CVE-2024-27022 fork: defer linking file vma until vma is fully initialized
A race condition in the Linux kernel's fork process involving hugetlbfs can lead to a system crash or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-27022?
CVE-2024-27022 is a high-severity vulnerability in Linux kernel, published on 1 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.
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.
Weakness: CWE-908
Which versions are affected by CVE-2024-27022?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-27022?
Apply the vendor's patch.
Is CVE-2024-27022 being exploited?
There is no known exploitation of CVE-2024-27022 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-42186, BELL-CVE-2024-27022, DEBIAN-CVE-2024-27022, GHSA-rvcc-g859-q9qh, ROOT-OS-UBUNTU-2404-CVE-2024-27022, UBUNTU-CVE-2024-27022.