ci: Update aggressive GC settings for Lua 5.5, fix potential use-after-frees#820
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squeek502 merged 4 commits intoluvit:masterfrom Mar 30, 2026
Merged
ci: Update aggressive GC settings for Lua 5.5, fix potential use-after-frees#820squeek502 merged 4 commits intoluvit:masterfrom
squeek502 merged 4 commits intoluvit:masterfrom
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The previous call only switched to the incremental GC, the numbers afterwards are the Lua 5.4-specific way of setting the pause and stepmul.
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Wasn't expecting this to find actual failures 🙃 Looks to be scandir related EDIT: This is actually finding quite a bit. I guess previous Lua versions never really let us tune the GC to be this aggressive (Lua 5.5 allows "producing a non-incremental, stop-the-world collector"). Or we just didn't tune it as aggressively as possible. |
…lled Previously, it was technically possible for the userdata to be garbage collected before the fulfill_req call, leading to a use-after-free.
This assert is not guaranteed to always be correct, e.g. with a maximally aggressive/stop-the-world incremental GC.
…o GC it It was technically possible for the luv_dir_t to be garbage collected, which would lead to the dirent data being unref'ed and that *also* could garbage collected, before one of the luv_push_dirent calls that use the dirent data (i.e. a possible use-after-free). Seems very unlikely in real-world usage, but 100% reproducible with a maximally aggressive/stop-the-world GC.
squeek502
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truemedian
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Mar 30, 2026
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The previous call only switches to the incremental GC in Lua 5.5; the numbers afterwards are the Lua 5.4-specific way of setting the pause and stepmul.