header_rewrite: Fix a leak and truncation in set-body-from#13303
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moonchen wants to merge 2 commits into
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header_rewrite: Fix a leak and truncation in set-body-from#13303moonchen wants to merge 2 commits into
moonchen wants to merge 2 commits into
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TSUrlStringGet allocates the return value. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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Pull request overview
Fixes a memory leak in the header_rewrite plugin’s set-body-from operator by releasing the TSmalloc()-owned buffer returned by TSUrlStringGet(), aligning ownership handling with existing ConditionUrl logic.
Changes:
- Free the URL string returned by
TSUrlStringGet()increateRequestString()to prevent per-transaction leaks whenset-body-fromrules match.
snprintf() returns the length it would have written, which can exceed the 256-byte request buffer. Passing that length to TSFetchUrl() would read past req_buf, so error out instead of sending a truncated request. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
moonchen
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JosiahWI
approved these changes
Jun 19, 2026
| TSfree(url); | ||
| TSMBufferDestroy(url_buf); | ||
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| if (written < 0 || static_cast<unsigned int>(written) >= MAX_SIZE) { |
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The >= relation is correct, because written does not include the null terminator.
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Two related fixes in the header_rewrite
set-body-fromoperator'screateRequestString():Memory leak. The request URL was fetched with
TSUrlStringGet(), which returns aTSmalloc()-allocated buffer the caller owns, but it was never freed. Every non-internal transaction matching aset-body-fromrule leaked one URL-sized allocation, growing unbounded over time. Free it, mirroring the existing owned-pointer handling inConditionUrl.Truncation / buffer over-read.
snprintf()returns the length it would have written, not the number of bytes actually written, and that value can exceed the 256-bytereq_buf. Passing it toTSFetchUrl()as the request length reads past the stack buffer when a URL overflows. The request has always been capped at 256 bytes —snprintf()only ever writes that much intoreq_buf— so this changes nothing for requests that fit; it just returnsTS_ERRORon overflow instead of over-reading. (Raised by Copilot review.)🤖 Generated with Claude Code