3 ms·
No. The baseband can DMA what it wants, when it wants. The baseband PMIC can power what it wants when wants. The AP is the junior partner.
by pdoege 4y ago
No. The baseband can DMA what it wants, when it wants. The baseband PMIC can power what it wants when wants. The AP is the junior partner.
- flangola7 4y agoIOUMMU prevents this
- userbinator 4y agoNot on MTK chipsets, or at least the older ones I'm familiar with: https://github.com/varunchitre15/MT6589_kernel_source/blob/master/mediatek/platform/mt6589/kernel/drivers/dual_ccci/src/ccci_platform.c https://github.com/varunchitre15/MT6589_kernel_source/blob/m... Look at the enable_mem_access_protection function.
- notactuallyben 4y agoThis is not true on pretty much any phone post 2014ish. Pretty much all platforms have IOMMU's or similar separation mechanisms. source: did baseband vr commercially
- Analemma_ 4y agoBasebands have not had DMA for a long time. There can still be vulnerabilities, which it sounds like is what happened here, but there’s no DMA anymore on new phones.
- p_l 4y agoThat was (possibly still is) the case on Qualcomm integrated Application and Baseband SoCs, not on Exynos where baseband is the junior partner.