#include "lixcrash.h"
#include "alerts.h"
#include "decoder.h"
#include "guests.h"
#include "lixksym.h"

Data Structures
struct	_PRINTK_LOG_HEADER
	Linux 'struct printk_log' buffer header. More...

Macros
#define	MAX_STACKTRACES 16

#define	MAX_FUNC_NAME 128

#define	MAX_LOG_SIZE 512

#define	PREFIX_MAX 32

#define	LOG_LINE_MAX (1024 - PREFIX_MAX)

#define	LIX_SIGNAL_STOP_MASK
	The signal for STOP action. More...

#define	LIX_SIGNAL_IGNORE_MASK
	The signal for IGNORE action. More...

#define	LIX_SIGNAL_FATAL(sig) !((sig) > 0 && (sig) < SIGRTMIN && (BIT(sig) & (LIX_SIGNAL_IGNORE_MASK \| LIX_SIGNAL_STOP_MASK)))
	Check if the provided signal is fatal. More...

Typedefs
typedef struct _PRINTK_LOG_HEADER	PRINTK_LOG_HEADER
	Linux 'struct printk_log' buffer header. More...

typedef struct _PRINTK_LOG_HEADER *	PPRINTK_LOG_HEADER

Functions
static INTSTATUS	IntLixCrashSendPanicEvent (void)
	Send an event, if the operating system crashed, that contains information about the task that generated the crash. More...

static INTSTATUS	IntLixCrashFetchDmesgSymbol (QWORD LogBufferGva, QWORD LogBufferLengthGva, QWORD *LogFirstIdxGva)
	Find the address of the symbols 'log_buf', 'log_buf_len' and 'log_first_idx'. More...

static BOOLEAN	IntLixCrashEnoughHeapAvailable (DWORD Size)
	Checks if the size of the free heap is bigger than the provided size. More...

INTSTATUS	IntLixTaskSendExceptionEvent (DWORD Signal, LIX_TASK_OBJECT *Task)
	Sends an event that contains the information about signal received by the provided task. This function sends the event only if the guest options has the INTRO_OPT_EVENT_PROCESS_CRASH flag. More...

INTSTATUS	IntLixCrashHandle (void *Detour)
	Sends an event that contains the information about signal received by the current task. This function overwrite the return value of the 'complete_signal' with SIGKILL if the current task must be killed; the current task must be killed if an exploit has been detected by the introspection engine. More...

void	IntLixCrashDumpDmesg (void)
	Dumps the 'dmesg' buffer from guest. More...

INTSTATUS	IntLixCrashPanicHandler (void *Detour)
	Called if the 'panic' or 'kcrash_exec' handler is hit. More...

Macro Definition Documentation

◆ LIX_SIGNAL_FATAL

#define LIX_SIGNAL_FATAL ( sig ) !((sig) > 0 && (sig) < SIGRTMIN && (BIT(sig) & (LIX_SIGNAL_IGNORE_MASK | LIX_SIGNAL_STOP_MASK)))

Check if the provided signal is fatal.

The possible effects an unblocked signal set to SIG_DFL can have are:

ignore - Nothing Happens.
terminate - kill the process, i.e. all threads in the group.
coredump - write a core dump file describing all threads using the same mm and then kill all those threads.
stop - stop all the threads in the group, i.e. TASK_STOPPED state

NOTE: For more information see include/linux/signal.h (linux kernel).

Definition at line 45 of file lixcrash.c.

Referenced by IntLixTaskSendExceptionEvent().

◆ LIX_SIGNAL_IGNORE_MASK

#define LIX_SIGNAL_IGNORE_MASK

Value:

(\
        BIT(SIGCONT)   |  BIT(SIGCHLD)   | \
        BIT(SIGWINCH)  |  BIT(SIGURG)    )

The signal for IGNORE action.

Definition at line 30 of file lixcrash.c.

◆ LIX_SIGNAL_STOP_MASK

#define LIX_SIGNAL_STOP_MASK

Value:

(              \
        BIT(SIGSTOP)   |  BIT(SIGTSTP)   |  \
        BIT(SIGTTIN)   |  BIT(SIGTTOU)      )

The signal for STOP action.

Definition at line 23 of file lixcrash.c.

◆ LOG_LINE_MAX

#define LOG_LINE_MAX (1024 - PREFIX_MAX)

Definition at line 17 of file lixcrash.c.

Referenced by IntLixCrashDumpDmesg().

◆ MAX_FUNC_NAME

#define MAX_FUNC_NAME 128

Definition at line 13 of file lixcrash.c.

◆ MAX_LOG_SIZE

#define MAX_LOG_SIZE 512

Definition at line 14 of file lixcrash.c.

◆ MAX_STACKTRACES

#define MAX_STACKTRACES 16

Definition at line 12 of file lixcrash.c.

◆ PREFIX_MAX

#define PREFIX_MAX 32

Definition at line 16 of file lixcrash.c.

Typedef Documentation

◆ PPRINTK_LOG_HEADER

typedef struct _PRINTK_LOG_HEADER * PPRINTK_LOG_HEADER

◆ PRINTK_LOG_HEADER

typedef struct _PRINTK_LOG_HEADER PRINTK_LOG_HEADER

Linux 'struct printk_log' buffer header.

Function Documentation

◆ IntLixCrashDumpDmesg()

void IntLixCrashDumpDmesg ( void )

Dumps the 'dmesg' buffer from guest.

This function search for the 'log_buf', 'log_buf_len' and 'first_idx' and parse the buffer. For Linux kernel 2.6 the 'dmesg' is a continuously buffer of chars. For kernel versions bigger than 2.6 the 'dmesg' has a header 'printk_log' for each line.

Definition at line 340 of file lixcrash.c.

Referenced by IntLixCrashPanicHandler().

◆ IntLixCrashEnoughHeapAvailable()

static BOOLEAN IntLixCrashEnoughHeapAvailable ( DWORD Size )

static

Checks if the size of the free heap is bigger than the provided size.

Parameters

[in] Size The size needed to map the 'dmesg' buffer

Return values

INT_STATUS_SUCCESS True if there's enough heap to map the 'dmesg' buffer, otherwise false

Definition at line 215 of file lixcrash.c.

Referenced by IntLixCrashDumpDmesg().

◆ IntLixCrashFetchDmesgSymbol()

static INTSTATUS IntLixCrashFetchDmesgSymbol	(	QWORD *	LogBufferGva,
		QWORD *	LogBufferLengthGva,
		QWORD *	LogFirstIdxGva
	)

static

Find the address of the symbols 'log_buf', 'log_buf_len' and 'log_first_idx'.

This function tries to search the using IntKsymFindByName; this search may fail because on Debian the symbol is not exported. If the symbol is not exported, the 'log_buf_kexec_setup' function is used to find these symbols. This function initialize the 'log_buf', 'log_len', 'log_first_idx' calling the VMCOREINFO_SYMBOL; knowing these we search for the first three MOV instructions that have the format MOV RDX, immediate and read the immediate value.

Parameters

[out]	LogBufferGva	Contains, on success, the address of 'log_buf'.
[out]	LogBufferLengthGva	Contains, on success, the address of 'log_buf_len'.
[out]	LogFirstIdxGva	Contains, on success, the address of 'log_first_idx'.

Return values

INT_STATUS_SUCCESS	On success.
INT_STATUS_NOT_FOUND	If at symbols is not found.

Definition at line 93 of file lixcrash.c.

Referenced by IntLixCrashDumpDmesg().

◆ IntLixCrashHandle()

INTSTATUS IntLixCrashHandle ( void * Detour )

Sends an event that contains the information about signal received by the current task. This function overwrite the return value of the 'complete_signal' with SIGKILL if the current task must be killed; the current task must be killed if an exploit has been detected by the introspection engine.

Parameters

[in] Detour The internal detour structure.

Return values

INT_STATUS_SUCCESS On success.

Definition at line 298 of file lixcrash.c.

◆ IntLixCrashPanicHandler()

INTSTATUS IntLixCrashPanicHandler ( void * Detour )

Called if the 'panic' or 'kcrash_exec' handler is hit.

This function dumps the 'dmesg' buffer and send an crash event; also set the disable and the bugcheck vars to true in order to uninit the introspection.

Parameters

[in] Detour The internal detour structure.

Return values

INT_STATUS_DISABLE_DETOUR_ON_RET The detours must be removed/disabled because the guest crashed.

Definition at line 493 of file lixcrash.c.

◆ IntLixCrashSendPanicEvent()

static INTSTATUS IntLixCrashSendPanicEvent ( void )

static

Send an event, if the operating system crashed, that contains information about the task that generated the crash.

Return values

INT_STATUS_SUCCESS On success.

Definition at line 65 of file lixcrash.c.

Referenced by IntLixCrashPanicHandler().

◆ IntLixTaskSendExceptionEvent()

INTSTATUS IntLixTaskSendExceptionEvent	(	DWORD	Signal,
		LIX_TASK_OBJECT *	Task
	)

Sends an event that contains the information about signal received by the provided task. This function sends the event only if the guest options has the INTRO_OPT_EVENT_PROCESS_CRASH flag.

Parameters

[in]	Signal	The signal number sent to the task.
[in]	Task	The task that received the signal.

Return values

INT_STATUS_SUCCESS	On success.
INT_STATUS_NOT_NEEDED_HINT	If the INTRO_OPT_EVENT_PROCESS_CRASH flag is not set.

Definition at line 240 of file lixcrash.c.

Referenced by IntLixCrashHandle(), and IntLixTaskDestroy().

Data Structures

Macros

Typedefs

Functions

Macro Definition Documentation

◆ LIX_SIGNAL_FATAL

◆ LIX_SIGNAL_IGNORE_MASK

◆ LIX_SIGNAL_STOP_MASK

◆ LOG_LINE_MAX

◆ MAX_FUNC_NAME

◆ MAX_LOG_SIZE

◆ MAX_STACKTRACES

◆ PREFIX_MAX

Typedef Documentation

◆ PPRINTK_LOG_HEADER

◆ PRINTK_LOG_HEADER

Function Documentation

◆ IntLixCrashDumpDmesg()

◆ IntLixCrashEnoughHeapAvailable()

◆ IntLixCrashFetchDmesgSymbol()

◆ IntLixCrashHandle()

◆ IntLixCrashPanicHandler()

◆ IntLixCrashSendPanicEvent()

◆ IntLixTaskSendExceptionEvent()