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zyarer's avatar
zyarer
Seasoned Newcomer
1 month ago

EasyAntiCheat_EOS Repeatedly Triggers BSOD 0x1a (MEMORY_MANAGEMENT)

EasyAntiCheat_EOS Repeatedly Triggers BSOD 0x1a (MEMORY_MANAGEMENT) 

================================================================

Hardware: Lenovo ThinkBook 16p G5 IRX, i7-14650HX, 32GB DDR5-5600, RTX 4060

BIOS: LENOVO P5CN29WW

OS: Windows 11 26200

Driver: EasyAntiCheat_EOS.sys (39MB; both 2026-03-25 and 2026-07-02 builds reproduce)

Game: Apex Legends

 

5 crashes, all identical signature:

BugCheck 0x1a, Arg1=0x61941, Arg3=9

Bucket: 0x1a_61941_PAGE_TABLE_RESERVED_BITS_SET_IMAGE_hardware_ram

FailureHash same across all: {c6e5c6cf-692e-7852-5dc5-b74944540fc0}

 

Crash path (identical in all 5):

EasyAntiCheat_EOS+0x28f27b (interrupted context)

→ Intel PMI (performance interrupt)

→ nt!EtwpProfileInterrupt → nt!RtlpWalkFrameChain

→ nt!RtlpxLookupFunctionTable+0x35f

→ mov rax,[r10] (r10 points to PTE of EAC code page)

→ PTE reserved bits set → nt!MmAccessFault → 0x1a

 

Key: The PTE mapping EAC's own code page repeatedly has reserved bits set,

indicating a defect in EAC's self page-table management.

EAC reinstalled / both old and new builds reproduce /

RAM diagnostics all pass — excludes user-side hardware and install.

 

4 minidump files attached.

2 Comments

  • I can independently reproduce what appears to be the same crash signature on completely different hardware.

    My system:

    ASUS ROG laptop

    Intel 14th Gen Core i9

    NVIDIA RTX 4080 Laptop GPU

    32 GB RAM

    Windows 11 25H2, OS Build 26200.8875

    Game: Apex Legends

    I have captured multiple independent BSODs.

    My WinDbg results match this report extremely closely.

    MEMORY_MANAGEMENT 0x1A

    Arg1:

    0x61941

    Arg3:

    0x9

    Failure bucket:

    0x1a_61941_PAGE_TABLE_RESERVED_BITS_SET_IMAGE_hardware_ram

    Failure hash:

    c6e5c6cf-692e-7852-5dc5-b74944540fc0

    The kernel path in my dumps is also the same:

    EasyAntiCheat_EOS

    HalpPerfInterrupt / performance profiling interrupt

    EtwpProfileInterrupt

    EtwpTraceStackWalk

    RtlWalkFrameChain

    RtlpxLookupFunctionTable

    KiPageFault

    MmAccessFault

    BugCheck 0x1A

    Most importantly, the interrupted Easy Anti-Cheat execution points in two separate dumps are:

    Crash 1:

    EasyAntiCheat_EOS+0x28f278

    Crash 2:

    EasyAntiCheat_EOS+0x28f27b

    The second offset exactly matches the +0x28f27b reported here, while the first differs by only three bytes.

    I also performed an additional register and paging-hierarchy verification against my kernel MEMORY.DMP.

    At the page-fault trap frame, the fault occurs at:

    nt!RtlpxLookupFunctionTable+0x35f

    The faulting instruction is:

    mov rax, qword ptr [r10]

    At that point:

    r10 = FFFFF3F9FCFE7F80

    The memory at r10 contains:

    0000000000200063

    The interrupted Easy Anti-Cheat execution address was:

    EasyAntiCheat_EOS+0x28f278

    Virtual address:

    FFFFF8027CB2F278

    Running the WinDbg command:

    !pte FFFFF8027CB2F278

    produces:

    PXE at FFFFF3F9FCFE7F80

    PPE at FFFFF3F9FCFF0048

    PDE at FFFFF3F9FE009F28

    PTE at FFFFF3FC013E5978

    The PXE contains:

    0000000000200063

    Therefore, on my system:

    r10 equals the PXE address associated with the interrupted EasyAntiCheat_EOS code address.

    The value at r10 also equals the contents of that PXE.

    This independently reproduces the core paging-hierarchy address relationship described in the original report.

    One terminology clarification: in my dump, r10 points specifically to the PXE, or top-level paging-hierarchy entry, associated with the interrupted EAC code address rather than the final leaf PTE.

    I also disassembled this EAC code region and confirmed that the two offsets seen in my separate crashes are adjacent instructions:

    EasyAntiCheat_EOS+0x28f278:

    mov eax, dword ptr [r14]

    EasyAntiCheat_EOS+0x28f27b:

    push rcx

    This occurs across both launch-time and in-game crashes. At least one of my captured dumps occurred while Apex was already running rather than during the protected-game launcher stage.

    Additional testing on my system:

    MemTest86 completed with zero errors.

    WHEA-Logger shows zero hardware-error events.

    Other demanding games remain stable during extended sessions.

    Other games using Easy Anti-Cheat can initialize EAC and run normally.

    Apex and Easy Anti-Cheat have been reinstalled.

    Intel and NVIDIA drivers have been updated.

    The issue has reproduced independently of using Steam versus EA App.

    This appears to be an independent reproduction of the same crash class on a different OEM laptop and different CPU/GPU configuration.

    The additional paging-hierarchy analysis does not by itself prove which component originally corrupted the paging hierarchy. However, it shows that a second independent machine reproduces the same BugCheck signature, failure hash, performance/ETW stack, EAC code region, and direct relationship between the interrupted EAC address and the paging-hierarchy entry being accessed when the fault is detected.

    Given the identical BugCheck parameters, identical failure hash, matching ETW/performance-interrupt stack, matching EasyAntiCheat_EOS instruction region, and the independently reproduced paging-hierarchy relationship, I would appreciate this being escalated to the Apex/EAC engineering team for investigation as a reproducible Easy Anti-Cheat / Windows kernel interaction rather than being treated as an isolated hardware-memory failure.

    I have two original WinDbg analysis logs and an additional register/PXE verification log available. A kernel MEMORY.DMP is also available privately if engineering requires it.

  • zyarer's avatar
    zyarer
    Seasoned Newcomer
    16 days ago

    Thanks for the independent reproduction — this is exactly what the report needed. I ran the same paging verification on my dumps and confirmed the r10 == PXE relationship holds on my machine too (r10 = FFFFF5FAFD7EBF80 = Arg2,matches !pte for my EAC code page). Both machines share the same OS build 26200.8875, so the common factor is clearly the EAC × Win11 25H2 interaction, not hardware.

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