This is a note to let you know that I've just added the patch titled
mm: lock newly mapped VMA with corrected ordering
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-lock-newly-mapped-vma-with-corrected-ordering.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 1c7873e3364570ec89343ff4877e0f27a7b21a61 Mon Sep 17 00:00:00 2001
From: Hugh Dickins <hughd@xxxxxxxxxx>
Date: Sat, 8 Jul 2023 16:04:00 -0700
Subject: mm: lock newly mapped VMA with corrected ordering
From: Hugh Dickins <hughd@xxxxxxxxxx>
commit 1c7873e3364570ec89343ff4877e0f27a7b21a61 upstream.
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@xxxxxxxxxxxxxxx
Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
Tested-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2801,11 +2801,11 @@ cannot_expand:
if (vma_iter_prealloc(&vmi))
goto close_and_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);
vma_iter_store(&vmi, vma);
mm->map_count++;
if (vma->vm_file) {
Patches currently in stable-queue which might be from hughd@xxxxxxxxxx are
queue-6.4/mm-lock-newly-mapped-vma-with-corrected-ordering.patch
