Commit 954652b9 authored by Anthony Yznaga's avatar Anthony Yznaga Committed by Andrew Morton
Browse files

mm/mremap: fix unaccount of memory on vma_merge() failure 

Fix mremap so that only accounted memory is unaccounted if the mapping is
expandable but vma_merge() fails.

Link: https://lkml.kernel.org/r/20230830004549.16131-1-anthony.yznaga@oracle.com


Fixes: fdbef614 ("mm/mremap: don't account pages in vma_to_resize()")
Signed-off-by: default avatarAnthony Yznaga <anthony.yznaga@oracle.com>
Acked-by: default avatarBrian Geffon <bgeffon@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent b6afcb94

mm/mremap.c

+3 −1
Original line number Diff line number Diff line
@@ -1037,12 +1037,14 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, 
			pgoff_t extension_pgoff = vma->vm_pgoff +

				((extension_start - vma->vm_start) >> PAGE_SHIFT);

			VMA_ITERATOR(vmi, mm, extension_start);

			long charged = 0;



			if (vma->vm_flags & VM_ACCOUNT) {

				if (security_vm_enough_memory_mm(mm, pages)) {

					ret = -ENOMEM;

					goto out;

				}

				charged = pages;

			}



			/*
@@ -1058,7 +1060,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, 
				vma->vm_file, extension_pgoff, vma_policy(vma),

				vma->vm_userfaultfd_ctx, anon_vma_name(vma));

			if (!vma) {

				vm_unacct_memory(pages);

				vm_unacct_memory(charged);

				ret = -ENOMEM;

				goto out;

			}