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-rw-r--r--fs/exec.c15
-rw-r--r--kernel/fork.c5
-rw-r--r--kernel/nsproxy.c3
-rw-r--r--tools/testing/selftests/timens/Makefile2
-rw-r--r--tools/testing/selftests/timens/vfork_exec.c90
5 files changed, 106 insertions, 9 deletions
diff --git a/fs/exec.c b/fs/exec.c
index 778123259e42..5fd73915c62c 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -65,6 +65,7 @@
#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>
@@ -630,7 +631,6 @@ int copy_string_kernel(const char *arg, struct linux_binprm *bprm)
unsigned int bytes_to_copy = min_t(unsigned int, len,
min_not_zero(offset_in_page(pos), PAGE_SIZE));
struct page *page;
- char *kaddr;
pos -= bytes_to_copy;
arg -= bytes_to_copy;
@@ -639,11 +639,8 @@ int copy_string_kernel(const char *arg, struct linux_binprm *bprm)
page = get_arg_page(bprm, pos, 1);
if (!page)
return -E2BIG;
- kaddr = kmap_atomic(page);
flush_arg_page(bprm, pos & PAGE_MASK, page);
- memcpy(kaddr + offset_in_page(pos), arg, bytes_to_copy);
- flush_dcache_page(page);
- kunmap_atomic(kaddr);
+ memcpy_to_page(page, offset_in_page(pos), arg, bytes_to_copy);
put_arg_page(page);
}
@@ -982,10 +979,12 @@ 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)
@@ -1030,6 +1029,10 @@ 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);
@@ -1149,7 +1152,7 @@ static int de_thread(struct task_struct *tsk)
/*
* We are going to release_task()->ptrace_unlink() silently,
* the tracer can sleep in do_wait(). EXIT_DEAD guarantees
- * the tracer wont't block again waiting for this thread.
+ * the tracer won't block again waiting for this thread.
*/
if (unlikely(leader->ptrace))
__wake_up_parent(leader, leader->parent);
diff --git a/kernel/fork.c b/kernel/fork.c
index 9d44f2d46c69..9174146f6812 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2033,8 +2033,11 @@ 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_THREAD | CLONE_VM)) {
+ if ((clone_flags & (CLONE_VM | CLONE_VFORK)) == CLONE_VM) {
if (nsp->time_ns != nsp->time_ns_for_children)
return ERR_PTR(-EINVAL);
}
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index eec72ca962e2..b4cbb406bc28 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -179,7 +179,8 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk)
if (IS_ERR(new_ns))
return PTR_ERR(new_ns);
- timens_on_fork(new_ns, tsk);
+ if ((flags & CLONE_VM) == 0)
+ timens_on_fork(new_ns, tsk);
tsk->nsproxy = new_ns;
return 0;
diff --git a/tools/testing/selftests/timens/Makefile b/tools/testing/selftests/timens/Makefile
index 3a5936cc10ab..f0d51d4d2c87 100644
--- a/tools/testing/selftests/timens/Makefile
+++ b/tools/testing/selftests/timens/Makefile
@@ -1,4 +1,4 @@
-TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs exec futex
+TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs exec futex vfork_exec
TEST_GEN_PROGS_EXTENDED := gettime_perf
CFLAGS := -Wall -Werror -pthread
diff --git a/tools/testing/selftests/timens/vfork_exec.c b/tools/testing/selftests/timens/vfork_exec.c
new file mode 100644
index 000000000000..e6ccd900f30a
--- /dev/null
+++ b/tools/testing/selftests/timens/vfork_exec.c
@@ -0,0 +1,90 @@
+// 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;
+}