CVE-2024-27022fork: defer linking file vma until vma is fully initialized

Official description

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 packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/087de0e15e6830ed630c793fa4bebd62e8348da1
• https://git.kernel.org/stable/c/2e5cbab8ccbfc7d4a3d8a21d3c2a1f2c1aa29b5b
• https://git.kernel.org/stable/c/abdb88dd272bbeb93efe01d8e0b7b17e24af3a34
• https://git.kernel.org/stable/c/35e351780fa9d8240dd6f7e4f245f9ea37e96c19
• https://git.kernel.org/stable/c/0c42f7e039aba3de6d7dbf92da708e2b2ecba557 x_transferred
• https://git.kernel.org/stable/c/04b0c41912349aff11a1bbaef6a722bd7fbb90ac x_transferred
• https://git.kernel.org/stable/c/cec11fa2eb512ebe3a459c185f4aca1d44059bbf x_transferred
• https://git.kernel.org/stable/c/dd782da470761077f4d1120e191f1a35787cda6e x_transferred
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DAMSOZXJEPUOXW33WZYWCVAY7Z5S7OOY/
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4EZ6PJW7VOZ224TD7N4JZNU6KV32ZJ53/
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GCBZZEC7L7KTWWAS2NLJK6SO3IZIL4WW/