Fix defrag issues for pubsub and lua#14330
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Pull Request Overview
This PR fixes defragmentation issues for pubsub and lua functionality that were introduced by a previous change. The fix addresses problems where memory defragmentation could reallocate objects that were still being referenced, leading to potential use-after-free scenarios.
- Moved lua script execution to occur after LRU list manipulation to prevent accessing reallocated memory
- Added a new dictionary lookup function that uses pointer comparison instead of key comparison for defrag scenarios
- Updated pubsub defrag callback to use the new lookup method to handle reallocated channel names
Reviewed Changes
Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.
| File | Description |
|---|---|
| src/eval.c | Reordered lua script execution and LRU operations, added safety comment about memory reallocation |
| src/dict.h | Added declaration for new dictFindByHashAndPtr function |
| src/dict.c | Implemented dictFindByHashAndPtr function for pointer-based dictionary lookups |
| src/defrag.c | Updated pubsub defrag callback to use hash and pointer lookup instead of key-based lookup |
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oranagra
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This PR fixes two defrag issues. 1. Fix a use-after-free issue caused by updating dictionary keys after a pubsub channel is reallocated. This issue was introduced by redis#13058 1. Fix potential use-after-free for lua during AOF loading with defrag This issue was introduced by redis#13058 This fix follows redis#14319 This PR updates the LuaScript LRU list before script execution to prevent accessing a potentially invalidated pointer after long-running scripts.
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This PR fixes two defrag issues. 1. Fix a use-after-free issue caused by updating dictionary keys after a pubsub channel is reallocated. This issue was introduced by redis#13058 1. Fix potential use-after-free for lua during AOF loading with defrag This issue was introduced by redis#13058 This fix follows redis#14319 This PR updates the LuaScript LRU list before script execution to prevent accessing a potentially invalidated pointer after long-running scripts.
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This PR fixes two defrag issues. 1. Fix a use-after-free issue caused by updating dictionary keys after a pubsub channel is reallocated. This issue was introduced by redis#13058 2. Fix potential use-after-free for lua during AOF loading with defrag This issue was introduced by redis#13058 This fix follows redis#14319 This PR updates the LuaScript LRU list before script execution to prevent accessing a potentially invalidated pointer after long-running scripts.
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This PR fixes two defrag issues.
Fix a use-after-free issue caused by updating dictionary keys after a pubsub channel is reallocated.
This issue was introduced by Implement defragmentation for pubsub kvstore #13058
Fix potential use-after-free for lua during AOF loading with defrag
This issue was introduced by Implement defragmentation for pubsub kvstore #13058
This fix follows Fix crash during lua script defrag #14319
This PR updates the LuaScript LRU list before script execution to prevent accessing a potentially invalidated pointer after long-running scripts.
Note that both of these issues were introduced since 7.4, so we can fix them together.