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process_vm_readv

Intro

process_vm_readv - transfer data between the address spaces of two processes.

Description

The process_vm_readv() system call is designed to perform a vectorized read from a specified process's address space, transferring data to another process's address space without the need for intermediate buffers or filesystem-based methods. This is primarily utilized for cross-process memory access, such as debugging tools or some specialized inter-process communication techniques.

Arguments

  • pid:pid_t[K] - Process ID of the target process from which data is to be read.
  • local_iov:struct iovec *[U] - Pointer to an array of iovec structures that determine the local memory segments.
  • liovcnt:unsigned long[K] - Number of elements in local_iov.
  • remote_iov:struct iovec *[U] - Pointer to an array of iovec structures that determine the remote memory segments in the target process.
  • riovcnt:unsigned long[K] - Number of elements in remote_iov.
  • flags:unsigned long[K] - Flag bits to modify operation (usually set to 0).

Available Tags

  • K - Originated from kernel-space.
  • U - Originated from user space.
  • TOCTOU - Vulnerable to TOCTOU (time of check, time of use).
  • OPT - Optional argument - might not always be available (passed with null value).

Hooks

sys_process_vm_readv

Type

Tracepoint (through sys_enter).

Purpose

To monitor and trace when the process_vm_readv() system call is executed, capturing details about the source and target memory regions and the processes involved.

Example Use Case

Building a debugging or monitoring tool that requires direct reading of memory from a target process without inducing significant overhead or relying on file-based methods.

Issues

process_vm_readv() could be exploited in specific scenarios where unauthorized memory access is attempted. Proper permissions and checks should always be in place to avoid unintended data leaks or security implications.

  • process_vm_writev() - Transfer data to the address space of another process.

This document was automatically generated by OpenAI and reviewed by a Human.