Kernel/linux-next
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git synced 2024-12-29 09:12:07 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

execve reverts for v6.0-rc7

Browse Source 
- Remove the recent "unshare time namespace on vfork+exec" feature (Andrei Vagin)
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmMoxpIWHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJpd/D/9V7iLUZoquMvXFonv//sRH21P+
 u7vH03q0X4lSov73jdjizq8znZl9RVO14IYi+6lQE8VHyOjzjBoTALRPnirNCyGa
 Ia8P+LPaOHDTDQmGqt+9xmPKp3z0qwrpWWyTrFHLo7GRzWtI0QjQsSlgUTIz7jCw
 dSwLRWN6n7d3hzNzFWt9VUOOlzpip8NTcnAbC9YA5dPFLO85+wZ4ZpMYYfFJMcQj
 N/Zm63lrqAU0wy7EhonkKJQDjgRP/zYUs6VJMejHqYl951SrZJ+DgXEGaAwR14Sz
 IZAUhSM5Fl8alhkrcmlkiy9A5P014iVRR6AaSyeT2616fac97wY1EWHxvBMqzNsB
 AJJqjPHoN+mc8cqt9lMyIhbmS8WkTuyTHziEcFyyTVsNYGYN6x9hVVZalqPrl8o3
 Y3zC6MfRK33JNVB2GZVUzsf5EZC3mjz9VJKKmLwYmG4X7/JOvIVCiW123b060T7z
 b49PzI+0rTG8SHTk1I/T8NpWuvLRTCglzZK06q971uyT80xPoGD/HmSpmm+86dHs
 k3WV2qBoz31Eaoewa3NJqn6pBxQLy9WAZP6rJb3aQSFwDRCuvKO4CUpHAXILt5U+
 SoarR5445zVzY3NYHaf/3BRsEnCQS06U67ma0lAmMWk4J3ehFOY0DrRqtLJ02iwd
 sKJD/KnKC+IEcLjrAA==
 =yFGx
 -----END PGP SIGNATURE-----

Merge tag 'execve-v6.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull execve reverts from Kees Cook:
 "The recent work to support time namespace unsharing turns out to have
  some undesirable corner cases, so rather than allowing the API to stay
  exposed for another release, it'd be best to remove it ASAP, with the
  replacement getting another cycle of testing. Nothing is known to use
  this yet, so no userspace breakage is expected.

  For more details, see:

    https://lore.kernel.org/lkml/ed418e43ad28b8688cfea2b7c90fce1c@ispras.ru

  Summary:

   - Remove the recent 'unshare time namespace on vfork+exec' feature
     (Andrei Vagin)"

* tag 'execve-v6.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  Revert "fs/exec: allow to unshare a time namespace on vfork+exec"
  Revert "selftests/timens: add a test for vfork+exit"
This commit is contained in:
Linus Torvalds 2022-09-20 08:38:55 -07:00
commit f489921dba
5 changed files with 3 additions and 104 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
fs/exec.c
View File

@ -65,7 +65,6 @@
#include <linux/io_uring.h>
#include <linux/syscall_user_dispatch.h>
#include <linux/coredump.h>
#include <linux/time_namespace.h>
#include <linux/uaccess.h>
#include <asm/mmu_context.h>
@ -979,12 +978,10 @@ static int exec_mmap(struct mm_struct *mm)
{
struct task_struct *tsk;
struct mm_struct *old_mm, *active_mm;
bool vfork;
int ret;
/* Notify parent that we're no longer interested in the old VM */
tsk = current;
vfork = !!tsk->vfork_done;
old_mm = current->mm;
exec_mm_release(tsk, old_mm);
if (old_mm)
@ -1029,10 +1026,6 @@ static int exec_mmap(struct mm_struct *mm)
tsk->mm->vmacache_seqnum = 0;
vmacache_flush(tsk);
task_unlock(tsk);
if (vfork)
timens_on_fork(tsk->nsproxy, tsk);
if (old_mm) {
mmap_read_unlock(old_mm);
BUG_ON(active_mm != old_mm);

5
kernel/fork.c
View File

@ -2047,11 +2047,8 @@ static __latent_entropy struct task_struct *copy_process(
/*
* If the new process will be in a different time namespace
* do not allow it to share VM or a thread group with the forking task.
*
* On vfork, the child process enters the target time namespace only
* after exec.
*/
if ((clone_flags & (CLONE_VM | CLONE_VFORK)) == CLONE_VM) {
if (clone_flags & (CLONE_THREAD | CLONE_VM)) {
if (nsp->time_ns != nsp->time_ns_for_children)
return ERR_PTR(-EINVAL);
}

3
kernel/nsproxy.c
View File

@ -179,8 +179,7 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk)
if (IS_ERR(new_ns))
return PTR_ERR(new_ns);
if ((flags & CLONE_VM) == 0)
timens_on_fork(new_ns, tsk);
timens_on_fork(new_ns, tsk);
tsk->nsproxy = new_ns;
return 0;

2
tools/testing/selftests/timens/Makefile
View File

@ -1,4 +1,4 @@
TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs exec futex vfork_exec
TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs exec futex
TEST_GEN_PROGS_EXTENDED := gettime_perf
CFLAGS := -Wall -Werror -pthread

90
tools/testing/selftests/timens/vfork_exec.c
View File

@ -1,90 +0,0 @@
// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <sched.h>
#include <stdio.h>
#include <stdbool.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
#include <string.h>
#include "log.h"
#include "timens.h"
#define OFFSET (36000)
int main(int argc, char *argv[])
{
struct timespec now, tst;
int status, i;
pid_t pid;
if (argc > 1) {
if (sscanf(argv[1], "%ld", &now.tv_sec) != 1)
return pr_perror("sscanf");
for (i = 0; i < 2; i++) {
_gettime(CLOCK_MONOTONIC, &tst, i);
if (abs(tst.tv_sec - now.tv_sec) > 5)
return pr_fail("%ld %ld\n", now.tv_sec, tst.tv_sec);
}
return 0;
}
nscheck();
ksft_set_plan(1);
clock_gettime(CLOCK_MONOTONIC, &now);
if (unshare_timens())
return 1;
if (_settime(CLOCK_MONOTONIC, OFFSET))
return 1;
for (i = 0; i < 2; i++) {
_gettime(CLOCK_MONOTONIC, &tst, i);
if (abs(tst.tv_sec - now.tv_sec) > 5)
return pr_fail("%ld %ld\n",
now.tv_sec, tst.tv_sec);
}
pid = vfork();
if (pid < 0)
return pr_perror("fork");
if (pid == 0) {
char now_str[64];
char *cargv[] = {"exec", now_str, NULL};
char *cenv[] = {NULL};
// Check that we are still in the source timens.
for (i = 0; i < 2; i++) {
_gettime(CLOCK_MONOTONIC, &tst, i);
if (abs(tst.tv_sec - now.tv_sec) > 5)
return pr_fail("%ld %ld\n",
now.tv_sec, tst.tv_sec);
}
/* Check for proper vvar offsets after execve. */
snprintf(now_str, sizeof(now_str), "%ld", now.tv_sec + OFFSET);
execve("/proc/self/exe", cargv, cenv);
return pr_perror("execve");
}
if (waitpid(pid, &status, 0) != pid)
return pr_perror("waitpid");
if (status)
ksft_exit_fail();
ksft_test_result_pass("exec\n");
ksft_exit_pass();
return 0;
}