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Merge #11284: Fix invalid memory access in CScript::operator+= (guidovranken, ajtowns)
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Authored by jasonbcox on Jun 20 2019, 03:12.

Details

Summary

d601f16 Fix invalid memory access in CScript::operator+= (Anthony Towns)

Pull request description:

This is a fix for #11114 -- invoking "s += s" gets turned into "s.insert(s.end(), s.begin(), s.end())" which can result in an invalid memory access is s.capacity() < 2*s.size() (because s gets resized and possibly moved, so s.begin() and s.end() become invalid references when reading the values to be appended).

The fix is straightforward: reserve enough space in advance, so that insert() doesn't need to resize and thus its arguments remain valid.

A simple test case is added as well; though you probably need to run it via valgrind to actually catch the problem when it's not fixed...

Tree-SHA512: 4720d0c17463fdc43b344c45fe603423d20b30d48da1b9d85eeedc505d7f34db1ed5495ef1556459ae962a94717e3c6e8fc441763771901efea210d01322b7ef

Backport of Core PR11284
https://github.com/bitcoin/bitcoin/pull/11284/files

Test Plan

make check

Diff Detail

Repository
rABC Bitcoin ABC
Branch
pr11284
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Unit
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Build Status
Buildable 6413
Build 10873: Bitcoin ABC Buildbot (legacy)
Build 10872: arc lint + arc unit