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CVE-2026-63808: Linux, грешка в паметта

9.8

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 по мрежата, без особени условия, без вход и без действие от потребителя.

CVE радар: още уязвимости от този вид

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

Описание

Оригинално описание

In the Linux kernel, the following vulnerability has been resolved: exfat: fix potential use-after-free in exfat_find_dir_entry() In exfat_find_dir_entry(), the buffer_head obtained from exfat_get_dentry() is released with brelse(bh) before the fall-through TYPE_EXTEND branch reads the directory entry through ep (which points into bh->b_data): brelse(bh); if (entry_type == TYPE_EXTEND) { ... len = exfat_extract_uni_name(ep, entry_uniname); ... } After brelse() drops our reference, nothing guarantees that the underlying page backing bh->b_data remains valid for the subsequent exfat_extract_uni_name() read. This is the same pattern fixed in commit fc961522ddbd ("exfat: Fix potential use after free in exfat_load_upcase_table()"). Move brelse(bh) so it runs after ep is no longer dereferenced on each branch. Confirmed on QEMU x86_64 with CONFIG_KASAN=y + CONFIG_DEBUG_PAGEALLOC=y + CONFIG_PAGE_POISONING=y on linux-next, using a crafted exFAT image (long filename with same-hash collisions forcing the TYPE_EXTEND path). With a debug-only invalidate_bdev() inserted between brelse(bh) and the ep read to make the stale-deref window deterministic, the unpatched kernel faults: BUG: KASAN: use-after-free in exfat_find_dir_entry+0x133b/0x15a0 BUG: unable to handle page fault for address: ffff88801a5fa0c2 Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI RIP: 0010:exfat_find_dir_entry+0x1188/0x15a0 With this patch applied, the same instrumented harness completes cleanly under the same sanitizer stack. I have not reproduced a crash on an uninstrumented kernel under ordinary reclaim; the instrumented A/B establishes the lifetime violation and that the patch closes it, not an unaided triggerability claim.

Засегнати продукти

  • Linux Linux: ca06197382bde0a3bc20215595d1c9ce20c6e341 преди e6f1a11cfb808441a43ffae9b476cc135732cd27; ca06197382bde0a3bc20215595d1c9ce20c6e341 преди e48f413c2815787b8cade2795e194e3c4cd782ef; ca06197382bde0a3bc20215595d1c9ce20c6e341 преди 06c4e1e9967d332ac33ba38b7819851089ff9359; ca06197382bde0a3bc20215595d1c9ce20c6e341 преди 8e0abc17fbd7e305802e84fe98b4950d50f9c433; ca06197382bde0a3bc20215595d1c9ce20c6e341 преди 4d101016d5e587f820b3ae2d5bb6770d86342649; ca06197382bde0a3bc20215595d1c9ce20c6e341 преди adfacfbaeae2cb760f492357cc36b41f84ef7f86; ca06197382bde0a3bc20215595d1c9ce20c6e341 преди 708b97e792945d3e4653939fd3405d71a61ad065; ca06197382bde0a3bc20215595d1c9ce20c6e341 преди 3f5f8ee9917cc2b9076ac533492d8a200edcabb8
  • Linux Linux: 5.7; преди 5.7; 5.10.260 до 5.10.*; 5.15.211 до 5.15.*; 6.1.177 до 6.1.*; 6.6.144 до 6.6.*; 6.12.95 до 6.12.*; 6.18.38 до 6.18.*; 7.1.3 до 7.1.*; от 7.2 нататък

Вид слабост

История

  • 19 юли 2026 Публикувано

Други уязвимости в Linux Linux

Първоизточници

CVE-2026-63808: Linux, грешка в паметта | freedomonline.bg