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| author | Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> | 2018-08-15 02:51:12 -0400 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2018-08-15 02:51:12 -0400 |
| commit | 2275b773ebfacb94f6a9c81d6a8b9d54771a68e8 (patch) | |
| tree | a946c7fd46bfd3477ac312ead8f9384d186c8ed4 /Parser | |
| parent | e3228a3f44e382b6cdd2b5e001b651347013a7d3 (diff) | |
| download | cpython-git-2275b773ebfacb94f6a9c81d6a8b9d54771a68e8.tar.gz | |
closes bpo-34400: Fix undefined behavior in parsetok(). (GH-4439)
Avoid undefined pointer arithmetic with NULL.
(cherry picked from commit 7c4ab2afb17b99eb3f61f9c73cbd548b5e0ad2c0)
Co-authored-by: Zackery Spytz <zspytz@gmail.com>
Diffstat (limited to 'Parser')
| -rw-r--r-- | Parser/parsetok.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/Parser/parsetok.c b/Parser/parsetok.c index 00d741d221..b9c9fe8fa8 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; |