[3.10] bpo-41486: zlib uses an UINT32_MAX sliding window for the output buffer (GH-26143) #27025
Conversation
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
…er (pythonGH-26143) * zlib uses an UINT32_MAX sliding window for the output buffer These funtions have an initial output buffer size parameter: - zlib.decompress(data, /, wbits=MAX_WBITS, bufsize=DEF_BUF_SIZE) - zlib.Decompress.flush([length]) If the initial size > UINT32_MAX, use an UINT32_MAX sliding window, instead of clamping to UINT32_MAX. Speed up when (the initial size == the actual size). This fixes a memory consumption and copying performance regression in earlier 3.10 beta releases if someone used an output buffer larger than 4GiB with zlib.decompress. Reviewed-by: Gregory P. Smith (cherry picked from commit a9a69bb) Co-authored-by: Ma Lin <animalize@users.noreply.github.com>
| @animalize and @gpshead: Status check is done, and it's a success ✅ . |
bedevere-bot added type-bug 
gpshead approved these changes Jul 5, 2021
| @animalize and @gpshead: Status check is done, and it's a success ✅ . |
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
4 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 Outdated suggestions cannot be applied.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.
These funtions have an initial output buffer size parameter:
If the initial size > UINT32_MAX, use an UINT32_MAX sliding window, instead of clamping to UINT32_MAX.
Speed up when (the initial size == the actual size).
This fixes a memory consumption and copying performance regression in earlier 3.10 beta releases if someone used an output buffer larger than 4GiB with zlib.decompress.
Reviewed-by: Gregory P. Smith
(cherry picked from commit a9a69bb)
Co-authored-by: Ma Lin animalize@users.noreply.github.com
https://bugs.python.org/issue41486
Automerge-Triggered-By: GH:gpshead