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| author | Zackery Spytz <zspytz@gmail.com> | 2018-08-15 06:27:26 (GMT) |
|---|---|---|
| committer | Benjamin Peterson <benjamin@python.org> | 2018-08-15 06:27:26 (GMT) |
| commit | 7c4ab2afb17b99eb3f61f9c73cbd548b5e0ad2c0 (patch) | |
| tree | a336b89b5a916bf8bdf2ce87704e6636637b00ba | |
| parent | 88bfd0bce05043f658e50addd21366f317995e35 (diff) | |
| download | cpython-7c4ab2afb17b99eb3f61f9c73cbd548b5e0ad2c0.zip cpython-7c4ab2afb17b99eb3f61f9c73cbd548b5e0ad2c0.tar.gz cpython-7c4ab2afb17b99eb3f61f9c73cbd548b5e0ad2c0.tar.bz2 | |
closes bpo-34400: Fix undefined behavior in parsetok(). (GH-4439)
Avoid undefined pointer arithmetic with NULL.
| -rw-r--r-- | Misc/NEWS.d/next/Core and Builtins/2018-08-14-03-52-43.bpo-34400.AJD0bz.rst | 1 | ||||
| -rw-r--r-- | Parser/parsetok.c | 2 |
2 files changed, 2 insertions, 1 deletions
diff --git a/Misc/NEWS.d/next/Core and Builtins/2018-08-14-03-52-43.bpo-34400.AJD0bz.rst b/Misc/NEWS.d/next/Core and Builtins/2018-08-14-03-52-43.bpo-34400.AJD0bz.rst new file mode 100644 index 0000000..768f5a2 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2018-08-14-03-52-43.bpo-34400.AJD0bz.rst @@ -0,0 +1 @@ +Fix undefined behavior in parsetok.c. Patch by Zackery Spytz. diff --git a/Parser/parsetok.c b/Parser/parsetok.c index 00d741d..b9c9fe8 100644 --- a/Parser/parsetok.c +++ b/Parser/parsetok.c @@ -225,7 +225,7 @@ parsetok(struct tok_state *tok, grammar *g, int start, perrdetail *err_ret, } else started = 1; - len = b - a; /* XXX this may compute NULL - NULL */ + len = (a != NULL && b != NULL) ? b - a : 0; str = (char *) PyObject_MALLOC(len + 1); if (str == NULL) { err_ret->error = E_NOMEM; |