CVE-2024-27022
Assigner: Linux
Published: 2024-05-01T05:35:39.627Z
State: PUBLISHED
descriptions: value: In the Linux kernel, the following vulnerability has been resolved:

fork: defer linking file vma until vma is fully initialized

Thorvald reported a WARNING [1]. And the root cause is below race:

 CPU 1					CPU 2
 fork					hugetlbfs_fallocate
  dup_mmap				 hugetlbfs_punch_hole
   i_mmap_lock_write(mapping);
   vma_interval_tree_insert_after -- Child vma is visible through i_mmap tree.
   i_mmap_unlock_write(mapping);
   hugetlb_dup_vma_private -- Clear vma_lock outside i_mmap_rwsem!
					 i_mmap_lock_write(mapping);
   					 hugetlb_vmdelete_list
					  vma_interval_tree_foreach
					   hugetlb_vma_trylock_write -- Vma_lock is cleared.
   tmp->vm_ops->open -- Alloc new vma_lock outside i_mmap_rwsem!
					   hugetlb_vma_unlock_write -- Vma_lock is assigned!!!
					 i_mmap_unlock_write(mapping);

hugetlb_dup_vma_private() and hugetlb_vm_op_open() are called outside
i_mmap_rwsem lock while vma lock can be used in the same time.  Fix this
by deferring linking file vma until vma is fully initialized.  Those vmas
should be initialized first before they can be used.
affected: product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions: version: 8d9bfb260814
lessThan: 0c42f7e039ab
status: affected
versionType: git
version: 8d9bfb260814
lessThan: cec11fa2eb51
status: affected
versionType: git
version: 8d9bfb260814
lessThan: abdb88dd272b
status: affected
versionType: git
version: 8d9bfb260814
lessThan: 35e351780fa9
status: affected
versionType: git
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions: version: 6.1
status: affected
version: 0
lessThan: 6.1
status: unaffected
versionType: custom
version: 6.1.90
lessThanOrEqual: 6.1.*
status: unaffected
versionType: custom
version: 6.6.30
lessThanOrEqual: 6.6.*
status: unaffected
versionType: custom
version: 6.8.8
lessThanOrEqual: 6.8.*
status: unaffected
versionType: custom
version: 6.9
lessThanOrEqual: *
status: unaffected
versionType: original_commit_for_fix
title: fork: defer linking file vma until vma is fully initialized
x_generator: engine: bippy-d175d3acf727