From 746b2d35ea47005054ed774fecaed64fab803d7d Mon Sep 17 00:00:00 2001 From: "Gregory P. Smith" Date: Tue, 13 Nov 2018 13:16:54 -0800 Subject: [PATCH] bpo-35214: Fix OOB memory access in unicode escape parser (GH-10506) Discovered using clang's MemorySanitizer when it ran python3's test_fstring test_misformed_unicode_character_name. An msan build will fail by simply executing: ./python -c 'u"\N"' --- .../Core and Builtins/2018-11-13-00-40-35.bpo-35214.OQBjph.rst | 3 +++ Objects/unicodeobject.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) create mode 100644 Misc/NEWS.d/next/Core and Builtins/2018-11-13-00-40-35.bpo-35214.OQBjph.rst diff --git a/Misc/NEWS.d/next/Core and Builtins/2018-11-13-00-40-35.bpo-35214.OQBjph.rst b/Misc/NEWS.d/next/Core and Builtins/2018-11-13-00-40-35.bpo-35214.OQBjph.rst new file mode 100644 index 0000000000..d462c97d80 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2018-11-13-00-40-35.bpo-35214.OQBjph.rst @@ -0,0 +1,3 @@ +Fixed an out of bounds memory access when parsing a truncated unicode +escape sequence at the end of a string such as ``'\N'``. It would read +one byte beyond the end of the memory allocation. diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c index e5d026f9aa..04ca5f3344 100644 --- a/Objects/unicodeobject.c +++ b/Objects/unicodeobject.c @@ -6069,7 +6069,7 @@ _PyUnicode_DecodeUnicodeEscape(const char *s, } message = "malformed \\N character escape"; - if (*s == '{') { + if (s < end && *s == '{') { const char *start = ++s; size_t namelen; /* look for the closing brace */ -- 2.40.0