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Diffstat (limited to 'fs/exec.c')
-rw-r--r--fs/exec.c110
1 files changed, 83 insertions, 27 deletions
diff --git a/fs/exec.c b/fs/exec.c
index db17be51b112..2c465119affc 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -985,6 +985,32 @@ int kernel_read_file_from_path(const char *path, void **buf, loff_t *size,
}
EXPORT_SYMBOL_GPL(kernel_read_file_from_path);
+int kernel_read_file_from_path_initns(const char *path, void **buf,
+ loff_t *size, loff_t max_size,
+ enum kernel_read_file_id id)
+{
+ struct file *file;
+ struct path root;
+ int ret;
+
+ if (!path || !*path)
+ return -EINVAL;
+
+ task_lock(&init_task);
+ get_fs_root(init_task.fs, &root);
+ task_unlock(&init_task);
+
+ file = file_open_root(root.dentry, root.mnt, path, O_RDONLY, 0);
+ path_put(&root);
+ if (IS_ERR(file))
+ return PTR_ERR(file);
+
+ ret = kernel_read_file(file, buf, size, max_size, id);
+ fput(file);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns);
+
int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size,
enum kernel_read_file_id id)
{
@@ -1010,16 +1036,26 @@ ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len)
}
EXPORT_SYMBOL(read_code);
+/*
+ * Maps the mm_struct mm into the current task struct.
+ * On success, this function returns with the mutex
+ * exec_update_mutex locked.
+ */
static int exec_mmap(struct mm_struct *mm)
{
struct task_struct *tsk;
struct mm_struct *old_mm, *active_mm;
+ int ret;
/* Notify parent that we're no longer interested in the old VM */
tsk = current;
old_mm = current->mm;
exec_mm_release(tsk, old_mm);
+ ret = mutex_lock_killable(&tsk->signal->exec_update_mutex);
+ if (ret)
+ return ret;
+
if (old_mm) {
sync_mm_rss(old_mm);
/*
@@ -1031,9 +1067,11 @@ static int exec_mmap(struct mm_struct *mm)
down_read(&old_mm->mmap_sem);
if (unlikely(old_mm->core_state)) {
up_read(&old_mm->mmap_sem);
+ mutex_unlock(&tsk->signal->exec_update_mutex);
return -EINTR;
}
}
+
task_lock(tsk);
active_mm = tsk->active_mm;
membarrier_exec_mmap(mm);
@@ -1189,10 +1227,22 @@ no_thread_group:
/* we have changed execution domain */
tsk->exit_signal = SIGCHLD;
-#ifdef CONFIG_POSIX_TIMERS
- exit_itimers(sig);
- flush_itimer_signals();
-#endif
+ BUG_ON(!thread_group_leader(tsk));
+ return 0;
+
+killed:
+ /* protects against exit_notify() and __exit_signal() */
+ read_lock(&tasklist_lock);
+ sig->group_exit_task = NULL;
+ sig->notify_count = 0;
+ read_unlock(&tasklist_lock);
+ return -EAGAIN;
+}
+
+
+static int unshare_sighand(struct task_struct *me)
+{
+ struct sighand_struct *oldsighand = me->sighand;
if (refcount_read(&oldsighand->count) != 1) {
struct sighand_struct *newsighand;
@@ -1210,23 +1260,13 @@ no_thread_group:
write_lock_irq(&tasklist_lock);
spin_lock(&oldsighand->siglock);
- rcu_assign_pointer(tsk->sighand, newsighand);
+ rcu_assign_pointer(me->sighand, newsighand);
spin_unlock(&oldsighand->siglock);
write_unlock_irq(&tasklist_lock);
__cleanup_sighand(oldsighand);
}
-
- BUG_ON(!thread_group_leader(tsk));
return 0;
-
-killed:
- /* protects against exit_notify() and __exit_signal() */
- read_lock(&tasklist_lock);
- sig->group_exit_task = NULL;
- sig->notify_count = 0;
- read_unlock(&tasklist_lock);
- return -EAGAIN;
}
char *__get_task_comm(char *buf, size_t buf_size, struct task_struct *tsk)
@@ -1260,13 +1300,13 @@ void __set_task_comm(struct task_struct *tsk, const char *buf, bool exec)
*/
int flush_old_exec(struct linux_binprm * bprm)
{
+ struct task_struct *me = current;
int retval;
/*
- * Make sure we have a private signal table and that
- * we are unassociated from the previous thread group.
+ * Make this the only thread in the thread group.
*/
- retval = de_thread(current);
+ retval = de_thread(me);
if (retval)
goto out;
@@ -1277,6 +1317,8 @@ int flush_old_exec(struct linux_binprm * bprm)
*/
set_mm_exe_file(bprm->mm, bprm->file);
+ would_dump(bprm, bprm->file);
+
/*
* Release all of the old mmap stuff
*/
@@ -1286,18 +1328,31 @@ int flush_old_exec(struct linux_binprm * bprm)
goto out;
/*
- * After clearing bprm->mm (to mark that current is using the
- * prepared mm now), we have nothing left of the original
+ * After setting bprm->called_exec_mmap (to mark that current is
+ * using the prepared mm now), we have nothing left of the original
* process. If anything from here on returns an error, the check
* in search_binary_handler() will SEGV current.
*/
+ bprm->called_exec_mmap = 1;
bprm->mm = NULL;
+#ifdef CONFIG_POSIX_TIMERS
+ exit_itimers(me->signal);
+ flush_itimer_signals();
+#endif
+
+ /*
+ * Make the signal table private.
+ */
+ retval = unshare_sighand(me);
+ if (retval)
+ goto out;
+
set_fs(USER_DS);
- current->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD |
+ me->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD |
PF_NOFREEZE | PF_NO_SETAFFINITY);
flush_thread();
- current->personality &= ~bprm->per_clear;
+ me->personality &= ~bprm->per_clear;
/*
* We have to apply CLOEXEC before we change whether the process is
@@ -1305,7 +1360,7 @@ int flush_old_exec(struct linux_binprm * bprm)
* trying to access the should-be-closed file descriptors of a process
* undergoing exec(2).
*/
- do_close_on_exec(current->files);
+ do_close_on_exec(me->files);
return 0;
out:
@@ -1386,7 +1441,7 @@ void setup_new_exec(struct linux_binprm * bprm)
/* An exec changes our domain. We are no longer part of the thread
group */
- current->self_exec_id++;
+ WRITE_ONCE(current->self_exec_id, current->self_exec_id + 1);
flush_signal_handlers(current, 0);
}
EXPORT_SYMBOL(setup_new_exec);
@@ -1424,6 +1479,8 @@ static void free_bprm(struct linux_binprm *bprm)
{
free_arg_pages(bprm);
if (bprm->cred) {
+ if (bprm->called_exec_mmap)
+ mutex_unlock(&current->signal->exec_update_mutex);
mutex_unlock(&current->signal->cred_guard_mutex);
abort_creds(bprm->cred);
}
@@ -1473,6 +1530,7 @@ void install_exec_creds(struct linux_binprm *bprm)
* credentials; any time after this it may be unlocked.
*/
security_bprm_committed_creds(bprm);
+ mutex_unlock(&current->signal->exec_update_mutex);
mutex_unlock(&current->signal->cred_guard_mutex);
}
EXPORT_SYMBOL(install_exec_creds);
@@ -1664,7 +1722,7 @@ int search_binary_handler(struct linux_binprm *bprm)
read_lock(&binfmt_lock);
put_binfmt(fmt);
- if (retval < 0 && !bprm->mm) {
+ if (retval < 0 && bprm->called_exec_mmap) {
/* we got to flush_old_exec() and failed after it */
read_unlock(&binfmt_lock);
force_sigsegv(SIGSEGV);
@@ -1820,8 +1878,6 @@ static int __do_execve_file(int fd, struct filename *filename,
if (retval < 0)
goto out;
- would_dump(bprm, bprm->file);
-
retval = exec_binprm(bprm);
if (retval < 0)
goto out;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-29 04:07:36 +0000