iOS Kernel Heap Armageddon - Hakim
iOS Kernel Heap Armageddon - Hakim iOS Kernel Heap Armageddon - Hakim
Heap Feng Shui / Heap Massage / ... • allocate repeatedly ✔ • allocate arbitrary sized memory blocks ✔ • poke allocation holes in specific positions • control the memory layout • fill memory with interesting meta / application data ✔ Stefan Esser • iOS Kernel Heap Armageddon REVISITED • July 2012 • 94
Poking Holes into Allocated Data • deallocation of arbitrary sized memory is possible with • reusing the same dictionary key will delete the previously inserted value • in this example the middle value ZZZ...ZZZ is freed AAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA BBBB AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA CCCC ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ DDDD AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA EEEE AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA CCCC Stefan Esser • iOS Kernel Heap Armageddon REVISITED • July 2012 • 95
- 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) •
- Page 81 and 82: How does the parser work? (IV) •
- Page 83 and 84: How does the parser work? (VI) •
- Page 85 and 86: How does the parser work? (VIII)
- Page 87 and 88: Heap Spraying (Remember?) • alloc
- Page 89 and 90: Heap Spraying • allocate repeated
- Page 91 and 92: Heap Spraying • allocate repeated
- Page 93: Fill Arbitrary Sized Memory Blocks
- Page 97 and 98: Extra: Keeping Data Allocated • s
<strong>Heap</strong> Feng Shui / <strong>Heap</strong> Massage / ...<br />
• allocate repeatedly ✔<br />
• allocate arbitrary sized memory blocks ✔<br />
• poke allocation holes in specific positions<br />
• control the memory layout<br />
• fill memory with interesting meta / application data ✔<br />
Stefan Esser • <strong>iOS</strong> <strong>Kernel</strong> <strong>Heap</strong> <strong>Armageddon</strong> REVISITED • July 2012 •<br />
94
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