[release/7.0] Make DacValidateMD more resilient to invalid MethodDesc #79862
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
![github-actions[bot]](https://avatars.githubusercontent.com/in/15368?s=60&v=4){kind=small}
The DacValidateMD is not resilient to invalid MethodDesc that contains NULL in its m_pMethTab field. It was found when using the ClrMD in the BenchmarkDotNet disassembler code which is trying to find if some constants in the code represent MethodDesc so that it can dump the related method name. This change fixes it by checking the MethodTable after it is extracted from the MethodDesc. There are two values that are not translated between the target and the debugger sides - NULL and -1. So I have added handling both as invalid there.
|
Tagging subscribers to this area: @tommcdon Issue DetailsBackport of #79846 to release/7.0 /cc @janvorli Customer ImpactTestingRiskIMPORTANT: Is this backport for a servicing release? If so and this change touches code that ships in a NuGet package, please make certain that you have added any necessary package authoring and gotten it explicitly reviewed.
|
mikem8361
approved these changes
Dec 20, 2022
hoyosjs
approved these changes
Dec 21, 2022
jeffschwMSFT
approved these changes
Jan 3, 2023
rbhanda
added
Servicing-approved
|
Approved by Tactics (7.0.3). |
ghost
locked as resolved and limited conversation to collaborators
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Backport of #79846 to release/7.0
/cc @janvorli
Customer Impact
BenchmarkDotNet crashes when attempting to translate addresses to methods in its disassembly feature
Testing
BenchmarkDotNet tests
Risk
Very low, it just explicitly detects NULL
MethodTableinMethodDescas invalid. Without this detection, theDacValidateMDwhen passed an invalidMethodDescwith NULLMethodTablejust crashes the process with AV. This change is in DAC only.