ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 286 insertions, 0 deletions

diff --git a/net/mac80211/tests/mfp.c b/net/mac80211/tests/mfp.c
new file mode 100644
index 000000000..58e675e0e
--- /dev/null
+++ b/net/mac80211/tests/mfp.c
@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * KUnit tests for management frame acceptance
+ *
+ * Copyright (C) 2023 Intel Corporation
+ */
+#include <kunit/test.h>
+#include <kunit/skbuff.h>
+#include "../ieee80211_i.h"
+#include "../sta_info.h"
+
+MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");
+
+static const struct mfp_test_case {
+	const char *desc;
+	bool sta, mfp, decrypted, unicast, assoc;
+	u8 category;
+	u8 stype;
+	u8 action;
+	ieee80211_rx_result result;
+} accept_mfp_cases[] = {
+	/* regular public action */
+	{
+		.desc = "public action: accept unicast from unknown peer",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_PUBLIC,
+		.action = WLAN_PUB_ACTION_DSE_ENABLEMENT,
+		.unicast = true,
+		.result = RX_CONTINUE,
+	},
+	{
+		.desc = "public action: accept multicast from unknown peer",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_PUBLIC,
+		.action = WLAN_PUB_ACTION_DSE_ENABLEMENT,
+		.unicast = false,
+		.result = RX_CONTINUE,
+	},
+	{
+		.desc = "public action: accept unicast without MFP",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_PUBLIC,
+		.action = WLAN_PUB_ACTION_DSE_ENABLEMENT,
+		.unicast = true,
+		.sta = true,
+		.result = RX_CONTINUE,
+	},
+	{
+		.desc = "public action: accept multicast without MFP",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_PUBLIC,
+		.action = WLAN_PUB_ACTION_DSE_ENABLEMENT,
+		.unicast = false,
+		.sta = true,
+		.result = RX_CONTINUE,
+	},
+	{
+		.desc = "public action: drop unicast with MFP",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_PUBLIC,
+		.action = WLAN_PUB_ACTION_DSE_ENABLEMENT,
+		.unicast = true,
+		.sta = true,
+		.mfp = true,
+		.result = RX_DROP_U_UNPROT_UNICAST_PUB_ACTION,
+	},
+	{
+		.desc = "public action: accept multicast with MFP",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_PUBLIC,
+		.action = WLAN_PUB_ACTION_DSE_ENABLEMENT,
+		.unicast = false,
+		.sta = true,
+		.mfp = true,
+		.result = RX_CONTINUE,
+	},
+	/* protected dual of public action */
+	{
+		.desc = "protected dual: drop unicast from unknown peer",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_PROTECTED_DUAL_OF_ACTION,
+		.action = WLAN_PUB_ACTION_DSE_ENABLEMENT,
+		.unicast = true,
+		.result = RX_DROP_U_UNPROT_DUAL,
+	},
+	{
+		.desc = "protected dual: drop multicast from unknown peer",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_PROTECTED_DUAL_OF_ACTION,
+		.action = WLAN_PUB_ACTION_DSE_ENABLEMENT,
+		.unicast = false,
+		.result = RX_DROP_U_UNPROT_DUAL,
+	},
+	{
+		.desc = "protected dual: drop unicast without MFP",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_PROTECTED_DUAL_OF_ACTION,
+		.action = WLAN_PUB_ACTION_DSE_ENABLEMENT,
+		.unicast = true,
+		.sta = true,
+		.result = RX_DROP_U_UNPROT_DUAL,
+	},
+	{
+		.desc = "protected dual: drop multicast without MFP",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_PROTECTED_DUAL_OF_ACTION,
+		.action = WLAN_PUB_ACTION_DSE_ENABLEMENT,
+		.unicast = false,
+		.sta = true,
+		.result = RX_DROP_U_UNPROT_DUAL,
+	},
+	{
+		.desc = "protected dual: drop undecrypted unicast with MFP",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_PROTECTED_DUAL_OF_ACTION,
+		.action = WLAN_PUB_ACTION_DSE_ENABLEMENT,
+		.unicast = true,
+		.sta = true,
+		.mfp = true,
+		.result = RX_DROP_U_UNPROT_DUAL,
+	},
+	{
+		.desc = "protected dual: drop undecrypted multicast with MFP",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_PROTECTED_DUAL_OF_ACTION,
+		.action = WLAN_PUB_ACTION_DSE_ENABLEMENT,
+		.unicast = false,
+		.sta = true,
+		.mfp = true,
+		.result = RX_DROP_U_UNPROT_DUAL,
+	},
+	{
+		.desc = "protected dual: accept unicast with MFP",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_PROTECTED_DUAL_OF_ACTION,
+		.action = WLAN_PUB_ACTION_DSE_ENABLEMENT,
+		.decrypted = true,
+		.unicast = true,
+		.sta = true,
+		.mfp = true,
+		.result = RX_CONTINUE,
+	},
+	{
+		.desc = "protected dual: accept multicast with MFP",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_PROTECTED_DUAL_OF_ACTION,
+		.action = WLAN_PUB_ACTION_DSE_ENABLEMENT,
+		.decrypted = true,
+		.unicast = false,
+		.sta = true,
+		.mfp = true,
+		.result = RX_CONTINUE,
+	},
+	/* deauth/disassoc before keys are set */
+	{
+		.desc = "deauth: accept unicast with MFP but w/o key",
+		.stype = IEEE80211_STYPE_DEAUTH,
+		.sta = true,
+		.mfp = true,
+		.unicast = true,
+		.result = RX_CONTINUE,
+	},
+	{
+		.desc = "disassoc: accept unicast with MFP but w/o key",
+		.stype = IEEE80211_STYPE_DEAUTH,
+		.sta = true,
+		.mfp = true,
+		.unicast = true,
+		.result = RX_CONTINUE,
+	},
+	/* non-public robust action frame ... */
+	{
+		.desc = "BA action: drop unicast before assoc",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_BACK,
+		.unicast = true,
+		.sta = true,
+		.result = RX_DROP_U_UNPROT_ROBUST_ACTION,
+	},
+	{
+		.desc = "BA action: drop unprotected after assoc",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_BACK,
+		.unicast = true,
+		.sta = true,
+		.mfp = true,
+		.result = RX_DROP_U_UNPROT_UCAST_MGMT,
+	},
+	{
+		.desc = "BA action: accept unprotected without MFP",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_BACK,
+		.unicast = true,
+		.sta = true,
+		.assoc = true,
+		.mfp = false,
+		.result = RX_CONTINUE,
+	},
+	{
+		.desc = "BA action: drop unprotected with MFP",
+		.stype = IEEE80211_STYPE_ACTION,
+		.category = WLAN_CATEGORY_BACK,
+		.unicast = true,
+		.sta = true,
+		.mfp = true,
+		.result = RX_DROP_U_UNPROT_UCAST_MGMT,
+	},
+};
+
+KUNIT_ARRAY_PARAM_DESC(accept_mfp, accept_mfp_cases, desc);
+
+static void accept_mfp(struct kunit *test)
+{
+	static struct sta_info sta;
+	const struct mfp_test_case *params = test->param_value;
+	struct ieee80211_rx_data rx = {
+		.sta = params->sta ? &sta : NULL,
+	};
+	struct ieee80211_rx_status *status;
+	struct ieee80211_hdr_3addr hdr = {
+		.frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
+					     params->stype),
+		.addr1 = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff },
+		.addr2 = { 0x12, 0x22, 0x33, 0x44, 0x55, 0x66 },
+		/* A3/BSSID doesn't matter here */
+	};
+
+	memset(&sta, 0, sizeof(sta));
+
+	if (!params->sta) {
+		KUNIT_ASSERT_FALSE(test, params->mfp);
+		KUNIT_ASSERT_FALSE(test, params->decrypted);
+	}
+
+	if (params->mfp)
+		set_sta_flag(&sta, WLAN_STA_MFP);
+
+	if (params->assoc)
+		set_bit(WLAN_STA_ASSOC, &sta._flags);
+
+	rx.skb = kunit_zalloc_skb(test, 128, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, rx.skb);
+	status = IEEE80211_SKB_RXCB(rx.skb);
+
+	if (params->decrypted) {
+		status->flag |= RX_FLAG_DECRYPTED;
+		if (params->unicast)
+			hdr.frame_control |=
+				cpu_to_le16(IEEE80211_FCTL_PROTECTED);
+	}
+
+	if (params->unicast)
+		hdr.addr1[0] = 0x02;
+
+	skb_put_data(rx.skb, &hdr, sizeof(hdr));
+
+	switch (params->stype) {
+	case IEEE80211_STYPE_ACTION:
+		skb_put_u8(rx.skb, params->category);
+		skb_put_u8(rx.skb, params->action);
+		break;
+	case IEEE80211_STYPE_DEAUTH:
+	case IEEE80211_STYPE_DISASSOC: {
+		__le16 reason = cpu_to_le16(WLAN_REASON_UNSPECIFIED);
+
+		skb_put_data(rx.skb, &reason, sizeof(reason));
+		}
+		break;
+	}
+
+	KUNIT_EXPECT_EQ(test,
+			(__force u32)ieee80211_drop_unencrypted_mgmt(&rx),
+			(__force u32)params->result);
+}
+
+static struct kunit_case mfp_test_cases[] = {
+	KUNIT_CASE_PARAM(accept_mfp, accept_mfp_gen_params),
+	{}
+};
+
+static struct kunit_suite mfp = {
+	.name = "mac80211-mfp",
+	.test_cases = mfp_test_cases,
+};
+
+kunit_test_suite(mfp);