From a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 Mon Sep 17 00:00:00 2001 From: Jinke Han Date: Tue, 8 Sep 2026 15:37:42 +0800 Subject: x86/kprobes: Fix crash when probing CS CALL instructions 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) Signed-off-by: Jinke Han Signed-off-by: Ingo Molnar Reviewed-by: Masami Hiramatsu (Google) Acked-by: Yafang Shao Acked-by: Borislav Petkov Cc: Peter Zijlstra Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000 --- net/bluetooth/Kconfig | 148 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 148 insertions(+) create mode 100644 net/bluetooth/Kconfig (limited to 'net/bluetooth/Kconfig') diff --git a/net/bluetooth/Kconfig b/net/bluetooth/Kconfig new file mode 100644 index 000000000..1cda01614 --- /dev/null +++ b/net/bluetooth/Kconfig @@ -0,0 +1,148 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Bluetooth subsystem configuration +# + +menuconfig BT + tristate "Bluetooth subsystem support" + depends on !S390 + depends on RFKILL || !RFKILL + select CRC16 + select CRYPTO + select CRYPTO_LIB_AES + select CRYPTO_LIB_AES_CBC_MACS + select CRYPTO_ECDH + help + Bluetooth is low-cost, low-power, short-range wireless technology. + It was designed as a replacement for cables and other short-range + technologies like IrDA. Bluetooth operates in personal area range + that typically extends up to 10 meters. More information about + Bluetooth can be found at . + + Linux Bluetooth subsystem consist of several layers: + Bluetooth Core + HCI device and connection manager, scheduler + SCO audio links + L2CAP (Logical Link Control and Adaptation Protocol) + SMP (Security Manager Protocol) on LE (Low Energy) links + ISO isochronous links + HCI Device drivers (Interface to the hardware) + RFCOMM Module (RFCOMM Protocol) + BNEP Module (Bluetooth Network Encapsulation Protocol) + HIDP Module (Human Interface Device Protocol) + + Say Y here to compile Bluetooth support into the kernel or say M to + compile it as module (bluetooth). + + To use Linux Bluetooth subsystem, you will need several user-space + utilities like hciconfig and bluetoothd. These utilities and updates + to Bluetooth kernel modules are provided in the BlueZ packages. For + more information, see . + +config BT_BREDR + bool "Bluetooth Classic (BR/EDR) features" + depends on BT + default y + help + Bluetooth Classic includes support for Basic Rate (BR) + available with Bluetooth version 1.0b or later and support + for Enhanced Data Rate (EDR) available with Bluetooth + version 2.0 or later. + +source "net/bluetooth/rfcomm/Kconfig" + +source "net/bluetooth/bnep/Kconfig" + +source "net/bluetooth/hidp/Kconfig" + +config BT_LE + bool "Bluetooth Low Energy (LE) features" + depends on BT + default y + help + Bluetooth Low Energy includes support low-energy physical + layer available with Bluetooth version 4.0 or later. + +config BT_LE_L2CAP_ECRED + bool "Bluetooth L2CAP Enhanced Credit Flow Control" + depends on BT_LE + default y + help + Bluetooth Low Energy L2CAP Enhanced Credit Flow Control available with + Bluetooth version 5.2 or later. + + This can be overridden by passing bluetooth.enable_ecred=[1|0] + on the kernel commandline. + +config BT_6LOWPAN + tristate "Bluetooth 6LoWPAN support" + depends on BT && BT_LE && 6LOWPAN + help + IPv6 compression over Bluetooth Low Energy. + +config BT_LEDS + bool "Enable LED triggers" + depends on BT + depends on LEDS_CLASS + select LEDS_TRIGGERS + help + This option selects a few LED triggers for different + Bluetooth events. + +config BT_MSFTEXT + bool "Enable Microsoft extensions" + depends on BT + help + This options enables support for the Microsoft defined HCI + vendor extensions. + +config BT_AOSPEXT + bool "Enable Android Open Source Project extensions" + depends on BT + help + This options enables support for the Android Open Source + Project defined HCI vendor extensions. + +config BT_DEBUGFS + bool "Export Bluetooth internals in debugfs" + depends on BT && DEBUG_FS + default y + help + Provide extensive information about internal Bluetooth states + in debugfs. + +config BT_SELFTEST + bool "Bluetooth self testing support" + depends on BT && DEBUG_KERNEL + help + Run self tests when initializing the Bluetooth subsystem. This + is a developer option and can cause significant delay when booting + the system. + + When the Bluetooth subsystem is built as module, then the test + cases are run first thing at module load time. When the Bluetooth + subsystem is compiled into the kernel image, then the test cases + are run late in the initcall hierarchy. + +config BT_SELFTEST_ECDH + bool "ECDH test cases" + depends on BT_LE && BT_SELFTEST + help + Run test cases for ECDH cryptographic functionality used by the + Bluetooth Low Energy Secure Connections feature. + +config BT_SELFTEST_SMP + bool "SMP test cases" + depends on BT_LE && BT_SELFTEST + help + Run test cases for SMP cryptographic functionality, including both + legacy SMP as well as the Secure Connections features. + +config BT_FEATURE_DEBUG + bool "Enable runtime option for debugging statements" + depends on BT && !DYNAMIC_DEBUG + help + This provides an option to enable/disable debugging statements + at runtime via the experimental features interface. + +source "drivers/bluetooth/Kconfig" -- cgit v1.3.1