CVSS 4.7 · Medium EPSS 0,12%
Kerentanan Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') pada linux kernel. Skor CVSS 3.1 4.7 (Medium) menurut NVD.
In the Linux kernel, the following vulnerability has been resolved: mm/huge_memory: fix folio isn't locked in softleaf_to_folio() On arm64 server, we found folio that get from migration entry isn't locked in softleaf_to_folio(). This issue triggers when mTHP splitting and zap_nonpresent_ptes() races, and the root cause is lack of memory barrier in softleaf_to_folio(). The race is as follows: CPU0 CPU1 deferred_split_scan() zap_nonpresent_ptes() lock folio split_folio() unmap_folio() change ptes to migration entries __split_folio_to_order() softleaf_to_folio() set flags(including PG_locked) for tail pages folio = pfn_folio(softleaf_to_pfn(entry)) smp_wmb() VM_WARN_ON_ONCE(!folio_test_locked(folio)) prep_compound_page() for tail pages In __split_folio_to_order(), smp_wmb() guarantees page flags of tail pages are visible before the tail page becomes non-compound. smp_wmb() should be paired with smp_rmb() in softleaf_to_folio(), which is missed. As a result, if zap_nonpresent_ptes() accesses migration entry that stores tail pfn, softleaf_to_folio() may see the updated compound_head of tail page before page->flags. This issue will trigger VM_WARN_ON_ONCE() in pfn_swap_entry_folio() because of the race between folio split and zap_nonpresent_ptes() leading to a folio incorrectly undergoing modification without a folio lock being held. This is a BUG_ON() before commit 93976a20345b ("mm: eliminate further swapops predicates"), which in merged in v6.19-rc1. To fix it, add missing smp_rmb() if the softleaf entry is migration entry in softleaf_to_folio() and softleaf_to_page(). [tujinjiang@huawei.com: update function name and comments]
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
· uraikan di kalkulator | Vendor | Produk | Versi terdampak |
|---|---|---|
| linux | linux kernel | Versi 4.5 hingga sebelum 5.10.253 |
| linux | linux kernel | Versi 5.11 hingga sebelum 5.15.203 |
| linux | linux kernel | Versi 5.16 hingga sebelum 6.1.168 |
| linux | linux kernel | Versi 6.2 hingga sebelum 6.6.134 |
| linux | linux kernel | Versi 6.7 hingga sebelum 6.12.81 |
| linux | linux kernel | Versi 6.13 hingga sebelum 6.18.21 |
| linux | linux kernel | Versi 6.19 hingga sebelum 6.19.11 |
| linux | linux kernel | Versi 7.0 rc1 |
| linux | linux kernel | Versi 7.0 rc2 |
| linux | linux kernel | Versi 7.0 rc3 |
| linux | linux kernel | Versi 7.0 rc4 |
| linux | linux kernel | Versi 7.0 rc5 |