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ModemIsolationResearch » History » Version 13

Denis 'GNUtoo' Carikli, 03/08/2018 01:06 AM

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h1. ModemSharedMemory
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This page documents in more details the architecture of system on a chip and devices that have shared memory between the modem and the processor running Android. Since the modem runs (only) proprietary software, devices that doesn't have any mechanism that prevent the modem from taking control of the processor running Android are a grave concern for users freedom ans security.
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This page focuses on that issue. Some Qualcomm System On a Chip that are affected by this issue also have other issues that aren't mentioned here but in [[Qualcomm_SOCs|the Qualcomm System On a Chip page]].
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Documenting the issue more in depth might allow us to understand if some devices with shared memory between the modem and the processor running Android might be able to be used safely.
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h2. System on a chip
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This lists system on a chip that also Include a modem and have shared memory between the modem and the processor running Android, and the way the modem and the processor running Android are isolated or not.
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|_. Vendor |_. System on a chip |_. Isolation |_. Market share |_. References |
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| Qualcomm | Mobile Station Modem (MSM) Snapdragon 7x30 | Bad:
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* The modem is in charge of loading the bootloader of the processor running Android. Because of that it can temper with that bootloader and take control of the processor running Android.
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* The modem can access the memory of the processor running Android, and can take control of it through that way.
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* The modem has access to the storage of the processor running Android, so it can take control of it through that.
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| ? | "boot process":http://tjworld.net/wiki/Android/HTC/Vision/BootProcess |
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| Qualcomm | Snapdragon S4 | Unknown? | ? |
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*"Boot process":https://forum.xda-developers.com/showthread.php?t=1769411&page=25
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*"The Security of chip fabric page of rpw-pacsec2013-hexagon.pdf":https://web.archive.org/web/20131224103934if_/https://rpw.io/slides/rpw-pacsec2013-hexagon.pdf |
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h2. Devices
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This lists devices that have the modem and the processor running Android in separate chips and use shared memory between them, along with the way the processor running Android is isolated from the modem, or not.
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|_. Vendor |_. Device |_. Isolation |_. References |
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| Samsung | Nexus S | ? | ? |
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| Samsung | Galaxy S | ? | ? |