Author: Jan Svoboda Date: 2021-03-15T15:13:47+01:00 New Revision: 23cc8ebf59c661ebb988370a0edbcda37b61080a
URL: https://github.com/llvm/llvm-project/commit/23cc8ebf59c661ebb988370a0edbcda37b61080a DIFF: https://github.com/llvm/llvm-project/commit/23cc8ebf59c661ebb988370a0edbcda37b61080a.diff LOG: [clang][lex] Speculative fix for buffer overrun on raw string parse This attempts to fix a (non-deterministic) buffer overrun when parsing raw string literals during modular build. Similar fix to 4e5b5c36f47c9a406ea7f6b4f89fae477693973a. Reviewed By: beccadax Differential Revision: https://reviews.llvm.org/D94950 Added: Modified: clang/lib/Lex/LiteralSupport.cpp Removed: ################################################################################ diff --git a/clang/lib/Lex/LiteralSupport.cpp b/clang/lib/Lex/LiteralSupport.cpp index 6c3cdbdf6492..df98516ee61d 100644 --- a/clang/lib/Lex/LiteralSupport.cpp +++ b/clang/lib/Lex/LiteralSupport.cpp @@ -1628,16 +1628,28 @@ void StringLiteralParser::init(ArrayRef<Token> StringToks){ // Check for raw string if (ThisTokBuf[0] == 'R') { + if (ThisTokBuf[1] != '"') { + // The file may have come from PCH and then changed after loading the + // PCH; Fail gracefully. + return DiagnoseLexingError(StringToks[i].getLocation()); + } ThisTokBuf += 2; // skip R" + // C++11 [lex.string]p2: A `d-char-sequence` shall consist of at most 16 + // characters. + constexpr unsigned MaxRawStrDelimLen = 16; + const char *Prefix = ThisTokBuf; - while (ThisTokBuf[0] != '(') + while (ThisTokBuf - Prefix < MaxRawStrDelimLen && ThisTokBuf[0] != '(') ++ThisTokBuf; + if (ThisTokBuf[0] != '(') + return DiagnoseLexingError(StringToks[i].getLocation()); ++ThisTokBuf; // skip '(' // Remove same number of characters from the end ThisTokEnd -= ThisTokBuf - Prefix; - assert(ThisTokEnd >= ThisTokBuf && "malformed raw string literal"); + if (ThisTokEnd < ThisTokBuf) + return DiagnoseLexingError(StringToks[i].getLocation()); // C++14 [lex.string]p4: A source-file new-line in a raw string literal // results in a new-line in the resulting execution string-literal. _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
