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getxattr

Intro

getxattr - retrieves the value of the extended attribute identified by name and associated with the given path in the file system.

Description

The getxattr() system call gets the value of an extended attribute identified by name and associated with the given path in the file system. It is intended to be a companion to the setxattr(2) system call, which sets extended attributes.

There are a number of advantages and edge-cases to using getxattr(). One major advantage is that extended attributes can store data not defined by standard file attributes, such as security labels and access control lists, and more. Furthermore, the value and size of an extended attribute may change from one call to the next, with certain flags and options. This makes getxattr() a useful tool for implementing certain security schemes that require precise control over data.

A potential issue with using getxattr() is that it is vulnerable to Time of Check to Time of Use (TOCTOU) race conditions, which can be problematic for security-enhanced applications.

Arguments

  • path:const char*[KU] - the relative or absolute path name of the file or directory.
  • name:const char*[KU] - the name of the attribute to retrieve.
  • value:void*[K] - a buffer to store the attribute's value.
  • size:size_t[K] - the size of the buffer (size of the attribute's value).

Available Tags

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

Hooks

getxattr

Type

Kprobe + Kretprobe

Purpose

To monitor and audit when getxattr() system calls occur and what their associated arguments are.

Example Use Case

getxattr() can be used to determine the value of security labels or access control lists on files and directories. This is often necessary for implementing robust security systems for applications that must maintain the integrity of the data on the system.

Issues

getxattr() is vulnerable to TOCTOU race conditions, which can result in unintended side-effects if not handled correctly.

setxattr(2)

This document was automatically generated by OpenAI and needs review. It might not be accurate and might contain errors. The authors of Tracee recommend that the user reads the "events.go" source file to understand the events and their arguments better.