+ nommu-pass-null-argument-to-vma_iter_prealloc.patch added to mm-hotfixes-unstable branch

+ nommu-pass-null-argument-to-vma_iter_prealloc.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

The patch titled
     Subject: nommu: pass NULL argument to vma_iter_prealloc()
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     nommu-pass-null-argument-to-vma_iter_prealloc.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/nommu-pass-null-argument-to-vma_iter_prealloc.patch

This patch will later appear in the mm-hotfixes-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Hajime Tazaki <thehajime@gmail.com>
Subject: nommu: pass NULL argument to vma_iter_prealloc()
Date: Sat, 9 Nov 2024 07:28:34 +0900

When deleting a vma entry from a maple tree, it has to pass NULL to
vma_iter_prealloc() in order to calculate internal state of the tree, but
it passed a wrong argument.  As a result, nommu kernels crashed upon
accessing a vma iterator, such as acct_collect() reading the size of vma
entries after do_munmap().

This commit fixes this issue by passing a right argument to the
preallocation call.

Link: https://lkml.kernel.org/r/20241108222834.3625217-1-thehajime@gmail.com
Fixes: b5df09226450 ("mm: set up vma iterator for vma_iter_prealloc() calls")
Signed-off-by: Hajime Tazaki <thehajime@gmail.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/nommu.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/nommu.c~nommu-pass-null-argument-to-vma_iter_prealloc
+++ a/mm/nommu.c
@@ -573,7 +573,7 @@ static int delete_vma_from_mm(struct vm_
 	VMA_ITERATOR(vmi, vma->vm_mm, vma->vm_start);
 
 	vma_iter_config(&vmi, vma->vm_start, vma->vm_end);
-	if (vma_iter_prealloc(&vmi, vma)) {
+	if (vma_iter_prealloc(&vmi, NULL)) {
 		pr_warn("Allocation of vma tree for process %d failed\n",
 		       current->pid);
 		return -ENOMEM;
_

Patches currently in -mm which might be from thehajime@gmail.com are

nommu-pass-null-argument-to-vma_iter_prealloc.patch