Avoid heap corruption with NULLs in TVPs (#1450)#1452
Open
bkline wants to merge 1 commit intomkleehammer:masterfrom
Open
Avoid heap corruption with NULLs in TVPs (#1450)#1452bkline wants to merge 1 commit intomkleehammer:masterfrom
bkline wants to merge 1 commit intomkleehammer:masterfrom
Conversation
The `GetParamType()` function calls `SQLDescribeParam()` and caches the type information it gets from the driver in a dynamically allocated array with one slot for each top-level parameter. This should not be done for nested table column "parameters" because: - that corrupts the heap when a TVP has more columns than slots; - it overwrites top-level parameter types with the wrong values; - `SQLDescribeParam()` fails for nested column "parameters" anyway. So for NULL TVP columns we fall back on SQL_VARCHAR. With the fix contained in this commit, the new test never fails (for my testing, at least). Without the fix, that test sometimes passes and sometimes crashes the Python interpreter (and *always* crashed Python when the `tests/__pycache__` directory was not present in my testing--not sure why 🤷♂️). Closes mkleehammer#1450
Collaborator
|
@v-chojas I believe you created the original code to support TVPs, so if you have time to look at this PR, that would be much appreciated. |
This file contains hidden or 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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
The
GetParamType()function callsSQLDescribeParam()and caches the type information it gets from the driver in a dynamically allocated array with one slot for each top-level parameter. This should not be done for nested table column "parameters" because:SQLDescribeParam()fails for nested column "parameters" anyway.So for NULL TVP columns we fall back on SQL_VARCHAR.
With the fix contained in this commit, the new test never fails (for my testing, at least). Without the fix, that test sometimes passes and sometimes crashes the Python interpreter (and always crashed Python when the
tests/__pycache__directory was not present in my testing--not sure why 🤷♂️).Closes #1450