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CVE-2026-74482: Linux

7.8

CVSS 3.1

Няма данни

Вероятност да бъде експлоатирана в следващите 30 дни (EPSS)

Няма потвърждение

Атакува се

Няма данни

Време до експлоатация

Атакува се локално, без особени условия, с обикновен потребителски вход и без действие от потребителя.

  • Експлоатация: няма данни за експлоатация
  • Атаката не може да се автоматизира

Описание

Оригинално описание

In the Linux kernel, the following vulnerability has been resolved: mm/huge_memory: unlock i_mmap_rwsem before releasing after-split folios __folio_split() keeps dereferencing the mapping after the split: shmem_uncharge(mapping->host) and remap_page() while the folios are still frozen/locked, and i_mmap_unlock_read(mapping) at the very end, after the after-split folios have been unlocked and freed. Nothing holds an inode reference across that. The split relies on @folio -- which the beyond-EOF drop loop never removes, as it starts at folio_next(folio) -- staying locked and in the page cache to hold off eviction. But the unlock loop unlocks @folio before i_mmap_unlock_read() runs. If the caller's @lock_at is a tail beyond EOF, as memory_failure() passes when splitting a poisoned tail of a shmem THP that reaches past i_size during truncation, it too is gone from the page cache; so once @folio is unlocked no locked, in-cache folio pins the inode, and a concurrent final iput() can evict and RCU-free it before i_mmap_unlock_read() touches i_mmap_rwsem: BUG: KASAN: slab-use-after-free in __up_read+0x634/0x790 i_mmap_unlock_read include/linux/fs.h:537 [inline] __folio_split+0x732/0x1640 mm/huge_memory.c:4100 try_to_split_thp_page+0xab/0x390 mm/memory-failure.c:1675 memory_failure+0x1394/0x26e0 mm/memory-failure.c:2470 Freed by task 4601: shmem_free_in_core_inode+0x54/0xb0 mm/shmem.c:5177 evict+0x57f/0xac0 fs/inode.c:870 Do every mapping dereference while @folio still pins the inode: drop i_mmap_rwsem right after remap_page(), before the loop that unlocks and frees the after-split folios, and clear @mapping so the exit path does not unlock it again. shmem_uncharge() and remap_page() already run before that point, so after this nothing past the unlock loop touches the inode or the mapping. This is now a rule the split depends on, alongside keeping @folio frozen until the page cache is updated: no inode or mapping dereference once the after-sp

Засегнати продукти

  • Linux Linux: baa355fd331424526e742d41d9b90d5f9d10f716 преди bc2f5eabaaf60ec18da70b619a8fba1bfb7dea3a; baa355fd331424526e742d41d9b90d5f9d10f716 преди f87c08060818ebb19bafed37c38244538da25097; baa355fd331424526e742d41d9b90d5f9d10f716 преди 6f5c272d71845a669e4c8ee5c72b376e29a0e6e5; baa355fd331424526e742d41d9b90d5f9d10f716 преди be106f7855f03d3128ed0ce70ba74b484a90b473; baa355fd331424526e742d41d9b90d5f9d10f716 преди e3dd774dbfd0b5bc2dbd0995221751b1234f8205; baa355fd331424526e742d41d9b90d5f9d10f716 преди 10065fb891651d9541e7a5a2db84c1e656ece4f9; baa355fd331424526e742d41d9b90d5f9d10f716 преди d640efe94d86d3be893d4c19220362546a637e90; baa355fd331424526e742d41d9b90d5f9d10f716 преди e923bd21058ea02fd0dcd3549d151d143fd036e5
  • Linux Linux: 4.8; преди 4.8; 5.10.265 до 5.10.*; 5.15.216 до 5.15.*; 6.1.183 до 6.1.*; 6.6.151 до 6.6.*; 6.12.103 до 6.12.*; 6.18.44 до 6.18.*; 7.1.8 до 7.1.*; 7.2 до *

История

  • 15 август 2026 Публикувано

Други уязвимости в Linux Linux

Първоизточници

CVE-2026-74482: Linux | freedomonline.bg