iOS Kernel Heap Armageddon - Hakim
iOS Kernel Heap Armageddon - Hakim iOS Kernel Heap Armageddon - Hakim
and kernel_memory_allocate ??? Stefan Esser • iOS Kernel Heap Armageddon REVISITED • July 2012 • 30
kernel_memory_allocate • “master entry point for allocating kernel memory“ • allocates memory in a specific map • allocates always whole pages • requests for more than 1 GB fail immediately • keeps a bunch of heap meta data inside a separate kernel zone • no inbound meta data Stefan Esser • iOS Kernel Heap Armageddon REVISITED • July 2012 • 31
- Page 1 and 2: http://www.sektioneins.de iOS Kerne
- Page 3 and 4: DISCLAIMER iOS 6 • is in beta =>
- Page 5 and 6: So what is this talk about? • zon
- Page 7 and 8: Some Kernel Zones $ zprint kalloc e
- Page 9 and 10: iOS Kernel Zone Allocator 101 • k
- Page 11 and 12: iOS Kernel Zone Allocator 101 • z
- Page 13 and 14: iOS Kernel Zone Allocator 101 • w
- Page 15 and 16: Exploiting the freelist in iOS 6
- Page 17 and 18: Overview Managers and Wrappers not
- Page 19 and 20: kalloc() • kalloc() is a wrapper
- Page 21 and 22: kfree() • kfree() is a bit specia
- Page 23 and 24: _MALLOC() • _MALLOC() is a wrappe
- Page 25 and 26: _MALLOC() in iOS 5.x void *_MALLOC(
- Page 27 and 28: What about kern_os_malloc(), new an
- Page 29: mcache / slab could and might fill
- Page 33 and 34: Cross Zone Attacks • what is the
- Page 35 and 36: Visualization of Zone Page Allocati
- Page 37 and 38: Visualization of Zone Page Allocati
- Page 39 and 40: Visualization of Zone Page Allocati
- Page 41 and 42: Visualization of Zone Page Allocati
- Page 43 and 44: Visualization of Zone Page Allocati
- Page 45 and 46: Visualization of Zone Page Allocati
- Page 47 and 48: Visualization of Zone Page Allocati
- Page 49 and 50: Visualization of Zone Page Allocati
- Page 51 and 52: Visualization of Zone Page Allocati
- Page 53 and 54: Visualization of Zone Page Allocati
- Page 55 and 56: Visualization of Zone Page Allocati
- Page 57 and 58: Visualization of Zone Page Allocati
- Page 59 and 60: Visualization of Zone Page Allocati
- Page 61 and 62: Zone Page Allocation Distribution (
- Page 63 and 64: Cross Memory Allocator Attacks •
- Page 65 and 66: iOS Kernel C++ • iOS kernel‘s l
- Page 67 and 68: OSObject Memory Layout 0x00 0x04 vt
- Page 69 and 70: Overwriting an OSObject in Memory
- Page 71 and 72: OSArray Memory Layout and Overwriti
- Page 73 and 74: “Generic“ Technique to control
- Page 75 and 76: Heap Feng Shui / Heap Massage / ...
- Page 77 and 78: OSUnserializeXML() • deserializat
- Page 79 and 80: How does the parser work? (II) •
kernel_memory_allocate<br />
• “master entry point for allocating kernel memory“<br />
• allocates memory in a specific map<br />
• allocates always whole pages<br />
• requests for more than 1 GB fail immediately<br />
• keeps a bunch of heap meta data inside a separate kernel zone<br />
• no inbound meta data<br />
Stefan Esser • <strong>iOS</strong> <strong>Kernel</strong> <strong>Heap</strong> <strong>Armageddon</strong> REVISITED • July 2012 •<br />
31
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