From f668f73bc88cce0112b304d87aa998fb28013c71 Mon Sep 17 00:00:00 2001 From: "Erlend E. Aasland" Date: Fri, 9 Jun 2023 22:07:47 +0200 Subject: gh-105375: Improve posix error handling (#105592) Fix a bug where an IndexError could end up being overwritten. --- .../Library/2023-06-09-21-30-59.gh-issue-105375.eewafp.rst | 2 ++ Modules/posixmodule.c | 12 ++++++++---- 2 files changed, 10 insertions(+), 4 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2023-06-09-21-30-59.gh-issue-105375.eewafp.rst diff --git a/Misc/NEWS.d/next/Library/2023-06-09-21-30-59.gh-issue-105375.eewafp.rst b/Misc/NEWS.d/next/Library/2023-06-09-21-30-59.gh-issue-105375.eewafp.rst new file mode 100644 index 0000000..e000f98 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2023-06-09-21-30-59.gh-issue-105375.eewafp.rst @@ -0,0 +1,2 @@ +Fix a bug in the :mod:`posix` module where an exception could be +overwritten. diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c index 6f01b70..694cff1 100644 --- a/Modules/posixmodule.c +++ b/Modules/posixmodule.c @@ -6414,7 +6414,7 @@ parse_envlist(PyObject* env, Py_ssize_t *envc_ptr) { Py_ssize_t i, pos, envc; PyObject *keys=NULL, *vals=NULL; - PyObject *key, *val, *key2, *val2, *keyval; + PyObject *key2, *val2, *keyval; EXECV_CHAR **envlist; i = PyMapping_Size(env); @@ -6439,10 +6439,14 @@ parse_envlist(PyObject* env, Py_ssize_t *envc_ptr) } for (pos = 0; pos < i; pos++) { - key = PyList_GetItem(keys, pos); - val = PyList_GetItem(vals, pos); - if (!key || !val) + PyObject *key = PyList_GetItem(keys, pos); // Borrowed ref. + if (key == NULL) { goto error; + } + PyObject *val = PyList_GetItem(vals, pos); // Borrowed ref. + if (val == NULL) { + goto error; + } #if defined(HAVE_WEXECV) || defined(HAVE_WSPAWNV) if (!PyUnicode_FSDecoder(key, &key2)) -- cgit v0.12