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  • S_x96x_S

    addikt

    ( security, GDDR6 )
    https://gddr.fail/
    nvidia GDDR6, GDDR6X -es rendszereket érintheti,
    és az RTX 3060 , RTX 6000 Ampere - biztos érintett ( mert azokat tesztelték )
    ( ez főleg a datacenteres felhasználóknál lehet probléma. )

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    "GPU Memory Exploits
    The GDDRHammer and GeForge teams independently developed exploits that utilize Rowhammer bit flips on Graphics Processing Units (GPUs) to enable a full takeover of Central Processing Unit (CPU) memory from an unprivileged GPU kernel, enabling an attacker to read and write all of the CPU's memory. In addition, we developed novel Rowhammer techniques for GPUs that result in a dramatic increase in the number of bit flips found on GDDR6 memory."

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    "In this work, we provide a Rowhammer characterization of 25 GDDR6 GPUs, including Ampere and Ada 6000 GPUs. "

    GDDRHammer: Greatly Disturbing DRAM Rows — Cross-Component
    Rowhammer Attacks from Modern GPUs :
    https://gddr.fail/files/gddrhammer.pdf
    "Abstract—While Rowhammer has been extensively studied in
    CPU-based memory systems, a very recent work by Lin et
    al. (USENIX Security ‘25) extended this line of research to
    GDDR6 GPU memory, demonstrating the first Rowhammer bit
    flips on NVIDIA GPUs. However, they tested only a single GPU
    and observed just 8 flips across 4 DRAM banks. Moreover,
    their proof-of-concept exploit only demonstrated degradation
    of a deep neural network’s inference, leaving both the extent
    of GPUs’ susceptibility to Rowhammer and the impact of said
    bit flips largely unexplored.
    We address this gap by exploring both the prevalence and
    impact of Rowhammer on GPUs. First, we develop techniques
    for dramatically amplifying Rowhammer on modern GDDR6-
    based GPUs. By utilizing the inherent parallelism in GPUs
    and developing new techniques for bypassing Rowhammer
    mitigations on GPUs, we are able to produce 129 bit flips per
    DRAM bank on average, demonstrating a 64x increase over
    prior work. We also present a comprehensive characterization
    of GPUs’ Rowhammer susceptibility by testing more than 25
    GPUs across multiple systems. Our findings show that nearly
    all tested RTX A6000 GPUs remain vulnerable under realistic
    configurations despite hardware-level mitigations, demonstrat-
    ing that Rowhammer is far more prevalent on GDDR6 memory
    than previously understood.
    We also show the impact of Rowhammer on GPUs by
    demonstrating the first GPU-to-CPU Rowhammer exploit, with
    a practical end-to-end attack wherein an attacker flips bits in
    the GPU’s memory and gains read and write access to all of
    the host CPU’s memory."

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    GeForge: Hammering GDDR Memory to Forge GPU Page Tables for Fun and Profit
    https://gddr.fail/files/GeForge.pdf
    "Abstract—Over the years, Rowhammer has been leveraged to
    mount a wide range of attacks against system main memory.
    While a recent study has revealed that GPU memory is
    similarly vulnerable, the security implications remain largely
    under-explored. To advance this line of research, we introduce
    GeForge, an end-to-end Rowhammer attack that exploits
    bit flips induced in GPU memory to achieve system-level
    compromise. At its core, GeForge corrupts GPU page tables to
    seize control of address translation, enabling arbitrary access
    to the entire GPU memory. Moreover, by exploiting a special
    mapping feature in the GPU page table, GeForge extends its
    reach to directly access host memory.
    To make GeForge practical under default system settings,
    we develop novel techniques that eliminate restrictive assump-
    tions in prior work. Our techniques include a method for
    aligning offline-profiled physical address mappings to runtime
    GPU allocations and a memory massaging strategy that steers
    target GPU page table structures into vulnerable locations via
    the stock driver allocator. In addition, we improve the hammer-
    ing pattern to trigger many more bit flips than prior work.
    With these approaches, we successfully mount GeForge on
    widely deployed NVIDIA GPUs, including both workstation-
    class and consumer-grade ones. We show that GeForge allows
    an attacker to arbitrarily read and modify data across GPU
    contexts. More crucially, we demonstrate that GeForge can
    help the attacker escalate privileges to root on the host system."

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    újságirós értelmezés:
    https://arstechnica.com/security/2026/04/new-rowhammer-attacks-give-complete-control-of-machines-running-nvidia-gpus/
    New Rowhammer attacks give complete control of machines running Nvidia GPUs
    Both GDDRHammer and GeForge hammer GPU memory in ways that compromise the CPU

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