diff options
| -rw-r--r-- | fs/exec.c | 15 | ||||
| -rw-r--r-- | kernel/fork.c | 5 | ||||
| -rw-r--r-- | kernel/nsproxy.c | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/timens/Makefile | 2 | ||||
| -rw-r--r-- | tools/testing/selftests/timens/vfork_exec.c | 90 |
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; +} |