CVE-2026-23211: mm, swap: restore swap_space attr aviod kernel panic

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-02-18 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: mm, swap: restore swap_space attr aviod kernel panic commit 8b47299a411a ("mm, swap: mark swap address space ro and add context debug check") made the swap address space read-only. It may lead to kernel panic if arch_prepare_to_swap returns a failure under heavy memory pressure as follows, el1_abort+0x40/0x64 el1h_64_sync_handler+0x48/0xcc el1h_64_sync+0x84/0x88 errseq_set+0x4c/0xb8 (P) __filemap_set_wb_err+0x20/0xd0 shrink_folio_list+0xc20/0x11cc evict_folios+0x1520/0x1be4 try_to_shrink_lruvec+0x27c/0x3dc shrink_one+0x9c/0x228 shrink_node+0xb3c/0xeac do_try_to_free_pages+0x170/0x4f0 try_to_free_pages+0x334/0x534 __alloc_pages_direct_reclaim+0x90/0x158 __alloc_pages_slowpath+0x334/0x588 __alloc_frozen_pages_noprof+0x224/0x2fc __folio_alloc_noprof+0x14/0x64 vma_alloc_zeroed_movable_folio+0x34/0x44 do_pte_missing+0xad4/0x1040 handle_mm_fault+0x4a4/0x790 do_page_fault+0x288/0x5f8 do_translation_fault+0x38/0x54 do_mem_abort+0x54/0xa8 Restore swap address space as not ro to avoid the panic.

Affected products

Linux kernel: from 6.18 before 6.18.9; 6.19-rc1, 6.19-rc2, 6.19-rc3, 6.19-rc4, 6.19-rc5, 6.19-rc6 (+1) — fixed in 6.18.9

How to fix

Upgrade to a fixed version: Linux kernel 6.18.9. Check the vendor advisory for mitigations.

References

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