OpenDevicePartnership / OpenDevicePartnership/documentation

Buffer overrun in sample ASL

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Description

Noting this excerpt from the code block under Secure eSPI Read:

Method (_BST) {
    // *snip*
    Name(BUFF, Buffer(32){}) // Create buffer for send/recv data
    // *snip*
    CreateByteField(BUFF,18, CMDD) // In – First byte of command
    CreateDwordField(BUFF,19, BMA1) // In – Averaging Interval
    CreateField(BUFF,144,128,BSTD) // Out – 4 DWord BST data
    // *snip*
}

BUFF is 32 bytes, buf BSTD overflows into bytes 32-33. The comments make it pretty clear that BSTD is intended to be 4 DWORDs, so the length is correct. Is BUFF supposed to be 34 bytes long?

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Research direction

Start with guide_book/src/intro/concepts/ec_services_example/sample-system-implementation.md at the Secure eSPI Read example and inspect the _BST method. Verify the BUFF size against the CreateField offset and length, then update the example so the buffer bounds match the documented four DWORD BSTD output.

Written by the indexing model from the issue text.

Assessment

Domain
documentation
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
45/100

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