In the Linux kernel, the following vulnerability has been resolved:
migrate: correct lock ordering for hugetlb file folios
Syzbot has found a deadlock (analyzed by Lance Yang):
1) Task (5749): Holds folio_lock, then tries to acquire i_mmap_rwsem(read lock).
2) Task (5754): Holds i_mmap_rwsem(write lock), then tries to acquire
folio_lock.
migrate_pages()
-> migrate_hugetlbs()
-> unmap_and_move_huge_page() <- Takes folio_lock!
-> remove_migration_ptes()
-> __rmap_walk_file()
-> i_mmap_lock_read() <- Waits for i_mmap_rwsem(read lock)!
hugetlbfs_fallocate()
-> hugetlbfs_punch_hole() <- Takes i_mmap_rwsem(write lock)!
-> hugetlbfs_zero_partial_page()
-> filemap_lock_hugetlb_folio()
-> filemap_lock_folio()
-> __filemap_get_folio <- Waits for folio_lock!
The migration path is the one taking locks in the wrong order according to
the documentation at the top of mm/rmap.c. So expand the scope of the
existing i_mmap_lock to cover the calls to remove_migration_ptes() too.
This is (mostly) how it used to be after commit c0d0381ade79. That was
removed by 336bf30eb765 for both file & anon hugetlb pages when it should
only have been removed for anon hugetlb pages.
References
Configurations
Configuration 1 (hide)
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History
No history.
Information
Published : 2026-02-04 17:16
Updated : 2026-06-17 10:20
NVD link : CVE-2026-23097
Mitre link : CVE-2026-23097
CVE.ORG link : CVE-2026-23097
JSON object : View
Products Affected
linux
- linux_kernel
CWE