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, 448 insertions, 0 deletions

diff --git a/drivers/android/binder_trace.h b/drivers/android/binder_trace.h
new file mode 100644
index 000000000..fa5eb61cf
--- /dev/null
+++ b/drivers/android/binder_trace.h
@@ -0,0 +1,448 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2012 Google, Inc.
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM binder
+
+#if !defined(_BINDER_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _BINDER_TRACE_H
+
+#include <linux/tracepoint.h>
+
+struct binder_buffer;
+struct binder_node;
+struct binder_proc;
+struct binder_alloc;
+struct binder_ref_data;
+struct binder_thread;
+struct binder_transaction;
+
+TRACE_EVENT(binder_ioctl,
+	TP_PROTO(unsigned int cmd, unsigned long arg),
+	TP_ARGS(cmd, arg),
+
+	TP_STRUCT__entry(
+		__field(unsigned int, cmd)
+		__field(unsigned long, arg)
+	),
+	TP_fast_assign(
+		__entry->cmd = cmd;
+		__entry->arg = arg;
+	),
+	TP_printk("cmd=0x%x arg=0x%lx", __entry->cmd, __entry->arg)
+);
+
+DECLARE_EVENT_CLASS(binder_function_return_class,
+	TP_PROTO(int ret),
+	TP_ARGS(ret),
+	TP_STRUCT__entry(
+		__field(int, ret)
+	),
+	TP_fast_assign(
+		__entry->ret = ret;
+	),
+	TP_printk("ret=%d", __entry->ret)
+);
+
+#define DEFINE_BINDER_FUNCTION_RETURN_EVENT(name)	\
+DEFINE_EVENT(binder_function_return_class, name,	\
+	TP_PROTO(int ret), \
+	TP_ARGS(ret))
+
+DEFINE_BINDER_FUNCTION_RETURN_EVENT(binder_ioctl_done);
+DEFINE_BINDER_FUNCTION_RETURN_EVENT(binder_write_done);
+DEFINE_BINDER_FUNCTION_RETURN_EVENT(binder_read_done);
+
+TRACE_EVENT(binder_wait_for_work,
+	TP_PROTO(bool proc_work, bool transaction_stack, bool thread_todo),
+	TP_ARGS(proc_work, transaction_stack, thread_todo),
+
+	TP_STRUCT__entry(
+		__field(bool, proc_work)
+		__field(bool, transaction_stack)
+		__field(bool, thread_todo)
+	),
+	TP_fast_assign(
+		__entry->proc_work = proc_work;
+		__entry->transaction_stack = transaction_stack;
+		__entry->thread_todo = thread_todo;
+	),
+	TP_printk("proc_work=%d transaction_stack=%d thread_todo=%d",
+		  __entry->proc_work, __entry->transaction_stack,
+		  __entry->thread_todo)
+);
+
+TRACE_EVENT(binder_txn_latency_free,
+	TP_PROTO(struct binder_transaction *t,
+		 int from_proc, int from_thread,
+		 int to_proc, int to_thread),
+	TP_ARGS(t, from_proc, from_thread, to_proc, to_thread),
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(int, from_proc)
+		__field(int, from_thread)
+		__field(int, to_proc)
+		__field(int, to_thread)
+		__field(unsigned int, code)
+		__field(unsigned int, flags)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t->debug_id;
+		__entry->from_proc = from_proc;
+		__entry->from_thread = from_thread;
+		__entry->to_proc = to_proc;
+		__entry->to_thread = to_thread;
+		__entry->code = t->code;
+		__entry->flags = t->flags;
+	),
+	TP_printk("transaction=%d from %d:%d to %d:%d flags=0x%x code=0x%x",
+		  __entry->debug_id, __entry->from_proc, __entry->from_thread,
+		  __entry->to_proc, __entry->to_thread, __entry->code,
+		  __entry->flags)
+);
+
+TRACE_EVENT(binder_transaction,
+	TP_PROTO(bool reply, struct binder_transaction *t,
+		 struct binder_node *target_node),
+	TP_ARGS(reply, t, target_node),
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(int, target_node)
+		__field(int, to_proc)
+		__field(int, to_thread)
+		__field(int, reply)
+		__field(unsigned int, code)
+		__field(unsigned int, flags)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t->debug_id;
+		__entry->target_node = target_node ? target_node->debug_id : 0;
+		__entry->to_proc = t->to_proc->pid;
+		__entry->to_thread = t->to_thread ? t->to_thread->pid : 0;
+		__entry->reply = reply;
+		__entry->code = t->code;
+		__entry->flags = t->flags;
+	),
+	TP_printk("transaction=%d dest_node=%d dest_proc=%d dest_thread=%d reply=%d flags=0x%x code=0x%x",
+		  __entry->debug_id, __entry->target_node,
+		  __entry->to_proc, __entry->to_thread,
+		  __entry->reply, __entry->flags, __entry->code)
+);
+
+TRACE_EVENT(binder_transaction_received,
+	TP_PROTO(struct binder_transaction *t),
+	TP_ARGS(t),
+
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t->debug_id;
+	),
+	TP_printk("transaction=%d", __entry->debug_id)
+);
+
+TRACE_EVENT(binder_transaction_node_to_ref,
+	TP_PROTO(struct binder_transaction *t, struct binder_node *node,
+		 struct binder_ref_data *rdata),
+	TP_ARGS(t, node, rdata),
+
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(int, node_debug_id)
+		__field(binder_uintptr_t, node_ptr)
+		__field(int, ref_debug_id)
+		__field(uint32_t, ref_desc)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t->debug_id;
+		__entry->node_debug_id = node->debug_id;
+		__entry->node_ptr = node->ptr;
+		__entry->ref_debug_id = rdata->debug_id;
+		__entry->ref_desc = rdata->desc;
+	),
+	TP_printk("transaction=%d node=%d src_ptr=0x%016llx ==> dest_ref=%d dest_desc=%d",
+		  __entry->debug_id, __entry->node_debug_id,
+		  (u64)__entry->node_ptr,
+		  __entry->ref_debug_id, __entry->ref_desc)
+);
+
+TRACE_EVENT(binder_transaction_ref_to_node,
+	TP_PROTO(struct binder_transaction *t, struct binder_node *node,
+		 struct binder_ref_data *rdata),
+	TP_ARGS(t, node, rdata),
+
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(int, ref_debug_id)
+		__field(uint32_t, ref_desc)
+		__field(int, node_debug_id)
+		__field(binder_uintptr_t, node_ptr)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t->debug_id;
+		__entry->ref_debug_id = rdata->debug_id;
+		__entry->ref_desc = rdata->desc;
+		__entry->node_debug_id = node->debug_id;
+		__entry->node_ptr = node->ptr;
+	),
+	TP_printk("transaction=%d node=%d src_ref=%d src_desc=%d ==> dest_ptr=0x%016llx",
+		  __entry->debug_id, __entry->node_debug_id,
+		  __entry->ref_debug_id, __entry->ref_desc,
+		  (u64)__entry->node_ptr)
+);
+
+TRACE_EVENT(binder_transaction_ref_to_ref,
+	TP_PROTO(struct binder_transaction *t, struct binder_node *node,
+		 struct binder_ref_data *src_ref,
+		 struct binder_ref_data *dest_ref),
+	TP_ARGS(t, node, src_ref, dest_ref),
+
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(int, node_debug_id)
+		__field(int, src_ref_debug_id)
+		__field(uint32_t, src_ref_desc)
+		__field(int, dest_ref_debug_id)
+		__field(uint32_t, dest_ref_desc)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t->debug_id;
+		__entry->node_debug_id = node->debug_id;
+		__entry->src_ref_debug_id = src_ref->debug_id;
+		__entry->src_ref_desc = src_ref->desc;
+		__entry->dest_ref_debug_id = dest_ref->debug_id;
+		__entry->dest_ref_desc = dest_ref->desc;
+	),
+	TP_printk("transaction=%d node=%d src_ref=%d src_desc=%d ==> dest_ref=%d dest_desc=%d",
+		  __entry->debug_id, __entry->node_debug_id,
+		  __entry->src_ref_debug_id, __entry->src_ref_desc,
+		  __entry->dest_ref_debug_id, __entry->dest_ref_desc)
+);
+
+TRACE_EVENT(binder_transaction_fd_send,
+	TP_PROTO(struct binder_transaction *t, int fd, size_t offset),
+	TP_ARGS(t, fd, offset),
+
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(int, fd)
+		__field(size_t, offset)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t->debug_id;
+		__entry->fd = fd;
+		__entry->offset = offset;
+	),
+	TP_printk("transaction=%d src_fd=%d offset=%zu",
+		  __entry->debug_id, __entry->fd, __entry->offset)
+);
+
+TRACE_EVENT(binder_transaction_fd_recv,
+	TP_PROTO(struct binder_transaction *t, int fd, size_t offset),
+	TP_ARGS(t, fd, offset),
+
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(int, fd)
+		__field(size_t, offset)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t->debug_id;
+		__entry->fd = fd;
+		__entry->offset = offset;
+	),
+	TP_printk("transaction=%d dest_fd=%d offset=%zu",
+		  __entry->debug_id, __entry->fd, __entry->offset)
+);
+
+DECLARE_EVENT_CLASS(binder_buffer_class,
+	TP_PROTO(struct binder_buffer *buf),
+	TP_ARGS(buf),
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(size_t, data_size)
+		__field(size_t, offsets_size)
+		__field(size_t, extra_buffers_size)
+	),
+	TP_fast_assign(
+		__entry->debug_id = buf->debug_id;
+		__entry->data_size = buf->data_size;
+		__entry->offsets_size = buf->offsets_size;
+		__entry->extra_buffers_size = buf->extra_buffers_size;
+	),
+	TP_printk("transaction=%d data_size=%zd offsets_size=%zd extra_buffers_size=%zd",
+		  __entry->debug_id, __entry->data_size, __entry->offsets_size,
+		  __entry->extra_buffers_size)
+);
+
+DEFINE_EVENT(binder_buffer_class, binder_transaction_alloc_buf,
+	TP_PROTO(struct binder_buffer *buffer),
+	TP_ARGS(buffer));
+
+DEFINE_EVENT(binder_buffer_class, binder_transaction_buffer_release,
+	TP_PROTO(struct binder_buffer *buffer),
+	TP_ARGS(buffer));
+
+DEFINE_EVENT(binder_buffer_class, binder_transaction_failed_buffer_release,
+	TP_PROTO(struct binder_buffer *buffer),
+	TP_ARGS(buffer));
+
+DEFINE_EVENT(binder_buffer_class, binder_transaction_update_buffer_release,
+	     TP_PROTO(struct binder_buffer *buffer),
+	     TP_ARGS(buffer));
+
+TRACE_EVENT(binder_update_page_range,
+	TP_PROTO(struct binder_alloc *alloc, bool allocate,
+		 unsigned long start, unsigned long end),
+	TP_ARGS(alloc, allocate, start, end),
+	TP_STRUCT__entry(
+		__field(int, proc)
+		__field(bool, allocate)
+		__field(size_t, offset)
+		__field(size_t, size)
+	),
+	TP_fast_assign(
+		__entry->proc = alloc->pid;
+		__entry->allocate = allocate;
+		__entry->offset = start - alloc->vm_start;
+		__entry->size = end - start;
+	),
+	TP_printk("proc=%d allocate=%d offset=%zu size=%zu",
+		  __entry->proc, __entry->allocate,
+		  __entry->offset, __entry->size)
+);
+
+DECLARE_EVENT_CLASS(binder_lru_page_class,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index),
+	TP_STRUCT__entry(
+		__field(int, proc)
+		__field(size_t, page_index)
+	),
+	TP_fast_assign(
+		__entry->proc = alloc->pid;
+		__entry->page_index = page_index;
+	),
+	TP_printk("proc=%d page_index=%zu",
+		  __entry->proc, __entry->page_index)
+);
+
+DEFINE_EVENT(binder_lru_page_class, binder_alloc_lru_start,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_alloc_lru_end,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_free_lru_start,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_free_lru_end,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_alloc_page_start,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_alloc_page_end,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_unmap_user_start,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_unmap_user_end,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_unmap_kernel_start,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_unmap_kernel_end,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+TRACE_EVENT(binder_command,
+	TP_PROTO(uint32_t cmd),
+	TP_ARGS(cmd),
+	TP_STRUCT__entry(
+		__field(uint32_t, cmd)
+	),
+	TP_fast_assign(
+		__entry->cmd = cmd;
+	),
+	TP_printk("cmd=0x%x %s",
+		  __entry->cmd,
+		  _IOC_NR(__entry->cmd) < ARRAY_SIZE(binder_command_strings) ?
+			  binder_command_strings[_IOC_NR(__entry->cmd)] :
+			  "unknown")
+);
+
+TRACE_EVENT(binder_return,
+	TP_PROTO(uint32_t cmd),
+	TP_ARGS(cmd),
+	TP_STRUCT__entry(
+		__field(uint32_t, cmd)
+	),
+	TP_fast_assign(
+		__entry->cmd = cmd;
+	),
+	TP_printk("cmd=0x%x %s",
+		  __entry->cmd,
+		  _IOC_NR(__entry->cmd) < ARRAY_SIZE(binder_return_strings) ?
+			  binder_return_strings[_IOC_NR(__entry->cmd)] :
+			  "unknown")
+);
+
+TRACE_EVENT(binder_netlink_report,
+	TP_PROTO(const char *context,
+		 struct binder_transaction *t,
+		 u32 data_size,
+		 u32 error),
+	TP_ARGS(context, t, data_size, error),
+	TP_STRUCT__entry(
+		__field(const char *, context)
+		__field(u32, error)
+		__field(int, from_pid)
+		__field(int, from_tid)
+		__field(int, to_pid)
+		__field(int, to_tid)
+		__field(bool, is_reply)
+		__field(unsigned int, flags)
+		__field(unsigned int, code)
+		__field(size_t, data_size)
+	),
+	TP_fast_assign(
+		__entry->context = context;
+		__entry->error = error;
+		__entry->from_pid = t->from_pid;
+		__entry->from_tid = t->from_tid;
+		__entry->to_pid = t->to_proc ? t->to_proc->pid : 0;
+		__entry->to_tid = t->to_thread ? t->to_thread->pid : 0;
+		__entry->is_reply = t->is_reply;
+		__entry->flags = t->flags;
+		__entry->code = t->code;
+		__entry->data_size = data_size;
+	),
+	TP_printk("from %d:%d to %d:%d context=%s error=%d is_reply=%d flags=0x%x code=0x%x size=%zu",
+		  __entry->from_pid, __entry->from_tid,
+		  __entry->to_pid, __entry->to_tid,
+		  __entry->context, __entry->error, __entry->is_reply,
+		  __entry->flags, __entry->code, __entry->data_size)
+);
+
+#endif /* _BINDER_TRACE_H */
+
+#undef TRACE_INCLUDE_PATH
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE binder_trace
+#include <trace/define_trace.h>