UefiHandler: fix off-by-one OOB read in ParseDepedencyExpression (backport 7-Zip 26.01) - #259
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ParseDepedencyExpression validates the dependency-expression opcode with > instead of >=, allowing command == ARRAY_SIZE(kExpressionCommands) to pass and then dereference kExpressionCommands[command], which is one element past the end of the static const array. The OOB load is then passed to AString::operator+=(const char *) via strlen on whatever bytes follow the array in the binary, potentially leaking adjacent .rodata content or crashing on unmapped memory. The upstream 7-Zip 26.01 release tightened this check from > to >=. Signed-off-by: tonghuaroot <tonghuaroot@gmail.com>
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Backports a one-line off-by-one fix landed silently in upstream 7-Zip 26.01.
Bug
ParseDepedencyExpressionatCPP/7zip/Archive/UefiHandler.cpp:399:The bound uses
>instead of>=. Whencommand == ARRAY_SIZE(kExpressionCommands), the check passes and the next line readskExpressionCommands[command], which is one element past the end of the static const array. The result then feedsAString::operator+= (const char *), which callsstrlenon whatever bytes follow the array in.rodata. Depending on the build, this leaks adjacent constant data or hits unmapped memory and crashes the extractor.Fix
Tighten the bound to
>=, matching the upstream 26.01 source:(Replaces the previously-closed PR #255 which had a polluted base.)