src: fix Boyer-Moore array bounds safety #7
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Refs https://chromium-review.googlesource.com/c/chromium/src/+/6703757 The above CL enabled array bounds sanitization for Electron and therefore Node.js, which triggered a crash in parallel/test-buffer-indexof.js. Upon a bit more investigation, some Boyer-Moore related functions function were using biased pointer arithmetic to create array pointers that point outside the actual array bounds. When start_ is large this creates pointers far outside the valid memory range. The sanitizer detects that we're creating and dereferencing pointers outside array boundaries, even though the final memory access happens to land in valid memory. This changes the functions to use bounds-safe array indexing.
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jasnell
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Jul 10, 2025
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Is this code ever used outside of v8? |
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Or at all? |
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It's used by nodejs and Cloudflare workers. |
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@anonrig Thanks. I'll follow up with my questions elsewhere. :-) |
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Refs https://chromium-review.googlesource.com/c/chromium/src/+/6703757
The above CL enabled array bounds sanitization for Electron and therefore Node.js, which triggered a crash in
parallel/test-buffer-indexof.js. Upon a bit more investigation, some Boyer-Moore related functions function were using biased pointer arithmetic to create array pointers that point outside the actual array bounds.When start_ is large this creates pointers far outside the valid memory range. The sanitizer detects that we're creating and dereferencing pointers outside array boundaries, even though the final memory access happens to land in valid memory.
This changes the functions to use bounds-safe array indexing.