KeSetEventPageable (Windows Driver CodeQL Query)

Article
03/12/2024

Overview

KeSetEvent must not be called in a paged segment when the Wait argument is set to TRUE. This can cause a system crash the segment is paged out.

For more information, see KeSetEvent (wdm.h).

Recommendation

Adjust the KeSetEvent call to pass FALSE to the wait parameter.

Example

// Copyright (c) Microsoft Corporation.
// Licensed under the MIT license.
//
// driver_snippet.c
//

#define SET_DISPATCH 1

// Template. Not called in this test.
void top_level_call() {}

#include <wdm.h>

void KeSetEventIrql_Fail1(PRKEVENT Event);

_IRQL_always_function_min_(APC_LEVEL) 
void KeSetEventIrql_Fail2(PRKEVENT Event);

_IRQL_always_function_min_(PASSIVE_LEVEL) 
void KeSetEventIrql_Pass1(PRKEVENT Event);

_IRQL_always_function_min_(PASSIVE_LEVEL) 
void KeSetEventIrql_Pass2(PRKEVENT Event);

#pragma alloc_text(PAGE, KeSetEventIrql_Fail1)
#pragma alloc_text(PAGE, KeSetEventIrql_Fail2)
#pragma alloc_text(PAGE, KeSetEventIrql_Pass2)

void KeSetEventIrql_Fail1(PRKEVENT Event)
{
    // This is a paged function.  We assume a lower limit of PASSIVE_LEVEL and an upper limit of APC_LEVEL on the IRQL.

    KeSetEvent(Event, HIGH_PRIORITY, TRUE); // ERROR: Calling with wait set to TRUE in a pageable context
}

void KeSetEventIrql_Fail2(PRKEVENT Event)
{
    // This is a paged function.  Even though it runs at APC_LEVEL, not PASSIVE_LEVEL, that's still an error.

    KeSetEvent(Event, HIGH_PRIORITY, TRUE); // ERROR: Calling with wait set to TRUE in a pageable context
}

void KeSetEventIrql_Pass1(PRKEVENT Event)
{
    // This function will potentially run at passive level but it's not pageable, so there's no issue.

    KeSetEvent(Event, HIGH_PRIORITY, TRUE);
}

void KeSetEventIrql_Pass2(PRKEVENT Event)
{
    // This function will runs at passive level and is pageable, but correctly uses FALSE in its call to KeSetEvent.

    KeSetEvent(Event, HIGH_PRIORITY, FALSE);
}

// TODO multi-threaded tests
// function has max IRQL requirement, creates two threads where one is above that requirement and one is below

Additional Details

This query can be found in the Microsoft GitHub CodeQL repository. See the CodeQL and the Static Tools Logo Test page for details on how Windows Driver developers can download and run CodeQL.

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