UPSTREAM: mm: lock newly mapped VMA with corrected ordering

Lockdep is certainly right to complain about

  (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_write+0x2d/0x3f
                 but task is already holding lock:
  (&mapping->i_mmap_rwsem){+.+.}-{3:3}, at: mmap_region+0x4dc/0x6db

Invert those to the usual ordering.

Fixes: 33313a747e81 ("mm: lock newly mapped VMA which can be modified after it becomes visible")
Cc: stable@vger.kernel.org
Signed-off-by: Hugh Dickins <hughd@google.com>
Tested-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 1c7873e3364570ec89343ff4877e0f27a7b21a61)
Change-Id: I85f9cfb6ee8f3d9fefda5518c5637a7dff64bac3
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Hugh Dickins 2023-07-08 16:04:00 -07:00 committed by Greg Kroah-Hartman
parent 0d9960403c
commit 371f8d901a

View File

@ -2899,11 +2899,11 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
goto free_vma;
}
/* Lock the VMA since it is modified after insertion into VMA tree */
vma_start_write(vma);
if (vma->vm_file)
i_mmap_lock_write(vma->vm_file->f_mapping);
/* Lock the VMA since it is modified after insertion into VMA tree */
vma_start_write(vma);
mas_store_prealloc(&mas, vma);
mm->map_count++;
if (vma->vm_file) {