Description
In the Linux kernel, the following vulnerability has been resolved: mm: hugetlb: fix UAF in hugetlb_handle_userfault The vma_lock and hugetlb_fault_mutex are dropped before handling userfault and reacquire them again after handle_userfault(), but reacquire the vma_lock could lead to UAF[1,2] due to the following race, hugetlb_fault hugetlb_no_page /*unlock vma_lock */ hugetlb_handle_userfault handle_userfault /* unlock mm->mmap_lock*/ vm_mmap_pgoff do_mmap mmap_region munmap_vma_range /* clean old vma */ /* lock vma_lock again <--- UAF */ /* unlock vma_lock */ Since the vma_lock will unlock immediately after hugetlb_handle_userfault(), let's drop the unneeded lock and unlock in hugetlb_handle_userfault() to fix the issue. [1] https://lore.kernel.org/linux-mm/[email protected]/ [2] https://lore.kernel.org/linux-mm/[email protected]/
References5
- git.kernel.org/stable/c/0db2efb3bff879566f05341d94c3de00ac95c4cc
- git.kernel.org/stable/c/45c33966759ea1b4040c08dacda99ef623c0ca29
- git.kernel.org/stable/c/78504bcedb2f1bbfb353b4d233c24d641c4dda33
- git.kernel.org/stable/c/958f32ce832ba781ac20e11bb2d12a9352ea28fc
- git.kernel.org/stable/c/dd691973f67b2800a97db723b1ff6f07fdcf7f5a
Metrics
- CVSS 3.1
-
7.8
HIGH
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 6 · as of 11 November 2026
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