NDB()

+ sys.setrecursionlimit(100000)
+
if hasattr(args, "showdp"):
found = False
for iface in ndb.interfaces:
--
2.43.0