阿里云漏洞库

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.

建议您更新当前系统或软件至最新版，完成漏洞的修复。

参考链接
https://git.kernel.org/stable/c/0c42f7e039aba3de6d7dbf92da708e2b2ecba557
https://git.kernel.org/stable/c/35e351780fa9d8240dd6f7e4f245f9ea37e96c19
https://git.kernel.org/stable/c/abdb88dd272bbeb93efe01d8e0b7b17e24af3a34
https://git.kernel.org/stable/c/cec11fa2eb512ebe3a459c185f4aca1d44059bbf

CWE-ID	漏洞类型