x86/kprobes: Fix crash when probing CS CALL instructionsgrafted

When using eBPF to probe CS CALL instructions within a function,
a crash can be triggered.

The eBPF tool probes offset 257 of the __hrtimer_run_queues()
function:

<__hrtimer_run_queues+249>:  nopl   0x0(%rax,%rax,1)
<__hrtimer_run_queues+254>:  mov    %r14,%rdi
<__hrtimer_run_queues+257>:  cs call <__x86_indirect_thunk_r12>
<__hrtimer_run_queues+263>:  mov    %eax,%r12d
<__hrtimer_run_queues+266>:  xchg   %ax,%ax
<__hrtimer_run_queues+268>:  mov    %r13,%rdi

Which triggers this crash:

  BUG: unable to handle page fault for address: 00000000000f41c9
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0
  Oops: 0002 [#1] SMP NOPTI
  CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P
  RIP: 0010:__hrtimer_run_queues+0x106/0x230

Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is
at the 6th byte of the above CS CALL instruction. Since the CS CALL
instruction occupies 6 bytes, the exception occurred in the middle of that
call instruction.

The root cause is that when using eBPF tools to probe in the middle of a
function, a kprobe with INT3 is used as the underlying implementation.

During single-step emulation of the original CALL instruction,
int3_emulate_call() assumes that the probed CALL instruction is 5 bytes
long. However, the actual CS-prefixed CALL instruction occupies 6 bytes,
so it constructs an incorrect exception return address. When the CPU
returns from the kprobe handler, the next instruction to be executed is at
the address of the last byte of that CS CALL instruction. Coincidentally,
starting from that address, the CPU fetches and decodes a completely
different instruction, which ultimately triggers a kernel crash.

Fix the issue by using the actual instruction length obtained from
the instruction decoder when constructing the exception return
address, rather than relying on the hardcoded CALL_INSN_SIZE macro.

[ mingo: Refined the changelog ]

Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000

1 files changed, 999 insertions, 0 deletions

diff --git a/net/wireless/tests/scan.c b/net/wireless/tests/scan.c
new file mode 100644
index 000000000..8c20278b5
--- /dev/null
+++ b/net/wireless/tests/scan.c
@@ -0,0 +1,999 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * KUnit tests for inform_bss functions
+ *
+ * Copyright (C) 2023-2024 Intel Corporation
+ */
+#include <linux/ieee80211.h>
+#include <net/cfg80211.h>
+#include <kunit/test.h>
+#include <kunit/skbuff.h>
+#include "../core.h"
+#include "util.h"
+
+/* mac80211 helpers for element building */
+#include "../../mac80211/ieee80211_i.h"
+
+MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");
+
+struct test_elem {
+	u8 id;
+	u8 len;
+	union {
+		u8 data[255];
+		struct {
+			u8 eid;
+			u8 edata[254];
+		};
+	};
+};
+
+static struct gen_new_ie_case {
+	const char *desc;
+	struct test_elem parent_ies[16];
+	struct test_elem child_ies[16];
+	struct test_elem result_ies[16];
+} gen_new_ie_cases[] = {
+	{
+		.desc = "ML not inherited",
+		.parent_ies = {
+			{ .id = WLAN_EID_EXTENSION, .len = 255,
+			  .eid = WLAN_EID_EXT_EHT_MULTI_LINK },
+		},
+		.child_ies = {
+			{ .id = WLAN_EID_SSID, .len = 2 },
+		},
+		.result_ies = {
+			{ .id = WLAN_EID_SSID, .len = 2 },
+		},
+	},
+	{
+		.desc = "fragments are ignored if previous len not 255",
+		.parent_ies = {
+			{ .id = WLAN_EID_REDUCED_NEIGHBOR_REPORT, .len = 254, },
+			{ .id = WLAN_EID_FRAGMENT, .len = 125, },
+		},
+		.child_ies = {
+			{ .id = WLAN_EID_SSID, .len = 2 },
+			{ .id = WLAN_EID_FRAGMENT, .len = 125, },
+		},
+		.result_ies = {
+			{ .id = WLAN_EID_REDUCED_NEIGHBOR_REPORT, .len = 254, },
+			{ .id = WLAN_EID_SSID, .len = 2 },
+		},
+	},
+	{
+		.desc = "fragments inherited",
+		.parent_ies = {
+			{ .id = WLAN_EID_REDUCED_NEIGHBOR_REPORT, .len = 255, },
+			{ .id = WLAN_EID_FRAGMENT, .len = 125, },
+		},
+		.child_ies = {
+			{ .id = WLAN_EID_SSID, .len = 2 },
+		},
+		.result_ies = {
+			{ .id = WLAN_EID_REDUCED_NEIGHBOR_REPORT, .len = 255, },
+			{ .id = WLAN_EID_FRAGMENT, .len = 125, },
+			{ .id = WLAN_EID_SSID, .len = 2 },
+		},
+	},
+	{
+		.desc = "fragments copied",
+		.parent_ies = {
+			{ .id = WLAN_EID_REDUCED_NEIGHBOR_REPORT, .len = 255, },
+			{ .id = WLAN_EID_FRAGMENT, .len = 125, },
+		},
+		.child_ies = {
+			{ .id = WLAN_EID_SSID, .len = 2 },
+		},
+		.result_ies = {
+			{ .id = WLAN_EID_REDUCED_NEIGHBOR_REPORT, .len = 255, },
+			{ .id = WLAN_EID_FRAGMENT, .len = 125, },
+			{ .id = WLAN_EID_SSID, .len = 2 },
+		},
+	},
+	{
+		.desc = "multiple elements inherit",
+		.parent_ies = {
+			{ .id = WLAN_EID_REDUCED_NEIGHBOR_REPORT, .len = 255, },
+			{ .id = WLAN_EID_FRAGMENT, .len = 125, },
+			{ .id = WLAN_EID_REDUCED_NEIGHBOR_REPORT, .len = 123, },
+		},
+		.child_ies = {
+			{ .id = WLAN_EID_SSID, .len = 2 },
+		},
+		.result_ies = {
+			{ .id = WLAN_EID_REDUCED_NEIGHBOR_REPORT, .len = 255, },
+			{ .id = WLAN_EID_FRAGMENT, .len = 125, },
+			{ .id = WLAN_EID_REDUCED_NEIGHBOR_REPORT, .len = 123, },
+			{ .id = WLAN_EID_SSID, .len = 2 },
+		},
+	},
+	{
+		.desc = "one child element overrides",
+		.parent_ies = {
+			{ .id = WLAN_EID_REDUCED_NEIGHBOR_REPORT, .len = 255, },
+			{ .id = WLAN_EID_FRAGMENT, .len = 125, },
+			{ .id = WLAN_EID_REDUCED_NEIGHBOR_REPORT, .len = 123, },
+		},
+		.child_ies = {
+			{ .id = WLAN_EID_REDUCED_NEIGHBOR_REPORT, .len = 127, },
+			{ .id = WLAN_EID_SSID, .len = 2 },
+		},
+		.result_ies = {
+			{ .id = WLAN_EID_REDUCED_NEIGHBOR_REPORT, .len = 127, },
+			{ .id = WLAN_EID_SSID, .len = 2 },
+		},
+	},
+	{
+		.desc = "empty elements from parent",
+		.parent_ies = {
+			{ .id = 0x1, .len = 0, },
+			{ .id = WLAN_EID_EXTENSION, .len = 1, .eid = 0x10 },
+		},
+		.child_ies = {
+		},
+		.result_ies = {
+			{ .id = 0x1, .len = 0, },
+			{ .id = WLAN_EID_EXTENSION, .len = 1, .eid = 0x10 },
+		},
+	},
+	{
+		.desc = "empty elements from child",
+		.parent_ies = {
+		},
+		.child_ies = {
+			{ .id = 0x1, .len = 0, },
+			{ .id = WLAN_EID_EXTENSION, .len = 1, .eid = 0x10 },
+		},
+		.result_ies = {
+			{ .id = 0x1, .len = 0, },
+			{ .id = WLAN_EID_EXTENSION, .len = 1, .eid = 0x10 },
+		},
+	},
+	{
+		.desc = "invalid extended elements ignored",
+		.parent_ies = {
+			{ .id = WLAN_EID_EXTENSION, .len = 0 },
+		},
+		.child_ies = {
+			{ .id = WLAN_EID_EXTENSION, .len = 0 },
+		},
+		.result_ies = {
+		},
+	},
+	{
+		.desc = "multiple extended elements",
+		.parent_ies = {
+			{ .id = WLAN_EID_EXTENSION, .len = 3,
+			  .eid = WLAN_EID_EXT_HE_CAPABILITY },
+			{ .id = WLAN_EID_EXTENSION, .len = 5,
+			  .eid = WLAN_EID_EXT_ASSOC_DELAY_INFO },
+			{ .id = WLAN_EID_EXTENSION, .len = 7,
+			  .eid = WLAN_EID_EXT_HE_OPERATION },
+			{ .id = WLAN_EID_EXTENSION, .len = 11,
+			  .eid = WLAN_EID_EXT_FILS_REQ_PARAMS },
+		},
+		.child_ies = {
+			{ .id = WLAN_EID_SSID, .len = 13 },
+			{ .id = WLAN_EID_EXTENSION, .len = 17,
+			  .eid = WLAN_EID_EXT_HE_CAPABILITY },
+			{ .id = WLAN_EID_EXTENSION, .len = 11,
+			  .eid = WLAN_EID_EXT_FILS_KEY_CONFIRM },
+			{ .id = WLAN_EID_EXTENSION, .len = 19,
+			  .eid = WLAN_EID_EXT_HE_OPERATION },
+		},
+		.result_ies = {
+			{ .id = WLAN_EID_EXTENSION, .len = 17,
+			  .eid = WLAN_EID_EXT_HE_CAPABILITY },
+			{ .id = WLAN_EID_EXTENSION, .len = 5,
+			  .eid = WLAN_EID_EXT_ASSOC_DELAY_INFO },
+			{ .id = WLAN_EID_EXTENSION, .len = 19,
+			  .eid = WLAN_EID_EXT_HE_OPERATION },
+			{ .id = WLAN_EID_EXTENSION, .len = 11,
+			  .eid = WLAN_EID_EXT_FILS_REQ_PARAMS },
+			{ .id = WLAN_EID_SSID, .len = 13 },
+			{ .id = WLAN_EID_EXTENSION, .len = 11,
+			  .eid = WLAN_EID_EXT_FILS_KEY_CONFIRM },
+		},
+	},
+	{
+		.desc = "non-inherit element",
+		.parent_ies = {
+			{ .id = 0x1, .len = 7, },
+			{ .id = 0x2, .len = 11, },
+			{ .id = 0x3, .len = 13, },
+			{ .id = WLAN_EID_EXTENSION, .len = 17, .eid = 0x10 },
+			{ .id = WLAN_EID_EXTENSION, .len = 19, .eid = 0x11 },
+			{ .id = WLAN_EID_EXTENSION, .len = 23, .eid = 0x12 },
+			{ .id = WLAN_EID_EXTENSION, .len = 29, .eid = 0x14 },
+		},
+		.child_ies = {
+			{ .id = WLAN_EID_EXTENSION,
+			  .eid = WLAN_EID_EXT_NON_INHERITANCE,
+			  .len = 10,
+			  .edata = { 0x3, 0x1, 0x2, 0x3,
+				     0x4, 0x10, 0x11, 0x13, 0x14 } },
+			{ .id = WLAN_EID_SSID, .len = 2 },
+		},
+		.result_ies = {
+			{ .id = WLAN_EID_EXTENSION, .len = 23, .eid = 0x12 },
+			{ .id = WLAN_EID_SSID, .len = 2 },
+		},
+	},
+};
+KUNIT_ARRAY_PARAM_DESC(gen_new_ie, gen_new_ie_cases, desc)
+
+static void test_gen_new_ie(struct kunit *test)
+{
+	const struct gen_new_ie_case *params = test->param_value;
+	struct sk_buff *parent = kunit_zalloc_skb(test, 1024, GFP_KERNEL);
+	struct sk_buff *child = kunit_zalloc_skb(test, 1024, GFP_KERNEL);
+	struct sk_buff *reference = kunit_zalloc_skb(test, 1024, GFP_KERNEL);
+	u8 *out = kunit_kzalloc(test, IEEE80211_MAX_DATA_LEN, GFP_KERNEL);
+	size_t len;
+	int i;
+
+	KUNIT_ASSERT_NOT_NULL(test, parent);
+	KUNIT_ASSERT_NOT_NULL(test, child);
+	KUNIT_ASSERT_NOT_NULL(test, reference);
+	KUNIT_ASSERT_NOT_NULL(test, out);
+
+	for (i = 0; i < ARRAY_SIZE(params->parent_ies); i++) {
+		if (params->parent_ies[i].len != 0) {
+			skb_put_u8(parent, params->parent_ies[i].id);
+			skb_put_u8(parent, params->parent_ies[i].len);
+			skb_put_data(parent, params->parent_ies[i].data,
+				     params->parent_ies[i].len);
+		}
+
+		if (params->child_ies[i].len != 0) {
+			skb_put_u8(child, params->child_ies[i].id);
+			skb_put_u8(child, params->child_ies[i].len);
+			skb_put_data(child, params->child_ies[i].data,
+				     params->child_ies[i].len);
+		}
+
+		if (params->result_ies[i].len != 0) {
+			skb_put_u8(reference, params->result_ies[i].id);
+			skb_put_u8(reference, params->result_ies[i].len);
+			skb_put_data(reference, params->result_ies[i].data,
+				     params->result_ies[i].len);
+		}
+	}
+
+	len = cfg80211_gen_new_ie(parent->data, parent->len,
+				  child->data, child->len,
+				  out, IEEE80211_MAX_DATA_LEN);
+	KUNIT_EXPECT_EQ(test, len, reference->len);
+	KUNIT_EXPECT_MEMEQ(test, out, reference->data, reference->len);
+	memset(out, 0, IEEE80211_MAX_DATA_LEN);
+
+	/* Exactly enough space */
+	len = cfg80211_gen_new_ie(parent->data, parent->len,
+				  child->data, child->len,
+				  out, reference->len);
+	KUNIT_EXPECT_EQ(test, len, reference->len);
+	KUNIT_EXPECT_MEMEQ(test, out, reference->data, reference->len);
+	memset(out, 0, IEEE80211_MAX_DATA_LEN);
+
+	/* Not enough space (or expected zero length) */
+	len = cfg80211_gen_new_ie(parent->data, parent->len,
+				  child->data, child->len,
+				  out, reference->len - 1);
+	KUNIT_EXPECT_EQ(test, len, 0);
+}
+
+static void test_gen_new_ie_malformed(struct kunit *test)
+{
+	struct sk_buff *malformed = kunit_zalloc_skb(test, 1024, GFP_KERNEL);
+	u8 *out = kunit_kzalloc(test, IEEE80211_MAX_DATA_LEN, GFP_KERNEL);
+	size_t len;
+
+	KUNIT_ASSERT_NOT_NULL(test, malformed);
+	KUNIT_ASSERT_NOT_NULL(test, out);
+
+	skb_put_u8(malformed, WLAN_EID_SSID);
+	skb_put_u8(malformed, 3);
+	skb_put(malformed, 3);
+	skb_put_u8(malformed, WLAN_EID_REDUCED_NEIGHBOR_REPORT);
+	skb_put_u8(malformed, 10);
+	skb_put(malformed, 9);
+
+	len = cfg80211_gen_new_ie(malformed->data, malformed->len,
+				  out, 0,
+				  out, IEEE80211_MAX_DATA_LEN);
+	KUNIT_EXPECT_EQ(test, len, 5);
+
+	len = cfg80211_gen_new_ie(out, 0,
+				  malformed->data, malformed->len,
+				  out, IEEE80211_MAX_DATA_LEN);
+	KUNIT_EXPECT_EQ(test, len, 5);
+}
+
+struct inform_bss {
+	struct kunit *test;
+
+	int inform_bss_count;
+};
+
+static void inform_bss_inc_counter(struct wiphy *wiphy,
+				   struct cfg80211_bss *bss,
+				   const struct cfg80211_bss_ies *ies,
+				   void *drv_data)
+{
+	struct inform_bss *ctx = t_wiphy_ctx(wiphy);
+
+	ctx->inform_bss_count++;
+
+	rcu_read_lock();
+	KUNIT_EXPECT_PTR_EQ(ctx->test, drv_data, ctx);
+	KUNIT_EXPECT_PTR_EQ(ctx->test, ies, rcu_dereference(bss->ies));
+	rcu_read_unlock();
+}
+
+static void test_inform_bss_ssid_only(struct kunit *test)
+{
+	struct inform_bss ctx = {
+		.test = test,
+	};
+	struct wiphy *wiphy = T_WIPHY(test, ctx);
+	struct t_wiphy_priv *w_priv = wiphy_priv(wiphy);
+	struct cfg80211_inform_bss inform_bss = {
+		.signal = 50,
+		.drv_data = &ctx,
+	};
+	const u8 bssid[ETH_ALEN] = { 0x10, 0x22, 0x33, 0x44, 0x55, 0x66 };
+	u64 tsf = 0x1000000000000000ULL;
+	int beacon_int = 100;
+	u16 capability = 0x1234;
+	static const u8 input[] = {
+		[0] = WLAN_EID_SSID,
+		[1] = 4,
+		[2] = 'T', 'E', 'S', 'T'
+	};
+	struct cfg80211_bss *bss, *other;
+	const struct cfg80211_bss_ies *ies;
+
+	w_priv->ops->inform_bss = inform_bss_inc_counter;
+
+	inform_bss.chan = ieee80211_get_channel_khz(wiphy, MHZ_TO_KHZ(2412));
+	KUNIT_ASSERT_NOT_NULL(test, inform_bss.chan);
+
+	bss = cfg80211_inform_bss_data(wiphy, &inform_bss,
+				       CFG80211_BSS_FTYPE_PRESP, bssid, tsf,
+				       capability, beacon_int,
+				       input, sizeof(input),
+				       GFP_KERNEL);
+	KUNIT_EXPECT_NOT_NULL(test, bss);
+	KUNIT_EXPECT_EQ(test, ctx.inform_bss_count, 1);
+
+	/* Check values in returned bss are correct */
+	KUNIT_EXPECT_EQ(test, bss->signal, inform_bss.signal);
+	KUNIT_EXPECT_EQ(test, bss->beacon_interval, beacon_int);
+	KUNIT_EXPECT_EQ(test, bss->capability, capability);
+	KUNIT_EXPECT_EQ(test, bss->bssid_index, 0);
+	KUNIT_EXPECT_PTR_EQ(test, bss->channel, inform_bss.chan);
+	KUNIT_EXPECT_MEMEQ(test, bssid, bss->bssid, sizeof(bssid));
+
+	/* Check the IEs have the expected value */
+	rcu_read_lock();
+	ies = rcu_dereference(bss->ies);
+	KUNIT_EXPECT_NOT_NULL(test, ies);
+	KUNIT_EXPECT_EQ(test, ies->tsf, tsf);
+	KUNIT_EXPECT_EQ(test, ies->len, sizeof(input));
+	KUNIT_EXPECT_MEMEQ(test, ies->data, input, sizeof(input));
+	rcu_read_unlock();
+
+	/* Check we can look up the BSS - by SSID */
+	other = cfg80211_get_bss(wiphy, NULL, NULL, "TEST", 4,
+				 IEEE80211_BSS_TYPE_ANY,
+				 IEEE80211_PRIVACY_ANY);
+	KUNIT_EXPECT_PTR_EQ(test, bss, other);
+	cfg80211_put_bss(wiphy, other);
+
+	/* Check we can look up the BSS - by BSSID */
+	other = cfg80211_get_bss(wiphy, NULL, bssid, NULL, 0,
+				 IEEE80211_BSS_TYPE_ANY,
+				 IEEE80211_PRIVACY_ANY);
+	KUNIT_EXPECT_PTR_EQ(test, bss, other);
+	cfg80211_put_bss(wiphy, other);
+
+	cfg80211_put_bss(wiphy, bss);
+}
+
+static void test_get_bss_miss_reason(struct kunit *test)
+{
+	struct inform_bss ctx = {
+		.test = test,
+	};
+	struct wiphy *wiphy = T_WIPHY(test, ctx);
+	struct cfg80211_inform_bss inform_bss = {
+		.signal = 50,
+		.drv_data = &ctx,
+	};
+	const u8 bssid[ETH_ALEN] = { 0x10, 0x22, 0x33, 0x44, 0x55, 0x66 };
+	const u8 other_bssid[ETH_ALEN] = { 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 };
+	static const u8 ies[] = {
+		[0] = WLAN_EID_SSID,
+		[1] = 4,
+		[2] = 'T', 'E', 'S', 'T'
+	};
+	struct cfg80211_internal_bss *ibss;
+	struct netlink_ext_ack extack = {};
+	struct cfg80211_bss *bss, *bss2, *found;
+
+	inform_bss.chan = ieee80211_get_channel_khz(wiphy, MHZ_TO_KHZ(2412));
+	KUNIT_ASSERT_NOT_NULL(test, inform_bss.chan);
+
+	bss = cfg80211_inform_bss_data(wiphy, &inform_bss,
+				       CFG80211_BSS_FTYPE_PRESP, bssid, 0,
+				       0x1234, 100, ies, sizeof(ies),
+				       GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, bss);
+	ibss = container_of(bss, struct cfg80211_internal_bss, pub);
+
+	/* Fresh usable entry: found, no message is set */
+	found = __cfg80211_get_bss(wiphy, NULL, bssid, NULL, 0,
+				   IEEE80211_BSS_TYPE_ANY,
+				   IEEE80211_PRIVACY_ANY,
+				   NL80211_BSS_USE_FOR_NORMAL, &extack);
+	KUNIT_ASSERT_PTR_EQ(test, found, bss);
+	KUNIT_EXPECT_NULL(test, extack._msg);
+	cfg80211_put_bss(wiphy, found);
+
+	/* No entry at all for this BSSID */
+	found = __cfg80211_get_bss(wiphy, NULL, other_bssid, NULL, 0,
+				   IEEE80211_BSS_TYPE_ANY,
+				   IEEE80211_PRIVACY_ANY,
+				   NL80211_BSS_USE_FOR_NORMAL, &extack);
+	KUNIT_EXPECT_NULL(test, found);
+	KUNIT_EXPECT_STREQ(test, extack._msg, "BSS not found in scan results");
+
+	/* Fresh entry that is not usable for the requested use */
+	extack._msg = NULL;
+	bss->use_for = 0;
+	found = __cfg80211_get_bss(wiphy, NULL, bssid, NULL, 0,
+				   IEEE80211_BSS_TYPE_ANY,
+				   IEEE80211_PRIVACY_ANY,
+				   NL80211_BSS_USE_FOR_NORMAL, &extack);
+	KUNIT_EXPECT_NULL(test, found);
+	KUNIT_EXPECT_STREQ(test, extack._msg,
+			   "BSS cannot be used for the requested operation");
+	bss->use_for = NL80211_BSS_USE_FOR_ALL;
+
+	/* Expired entry, > IEEE80211_SCAN_RESULT_EXPIRE (30s) old */
+	extack._msg = NULL;
+	ibss->ts = jiffies - 60 * HZ;
+	found = __cfg80211_get_bss(wiphy, NULL, bssid, NULL, 0,
+				   IEEE80211_BSS_TYPE_ANY,
+				   IEEE80211_PRIVACY_ANY,
+				   NL80211_BSS_USE_FOR_NORMAL, &extack);
+	KUNIT_EXPECT_NULL(test, found);
+	KUNIT_EXPECT_STREQ(test, extack._msg,
+			   "BSS entry in scan results is expired");
+
+	/* An entry both expired and unusable reports expired */
+	extack._msg = NULL;
+	bss->use_for = 0;
+	found = __cfg80211_get_bss(wiphy, NULL, bssid, NULL, 0,
+				   IEEE80211_BSS_TYPE_ANY,
+				   IEEE80211_PRIVACY_ANY,
+				   NL80211_BSS_USE_FOR_NORMAL, &extack);
+	KUNIT_EXPECT_NULL(test, found);
+	KUNIT_EXPECT_STREQ(test, extack._msg,
+			   "BSS entry in scan results is expired");
+	bss->use_for = NL80211_BSS_USE_FOR_ALL;
+
+	/* Expired but held entries are still usable, no message is set */
+	extack._msg = NULL;
+	atomic_set(&ibss->hold, 1);
+	found = __cfg80211_get_bss(wiphy, NULL, bssid, NULL, 0,
+				   IEEE80211_BSS_TYPE_ANY,
+				   IEEE80211_PRIVACY_ANY,
+				   NL80211_BSS_USE_FOR_NORMAL, &extack);
+	KUNIT_ASSERT_PTR_EQ(test, found, bss);
+	KUNIT_EXPECT_NULL(test, extack._msg);
+	cfg80211_put_bss(wiphy, found);
+	atomic_set(&ibss->hold, 0);
+
+	/*
+	 * With one matching entry expired and another current but
+	 * unusable, both reasons are reported.
+	 */
+	bss2 = cfg80211_inform_bss_data(wiphy, &inform_bss,
+					CFG80211_BSS_FTYPE_PRESP, other_bssid,
+					0, 0x1234, 100, ies, sizeof(ies),
+					GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, bss2);
+	bss2->use_for = 0;
+	extack._msg = NULL;
+	found = __cfg80211_get_bss(wiphy, NULL, NULL, "TEST", 4,
+				   IEEE80211_BSS_TYPE_ANY,
+				   IEEE80211_PRIVACY_ANY,
+				   NL80211_BSS_USE_FOR_NORMAL, &extack);
+	KUNIT_EXPECT_NULL(test, found);
+	KUNIT_EXPECT_STREQ(test, extack._msg,
+			   "BSS entries are expired or cannot be used for the requested operation");
+
+	cfg80211_put_bss(wiphy, bss2);
+	cfg80211_put_bss(wiphy, bss);
+}
+
+static struct inform_bss_ml_sta_case {
+	const char *desc;
+	int mld_id;
+	bool sta_prof_vendor_elems;
+	bool include_oper_class;
+	bool nstr;
+} inform_bss_ml_sta_cases[] = {
+	{
+		.desc = "zero_mld_id",
+		.mld_id = 0,
+		.sta_prof_vendor_elems = false,
+	}, {
+		.desc = "zero_mld_id_with_oper_class",
+		.mld_id = 0,
+		.sta_prof_vendor_elems = false,
+		.include_oper_class = true,
+	}, {
+		.desc = "mld_id_eq_1",
+		.mld_id = 1,
+		.sta_prof_vendor_elems = true,
+	}, {
+		.desc = "mld_id_eq_1_with_oper_class",
+		.mld_id = 1,
+		.sta_prof_vendor_elems = true,
+		.include_oper_class = true,
+	}, {
+		.desc = "nstr",
+		.mld_id = 0,
+		.nstr = true,
+	},
+};
+KUNIT_ARRAY_PARAM_DESC(inform_bss_ml_sta, inform_bss_ml_sta_cases, desc)
+
+static void test_inform_bss_ml_sta(struct kunit *test)
+{
+	const struct inform_bss_ml_sta_case *params = test->param_value;
+	struct inform_bss ctx = {
+		.test = test,
+	};
+	struct wiphy *wiphy = T_WIPHY(test, ctx);
+	struct t_wiphy_priv *w_priv = wiphy_priv(wiphy);
+	struct cfg80211_inform_bss inform_bss = {
+		.signal = 50,
+		.drv_data = &ctx,
+	};
+	struct cfg80211_bss *bss, *link_bss;
+	const struct cfg80211_bss_ies *ies;
+
+	/* sending station */
+	const u8 bssid[ETH_ALEN] = { 0x10, 0x22, 0x33, 0x44, 0x55, 0x66 };
+	u64 tsf = 0x1000000000000000ULL;
+	int beacon_int = 100;
+	u16 capability = 0x1234;
+
+	/* Building the frame *************************************************/
+	struct sk_buff *input = kunit_zalloc_skb(test, 1024, GFP_KERNEL);
+	u8 *len_mle, *len_prof;
+	u8 link_id = 2;
+	struct {
+		struct ieee80211_neighbor_ap_info info;
+		struct ieee80211_tbtt_info_ge_11 ap;
+	} __packed rnr_normal = {
+		.info = {
+			.tbtt_info_hdr = u8_encode_bits(0, IEEE80211_AP_INFO_TBTT_HDR_COUNT),
+			.tbtt_info_len = sizeof(struct ieee80211_tbtt_info_ge_11),
+			.op_class = 81,
+			.channel = 11,
+		},
+		.ap = {
+			.tbtt_offset = 0xff,
+			.bssid = { 0x10, 0x22, 0x33, 0x44, 0x55, 0x67 },
+			.short_ssid = 0, /* unused */
+			.bss_params = 0,
+			.psd_20 = 0,
+			.mld_params.mld_id = params->mld_id,
+			.mld_params.params =
+				le16_encode_bits(link_id,
+						 IEEE80211_RNR_MLD_PARAMS_LINK_ID),
+		}
+	};
+	struct {
+		struct ieee80211_neighbor_ap_info info;
+		struct ieee80211_rnr_mld_params mld_params;
+	} __packed rnr_nstr = {
+		.info = {
+			.tbtt_info_hdr =
+				u8_encode_bits(0, IEEE80211_AP_INFO_TBTT_HDR_COUNT) |
+				u8_encode_bits(IEEE80211_TBTT_INFO_TYPE_MLD,
+					       IEEE80211_AP_INFO_TBTT_HDR_TYPE),
+			.tbtt_info_len = sizeof(struct ieee80211_rnr_mld_params),
+			.op_class = 81,
+			.channel = 11,
+		},
+		.mld_params = {
+			.mld_id = params->mld_id,
+			.params =
+				le16_encode_bits(link_id,
+						 IEEE80211_RNR_MLD_PARAMS_LINK_ID),
+		}
+	};
+	size_t rnr_len = params->nstr ? sizeof(rnr_nstr) : sizeof(rnr_normal);
+	void *rnr = params->nstr ? (void *)&rnr_nstr : (void *)&rnr_normal;
+	struct {
+		__le16 control;
+		u8 var_len;
+		u8 mld_mac_addr[ETH_ALEN];
+		u8 link_id_info;
+		u8 params_change_count;
+		__le16 mld_caps_and_ops;
+		u8 mld_id;
+		__le16 ext_mld_caps_and_ops;
+	} __packed mle_basic_common_info = {
+		.control =
+			cpu_to_le16(IEEE80211_ML_CONTROL_TYPE_BASIC |
+				    IEEE80211_MLC_BASIC_PRES_BSS_PARAM_CH_CNT |
+				    IEEE80211_MLC_BASIC_PRES_LINK_ID |
+				    (params->mld_id ? IEEE80211_MLC_BASIC_PRES_MLD_ID : 0) |
+				    IEEE80211_MLC_BASIC_PRES_MLD_CAPA_OP),
+		.mld_id = params->mld_id,
+		.mld_caps_and_ops = cpu_to_le16(0x0102),
+		.ext_mld_caps_and_ops = cpu_to_le16(0x0304),
+		.var_len = sizeof(mle_basic_common_info) - 2 -
+			   (params->mld_id ? 0 : 1),
+		.mld_mac_addr = { 0x10, 0x22, 0x33, 0x44, 0x55, 0x60 },
+	};
+	struct {
+		__le16 control;
+		u8 var_len;
+		u8 bssid[ETH_ALEN];
+		__le16 beacon_int;
+		__le64 tsf_offset;
+		__le16 capabilities; /* already part of payload */
+	} __packed sta_prof = {
+		.control =
+			cpu_to_le16(IEEE80211_MLE_STA_CONTROL_COMPLETE_PROFILE |
+				    IEEE80211_MLE_STA_CONTROL_STA_MAC_ADDR_PRESENT |
+				    IEEE80211_MLE_STA_CONTROL_BEACON_INT_PRESENT |
+				    IEEE80211_MLE_STA_CONTROL_TSF_OFFS_PRESENT |
+				    u16_encode_bits(link_id,
+						    IEEE80211_MLE_STA_CONTROL_LINK_ID)),
+		.var_len = sizeof(sta_prof) - 2 - 2,
+		.bssid = { *rnr_normal.ap.bssid },
+		.beacon_int = cpu_to_le16(101),
+		.tsf_offset = cpu_to_le64(-123ll),
+		.capabilities = cpu_to_le16(0xdead),
+	};
+
+	KUNIT_ASSERT_NOT_NULL(test, input);
+
+	w_priv->ops->inform_bss = inform_bss_inc_counter;
+
+	inform_bss.chan = ieee80211_get_channel_khz(wiphy, MHZ_TO_KHZ(2412));
+	KUNIT_ASSERT_NOT_NULL(test, inform_bss.chan);
+
+	skb_put_u8(input, WLAN_EID_SSID);
+	skb_put_u8(input, 4);
+	skb_put_data(input, "TEST", 4);
+
+	if (params->include_oper_class) {
+		skb_put_u8(input, WLAN_EID_SUPPORTED_REGULATORY_CLASSES);
+		skb_put_u8(input, 1);
+		skb_put_u8(input, 81);
+	}
+
+	skb_put_u8(input, WLAN_EID_REDUCED_NEIGHBOR_REPORT);
+	skb_put_u8(input, rnr_len);
+	skb_put_data(input, rnr, rnr_len);
+
+	/* build a multi-link element */
+	skb_put_u8(input, WLAN_EID_EXTENSION);
+	len_mle = skb_put(input, 1);
+	skb_put_u8(input, WLAN_EID_EXT_EHT_MULTI_LINK);
+	skb_put_data(input, &mle_basic_common_info, sizeof(mle_basic_common_info));
+	if (!params->mld_id)
+		t_skb_remove_member(input, typeof(mle_basic_common_info), mld_id);
+	/* with a STA profile inside */
+	skb_put_u8(input, IEEE80211_MLE_SUBELEM_PER_STA_PROFILE);
+	len_prof = skb_put(input, 1);
+	skb_put_data(input, &sta_prof, sizeof(sta_prof));
+
+	if (params->sta_prof_vendor_elems) {
+		/* Put two (vendor) element into sta_prof */
+		skb_put_u8(input, WLAN_EID_VENDOR_SPECIFIC);
+		skb_put_u8(input, 160);
+		skb_put(input, 160);
+
+		skb_put_u8(input, WLAN_EID_VENDOR_SPECIFIC);
+		skb_put_u8(input, 165);
+		skb_put(input, 165);
+	}
+
+	/* fragment STA profile */
+	ieee80211_fragment_element(input, len_prof,
+				   IEEE80211_MLE_SUBELEM_FRAGMENT);
+	/* fragment MLE */
+	ieee80211_fragment_element(input, len_mle, WLAN_EID_FRAGMENT);
+
+	/* Put a (vendor) element after the ML element */
+	skb_put_u8(input, WLAN_EID_VENDOR_SPECIFIC);
+	skb_put_u8(input, 155);
+	skb_put(input, 155);
+
+	/* Submit *************************************************************/
+	bss = cfg80211_inform_bss_data(wiphy, &inform_bss,
+				       CFG80211_BSS_FTYPE_PRESP, bssid, tsf,
+				       capability, beacon_int,
+				       input->data, input->len,
+				       GFP_KERNEL);
+	KUNIT_EXPECT_NOT_NULL(test, bss);
+	KUNIT_EXPECT_EQ(test, ctx.inform_bss_count, 2);
+
+	/* Check link_bss *****************************************************/
+	link_bss = __cfg80211_get_bss(wiphy, NULL, sta_prof.bssid, NULL, 0,
+				      IEEE80211_BSS_TYPE_ANY,
+				      IEEE80211_PRIVACY_ANY,
+				      0, NULL);
+	KUNIT_ASSERT_NOT_NULL(test, link_bss);
+	KUNIT_EXPECT_EQ(test, link_bss->signal, 0);
+	KUNIT_EXPECT_EQ(test, link_bss->beacon_interval,
+			      le16_to_cpu(sta_prof.beacon_int));
+	KUNIT_EXPECT_EQ(test, link_bss->capability,
+			      le16_to_cpu(sta_prof.capabilities));
+	KUNIT_EXPECT_EQ(test, link_bss->bssid_index, 0);
+	KUNIT_EXPECT_PTR_EQ(test, link_bss->channel,
+			    ieee80211_get_channel_khz(wiphy, MHZ_TO_KHZ(2462)));
+
+	/* Test wiphy does not set WIPHY_FLAG_SUPPORTS_NSTR_NONPRIMARY */
+	if (params->nstr) {
+		KUNIT_EXPECT_EQ(test, link_bss->use_for, 0);
+		KUNIT_EXPECT_EQ(test, link_bss->cannot_use_reasons,
+				NL80211_BSS_CANNOT_USE_NSTR_NONPRIMARY);
+		KUNIT_EXPECT_NULL(test,
+				  cfg80211_get_bss(wiphy, NULL, sta_prof.bssid,
+						   NULL, 0,
+						   IEEE80211_BSS_TYPE_ANY,
+						   IEEE80211_PRIVACY_ANY));
+	} else {
+		KUNIT_EXPECT_EQ(test, link_bss->use_for,
+				NL80211_BSS_USE_FOR_ALL);
+		KUNIT_EXPECT_EQ(test, link_bss->cannot_use_reasons, 0);
+	}
+
+	rcu_read_lock();
+	ies = rcu_dereference(link_bss->ies);
+	KUNIT_EXPECT_NOT_NULL(test, ies);
+	KUNIT_EXPECT_EQ(test, ies->tsf, tsf + le64_to_cpu(sta_prof.tsf_offset));
+	/* Resulting length should be:
+	 * SSID (inherited) + RNR (inherited) + vendor element(s) +
+	 * operating class (if requested) +
+	 * generated RNR (if MLD ID == 0 and not NSTR) +
+	 * MLE common info + MLE header and control
+	 */
+	if (params->sta_prof_vendor_elems)
+		KUNIT_EXPECT_EQ(test, ies->len,
+				6 + 2 + rnr_len + 2 + 160 + 2 + 165 +
+				(params->include_oper_class ? 3 : 0) +
+				(!params->mld_id && !params->nstr ? 22 : 0) +
+				mle_basic_common_info.var_len + 5);
+	else
+		KUNIT_EXPECT_EQ(test, ies->len,
+				6 + 2 + rnr_len + 2 + 155 +
+				(params->include_oper_class ? 3 : 0) +
+				(!params->mld_id && !params->nstr ? 22 : 0) +
+				mle_basic_common_info.var_len + 5);
+	rcu_read_unlock();
+
+	cfg80211_put_bss(wiphy, bss);
+	cfg80211_put_bss(wiphy, link_bss);
+}
+
+static struct cfg80211_parse_colocated_ap_case {
+	const char *desc;
+	u8 op_class;
+	u8 channel;
+	struct ieee80211_neighbor_ap_info info;
+	union {
+		struct ieee80211_tbtt_info_ge_11 tbtt_long;
+		struct ieee80211_tbtt_info_7_8_9 tbtt_short;
+	};
+	bool add_junk;
+	bool same_ssid;
+	bool valid;
+} cfg80211_parse_colocated_ap_cases[] = {
+	{
+		.desc = "wrong_band",
+		.info.op_class = 81,
+		.info.channel = 11,
+		.tbtt_long = {
+			.bssid = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP,
+		},
+		.valid = false,
+	},
+	{
+		.desc = "wrong_type",
+		/* IEEE80211_AP_INFO_TBTT_HDR_TYPE is in the least significant bits */
+		.info.tbtt_info_hdr = IEEE80211_TBTT_INFO_TYPE_MLD,
+		.tbtt_long = {
+			.bssid = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP,
+		},
+		.valid = false,
+	},
+	{
+		.desc = "colocated_invalid_len_short",
+		.info.tbtt_info_len = 6,
+		.tbtt_short = {
+			.bssid = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP |
+				      IEEE80211_RNR_TBTT_PARAMS_SAME_SSID,
+		},
+		.valid = false,
+	},
+	{
+		.desc = "colocated_invalid_len_short_mld",
+		.info.tbtt_info_len = 10,
+		.tbtt_long = {
+			.bssid = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP,
+		},
+		.valid = false,
+	},
+	{
+		.desc = "colocated_non_mld",
+		.info.tbtt_info_len = sizeof(struct ieee80211_tbtt_info_7_8_9),
+		.tbtt_short = {
+			.bssid = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP |
+				      IEEE80211_RNR_TBTT_PARAMS_SAME_SSID,
+		},
+		.same_ssid = true,
+		.valid = true,
+	},
+	{
+		.desc = "colocated_non_mld_invalid_bssid",
+		.info.tbtt_info_len = sizeof(struct ieee80211_tbtt_info_7_8_9),
+		.tbtt_short = {
+			.bssid = { 0xff, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP |
+				      IEEE80211_RNR_TBTT_PARAMS_SAME_SSID,
+		},
+		.same_ssid = true,
+		.valid = false,
+	},
+	{
+		.desc = "colocated_mld",
+		.tbtt_long = {
+			.bssid = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP,
+		},
+		.valid = true,
+	},
+	{
+		.desc = "colocated_mld",
+		.tbtt_long = {
+			.bssid = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP,
+		},
+		.add_junk = true,
+		.valid = false,
+	},
+	{
+		.desc = "colocated_disabled_mld",
+		.tbtt_long = {
+			.bssid = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP,
+			.mld_params.params = cpu_to_le16(IEEE80211_RNR_MLD_PARAMS_DISABLED_LINK),
+		},
+		.valid = false,
+	},
+};
+KUNIT_ARRAY_PARAM_DESC(cfg80211_parse_colocated_ap, cfg80211_parse_colocated_ap_cases, desc)
+
+static void test_cfg80211_parse_colocated_ap(struct kunit *test)
+{
+	const struct cfg80211_parse_colocated_ap_case *params = test->param_value;
+	struct sk_buff *input = kunit_zalloc_skb(test, 1024, GFP_KERNEL);
+	struct cfg80211_bss_ies *ies;
+	struct ieee80211_neighbor_ap_info info;
+	LIST_HEAD(coloc_ap_list);
+	int count;
+
+	KUNIT_ASSERT_NOT_NULL(test, input);
+
+	info = params->info;
+
+	/* Reasonable values for a colocated AP */
+	if (!info.tbtt_info_len)
+		info.tbtt_info_len = sizeof(params->tbtt_long);
+	if (!info.op_class)
+		info.op_class = 131;
+	if (!info.channel)
+		info.channel = 33;
+	/* Zero is the correct default for .btt_info_hdr (one entry, TBTT type) */
+
+	skb_put_u8(input, WLAN_EID_SSID);
+	skb_put_u8(input, 4);
+	skb_put_data(input, "TEST", 4);
+
+	skb_put_u8(input, WLAN_EID_REDUCED_NEIGHBOR_REPORT);
+	skb_put_u8(input, sizeof(info) + info.tbtt_info_len + (params->add_junk ? 3 : 0));
+	skb_put_data(input, &info, sizeof(info));
+	skb_put_data(input, &params->tbtt_long, info.tbtt_info_len);
+
+	if (params->add_junk)
+		skb_put_data(input, "123", 3);
+
+	ies = kunit_kzalloc(test, struct_size(ies, data, input->len), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, ies);
+
+	ies->len = input->len;
+	memcpy(ies->data, input->data, input->len);
+
+	count = cfg80211_parse_colocated_ap(ies, &coloc_ap_list);
+
+	KUNIT_EXPECT_EQ(test, count, params->valid);
+	KUNIT_EXPECT_EQ(test, list_count_nodes(&coloc_ap_list), params->valid);
+
+	if (params->valid && !list_empty(&coloc_ap_list)) {
+		struct cfg80211_colocated_ap *ap;
+
+		ap = list_first_entry(&coloc_ap_list, typeof(*ap), list);
+		if (info.tbtt_info_len <= sizeof(params->tbtt_short))
+			KUNIT_EXPECT_MEMEQ(test, ap->bssid, params->tbtt_short.bssid, ETH_ALEN);
+		else
+			KUNIT_EXPECT_MEMEQ(test, ap->bssid, params->tbtt_long.bssid, ETH_ALEN);
+
+		if (params->same_ssid) {
+			KUNIT_EXPECT_EQ(test, ap->ssid_len, 4);
+			KUNIT_EXPECT_MEMEQ(test, ap->ssid, "TEST", 4);
+		} else {
+			KUNIT_EXPECT_EQ(test, ap->ssid_len, 0);
+		}
+	}
+
+	cfg80211_free_coloc_ap_list(&coloc_ap_list);
+}
+
+static struct kunit_case gen_new_ie_test_cases[] = {
+	KUNIT_CASE_PARAM(test_gen_new_ie, gen_new_ie_gen_params),
+	KUNIT_CASE(test_gen_new_ie_malformed),
+	{}
+};
+
+static struct kunit_suite gen_new_ie = {
+	.name = "cfg80211-ie-generation",
+	.test_cases = gen_new_ie_test_cases,
+};
+
+kunit_test_suite(gen_new_ie);
+
+static struct kunit_case inform_bss_test_cases[] = {
+	KUNIT_CASE(test_inform_bss_ssid_only),
+	KUNIT_CASE(test_get_bss_miss_reason),
+	KUNIT_CASE_PARAM(test_inform_bss_ml_sta, inform_bss_ml_sta_gen_params),
+	{}
+};
+
+static struct kunit_suite inform_bss = {
+	.name = "cfg80211-inform-bss",
+	.test_cases = inform_bss_test_cases,
+};
+
+kunit_test_suite(inform_bss);
+
+static struct kunit_case scan_6ghz_cases[] = {
+	KUNIT_CASE_PARAM(test_cfg80211_parse_colocated_ap,
+			 cfg80211_parse_colocated_ap_gen_params),
+	{}
+};
+
+static struct kunit_suite scan_6ghz = {
+	.name = "cfg80211-scan-6ghz",
+	.test_cases = scan_6ghz_cases,
+};
+
+kunit_test_suite(scan_6ghz);