close_range: unshare all fds for CLOSE_RANGE_UNSHARE | CLOSE_RANGE_CLOEXEC

[linux-2.6-microblaze.git] / fs / exec.c

diff --git a/fs/exec.c b/fs/exec.c
index aee36e5..5d4d520 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -757,8 +757,8 @@ int setup_arg_pages(struct linux_binprm *bprm,
 #ifdef CONFIG_STACK_GROWSUP
        /* Limit stack size */
        stack_base = bprm->rlim_stack.rlim_max;
-       if (stack_base > STACK_SIZE_MAX)
-               stack_base = STACK_SIZE_MAX;
+
+       stack_base = calc_max_stack_size(stack_base);
 
        /* Add space for stack randomization. */
        stack_base += (STACK_RND_MASK << PAGE_SHIFT);
@@ -966,8 +966,8 @@ 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.
+ * On success, this function returns with exec_update_lock
+ * held for writing.
  */
 static int exec_mmap(struct mm_struct *mm)
 {
@@ -982,7 +982,7 @@ static int exec_mmap(struct mm_struct *mm)
        if (old_mm)
                sync_mm_rss(old_mm);
 
-       ret = mutex_lock_killable(&tsk->signal->exec_update_mutex);
+       ret = down_write_killable(&tsk->signal->exec_update_lock);
        if (ret)
                return ret;
 
@@ -996,7 +996,7 @@ static int exec_mmap(struct mm_struct *mm)
                mmap_read_lock(old_mm);
                if (unlikely(old_mm->core_state)) {
                        mmap_read_unlock(old_mm);
-                       mutex_unlock(&tsk->signal->exec_update_mutex);
+                       up_write(&tsk->signal->exec_update_lock);
                        return -EINTR;
                }
        }
@@ -1258,6 +1258,16 @@ int begin_new_exec(struct linux_binprm * bprm)
        if (retval)
                goto out;
 
+       /*
+        * Cancel any io_uring activity across execve
+        */
+       io_uring_task_cancel();
+
+       /* Ensure the files table is not shared. */
+       retval = unshare_files();
+       if (retval)
+               goto out;
+
        /*
         * Must be called _before_ exec_mmap() as bprm->mm is
         * not visibile until then. This also enables the update
@@ -1385,7 +1395,7 @@ int begin_new_exec(struct linux_binprm * bprm)
        return 0;
 
 out_unlock:
-       mutex_unlock(&me->signal->exec_update_mutex);
+       up_write(&me->signal->exec_update_lock);
 out:
        return retval;
 }
@@ -1426,7 +1436,7 @@ void setup_new_exec(struct linux_binprm * bprm)
         * some architectures like powerpc
         */
        me->mm->task_size = TASK_SIZE;
-       mutex_unlock(&me->signal->exec_update_mutex);
+       up_write(&me->signal->exec_update_lock);
        mutex_unlock(&me->signal->cred_guard_mutex);
 }
 EXPORT_SYMBOL(setup_new_exec);
@@ -1779,21 +1789,11 @@ static int bprm_execve(struct linux_binprm *bprm,
                       int fd, struct filename *filename, int flags)
 {
        struct file *file;
-       struct files_struct *displaced;
        int retval;
 
-       /*
-        * Cancel any io_uring activity across execve
-        */
-       io_uring_task_cancel();
-
-       retval = unshare_files(&displaced);
-       if (retval)
-               return retval;
-
        retval = prepare_bprm_creds(bprm);
        if (retval)
-               goto out_files;
+               return retval;
 
        check_unsafe_exec(bprm);
        current->in_execve = 1;
@@ -1808,11 +1808,14 @@ static int bprm_execve(struct linux_binprm *bprm,
        bprm->file = file;
        /*
         * Record that a name derived from an O_CLOEXEC fd will be
-        * inaccessible after exec. Relies on having exclusive access to
-        * current->files (due to unshare_files above).
+        * inaccessible after exec.  This allows the code in exec to
+        * choose to fail when the executable is not mmaped into the
+        * interpreter and an open file descriptor is not passed to
+        * the interpreter.  This makes for a better user experience
+        * than having the interpreter start and then immediately fail
+        * when it finds the executable is inaccessible.
         */
-       if (bprm->fdpath &&
-           close_on_exec(fd, rcu_dereference_raw(current->files->fdt)))
+       if (bprm->fdpath && get_close_on_exec(fd))
                bprm->interp_flags |= BINPRM_FLAGS_PATH_INACCESSIBLE;
 
        /* Set the unchanging part of bprm->cred */
@@ -1830,8 +1833,6 @@ static int bprm_execve(struct linux_binprm *bprm,
        rseq_execve(current);
        acct_update_integrals(current);
        task_numa_free(current, false);
-       if (displaced)
-               put_files_struct(displaced);
        return retval;
 
 out:
@@ -1848,10 +1849,6 @@ out_unmark:
        current->fs->in_exec = 0;
        current->in_execve = 0;
 
-out_files:
-       if (displaced)
-               reset_files_struct(displaced);
-
        return retval;
 }