Merge tag 'execve-v5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull execve updates from Kees Cook:

 - Allow unsharing time namespace on vfork+exec (Andrei Vagin)

 - Replace usage of deprecated kmap APIs (Fabio M. De Francesco)

 - Fix spelling mistake (Zhang Jiaming)

* tag 'execve-v5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  exec: Call kmap_local_page() in copy_string_kernel()
  exec: Fix a spelling mistake
  selftests/timens: add a test for vfork+exit
  fs/exec: allow to unshare a time namespace on vfork+exec

1 files changed, 9 insertions, 6 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);