commit f3751efb5c8b53b37efbbf75d9422c1d11c01646
author Gregory P. Smith <greg@krypto.org> Sat Oct 12 13:24:56 2019 -0700
committer GitHub <noreply@github.com> Sat Oct 12 13:24:56 2019 -0700
tree 2e650d45ee4a530df31c2b66d9457d11e6996f33
parent 8177404d520e81f16324a900f093adf3856d33f8

bpo-38417: Add umask support to subprocess (GH-16726)

On POSIX systems, allow the umask to be set in the child process before we exec.

Modules/_posixsubprocess.c

diff --git a/Modules/_posixsubprocess.c b/Modules/_posixsubprocess.c
index 66db93e..80bb44d 100644
--- a/Modules/_posixsubprocess.c
+++ b/Modules/_posixsubprocess.c
@@ -8,7 +8,7 @@
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
-#if defined(HAVE_SYS_STAT_H) && defined(__FreeBSD__)
+#if defined(HAVE_SYS_STAT_H)
 #include <sys/stat.h>
 #endif
 #ifdef HAVE_SYS_SYSCALL_H
@@ -428,7 +428,7 @@
            int call_setsid,
            int call_setgid, gid_t gid,
            int call_setgroups, size_t groups_size, const gid_t *groups,
-           int call_setuid, uid_t uid,
+           int call_setuid, uid_t uid, int child_umask,
            PyObject *py_fds_to_keep,
            PyObject *preexec_fn,
            PyObject *preexec_fn_args_tuple)
@@ -498,6 +498,9 @@
     if (cwd)
         POSIX_CALL(chdir(cwd));
 
+    if (child_umask >= 0)
+        umask(child_umask);  /* umask() always succeeds. */
+
     if (restore_signals)
         _Py_RestoreSignals();
 
@@ -609,6 +612,7 @@
     int call_setgid = 0, call_setgroups = 0, call_setuid = 0;
     uid_t uid;
     gid_t gid, *groups = NULL;
+    int child_umask;
     PyObject *cwd_obj, *cwd_obj2;
     const char *cwd;
     pid_t pid;
@@ -619,14 +623,14 @@
     int saved_errno = 0;
 
     if (!PyArg_ParseTuple(
-            args, "OOpO!OOiiiiiiiiiiOOOO:fork_exec",
+            args, "OOpO!OOiiiiiiiiiiOOOiO:fork_exec",
             &process_args, &executable_list,
             &close_fds, &PyTuple_Type, &py_fds_to_keep,
             &cwd_obj, &env_list,
             &p2cread, &p2cwrite, &c2pread, &c2pwrite,
             &errread, &errwrite, &errpipe_read, &errpipe_write,
             &restore_signals, &call_setsid,
-            &gid_object, &groups_list, &uid_object,
+            &gid_object, &groups_list, &uid_object, &child_umask,
             &preexec_fn))
         return NULL;
 
@@ -843,7 +847,7 @@
                    errread, errwrite, errpipe_read, errpipe_write,
                    close_fds, restore_signals, call_setsid,
                    call_setgid, gid, call_setgroups, num_groups, groups,
-                   call_setuid, uid,
+                   call_setuid, uid, child_umask,
                    py_fds_to_keep, preexec_fn, preexec_fn_args_tuple);
         _exit(255);
         return NULL;  /* Dead code to avoid a potential compiler warning. */