52 lines
2.3 KiB
Diff
52 lines
2.3 KiB
Diff
From be3c3a0e468237430ad7d19a33c60d306199a7f2 Mon Sep 17 00:00:00 2001
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From: "Gregory P. Smith" <greg@krypto.org>
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Date: Sat, 24 Oct 2020 12:07:35 -0700
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Subject: [PATCH] bpo-35823: Allow setsid() after vfork() on Linux. (GH-22945)
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It should just be a syscall updating a couple of fields in the kernel side
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process info. Confirming, in glibc is appears to be a shim for the setsid
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syscall (based on not finding any code implementing anything special for it)
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and in uclibc (*much* easier to read) it is clearly just a setsid syscall shim.
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A breadcrumb _suggesting_ that it is not allowed on Darwin/macOS comes from
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a commit in emacs: https://lists.gnu.org/archive/html/bug-gnu-emacs/2017-04/msg00297.html
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but I don't have a way to verify if that is true or not.
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As we are not supporting vfork on macOS today I just left a note in a comment.
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---
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Modules/_posixsubprocess.c | 5 +++--
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1 file changed, 3 insertions(+), 2 deletions(-)
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diff --git a/Modules/_posixsubprocess.c b/Modules/_posixsubprocess.c
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index b7cba30..8baea31 100644
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--- a/Modules/_posixsubprocess.c
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+++ b/Modules/_posixsubprocess.c
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@@ -38,6 +38,8 @@
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#if defined(__linux__) && defined(HAVE_VFORK) && defined(HAVE_SIGNAL_H) && \
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defined(HAVE_PTHREAD_SIGMASK) && !defined(HAVE_BROKEN_PTHREAD_SIGMASK)
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+/* If this is ever expanded to non-Linux platforms, verify what calls are
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+ * allowed after vfork(). Ex: setsid() may be disallowed on macOS? */
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# include <signal.h>
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# define VFORK_USABLE 1
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#endif
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@@ -712,7 +714,6 @@ struct linux_dirent64 {
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#ifdef VFORK_USABLE
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if (child_sigmask) {
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/* These are checked by our caller; verify them in debug builds. */
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- assert(!call_setsid);
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assert(!call_setuid);
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assert(!call_setgid);
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assert(!call_setgroups);
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@@ -997,7 +998,7 @@ struct linux_dirent64 {
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/* Use vfork() only if it's safe. See the comment above child_exec(). */
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sigset_t old_sigs;
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if (preexec_fn == Py_None &&
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- !call_setuid && !call_setgid && !call_setgroups && !call_setsid) {
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+ !call_setuid && !call_setgid && !call_setgroups) {
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/* Block all signals to ensure that no signal handlers are run in the
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* child process while it shares memory with us. Note that signals
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* used internally by C libraries won't be blocked by
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--
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1.8.3.1
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