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| author | Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> | 2018-08-15 02:59:11 -0400 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2018-08-15 02:59:11 -0400 |
| commit | 00aebabc7139741fadfe877372c733a2160c7dbd (patch) | |
| tree | d0e80727744d997448ab04424669617759220485 | |
| parent | 1f34aece28d143edb94ca202e661364ca394dc8c (diff) | |
| download | cpython-git-00aebabc7139741fadfe877372c733a2160c7dbd.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>
| -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 0000000000..768f5a26c1 --- /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 069cc6b711..3189873a7a 100644 --- a/Parser/parsetok.c +++ b/Parser/parsetok.c @@ -176,7 +176,7 @@ 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) { fprintf(stderr, "no mem for next token\n"); |