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, 219 insertions, 0 deletions

diff --git a/net/mac802154/mib.c b/net/mac802154/mib.c
new file mode 100644
index 000000000..81666e1d7
--- /dev/null
+++ b/net/mac802154/mib.c
@@ -0,0 +1,219 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2007-2012 Siemens AG
+ *
+ * Written by:
+ * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
+ * Sergey Lapin <slapin@ossfans.org>
+ * Maxim Gorbachyov <maxim.gorbachev@siemens.com>
+ * Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
+ */
+
+#include <linux/if_arp.h>
+
+#include <net/mac802154.h>
+#include <net/ieee802154_netdev.h>
+#include <net/cfg802154.h>
+
+#include "ieee802154_i.h"
+#include "driver-ops.h"
+
+void mac802154_dev_set_page_channel(struct net_device *dev, u8 page, u8 chan)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	struct ieee802154_local *local = sdata->local;
+	int res;
+
+	ASSERT_RTNL();
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	res = drv_set_channel(local, page, chan);
+	if (res) {
+		pr_debug("set_channel failed\n");
+	} else {
+		local->phy->current_channel = chan;
+		local->phy->current_page = page;
+	}
+}
+
+int mac802154_get_params(struct net_device *dev,
+			 struct ieee802154_llsec_params *params)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_get_params(&sdata->sec, params);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_set_params(struct net_device *dev,
+			 const struct ieee802154_llsec_params *params,
+			 int changed)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_set_params(&sdata->sec, params, changed);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_add_key(struct net_device *dev,
+		      const struct ieee802154_llsec_key_id *id,
+		      const struct ieee802154_llsec_key *key)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_key_add(&sdata->sec, id, key);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_del_key(struct net_device *dev,
+		      const struct ieee802154_llsec_key_id *id)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_key_del(&sdata->sec, id);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_add_dev(struct net_device *dev,
+		      const struct ieee802154_llsec_device *llsec_dev)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_dev_add(&sdata->sec, llsec_dev);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_del_dev(struct net_device *dev, __le64 dev_addr)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_dev_del(&sdata->sec, dev_addr);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_add_devkey(struct net_device *dev,
+			 __le64 device_addr,
+			 const struct ieee802154_llsec_device_key *key)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_devkey_add(&sdata->sec, device_addr, key);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_del_devkey(struct net_device *dev,
+			 __le64 device_addr,
+			 const struct ieee802154_llsec_device_key *key)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_devkey_del(&sdata->sec, device_addr, key);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_add_seclevel(struct net_device *dev,
+			   const struct ieee802154_llsec_seclevel *sl)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_seclevel_add(&sdata->sec, sl);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_del_seclevel(struct net_device *dev,
+			   const struct ieee802154_llsec_seclevel *sl)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_seclevel_del(&sdata->sec, sl);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+void mac802154_lock_table(struct net_device *dev)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+}
+
+void mac802154_get_table(struct net_device *dev,
+			 struct ieee802154_llsec_table **t)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	*t = &sdata->sec.table;
+}
+
+void mac802154_unlock_table(struct net_device *dev)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_unlock(&sdata->sec_mtx);
+}