csirt@kutim:~/threat-intel/cve/CVE-2026-63796

Katalog CVE

CVSS 8.8 · High EPSS 0,48%

Kerentanan Out-of-bounds Read pada linux kernel. Skor CVSS 3.1 8.8 (High) menurut CNA.

Deskripsi (NVD)

In the Linux kernel, the following vulnerability has been resolved: ocfs2: reject oversized group bitmap descriptors ocfs2_validate_gd_parent() only bounds bg_bits against the parent allocator's chain geometry. A malicious descriptor can still claim a bg_size/bg_bits pair that exceeds the bitmap bytes that physically fit in the group descriptor block, so later bitmap scans and bit updates can run past bg_bitmap. Add a physical-cap check based on ocfs2_group_bitmap_size() for the parent allocator type and reject descriptors whose bg_size or bg_bits exceed that capacity. Keep the existing chain geometry check so both the on-disk bitmap layout and the allocator metadata must agree before the descriptor is used. Validation reproduced this kernel report: KASAN use-after-free in _find_next_bit+0x7f/0xc0 Read of size 8 Call trace: dump_stack_lvl+0x66/0xa0 (?:?) print_report+0xd0/0x630 (?:?) _find_next_bit+0x7f/0xc0 (?:?) srso_alias_return_thunk+0x5/0xfbef5 (?:?) __virt_addr_valid+0x188/0x2f0 (?:?) kasan_report+0xe4/0x120 (?:?) ocfs2_find_max_contig_free_bits+0x35/0x70 (fs/ocfs2/suballoc.c:1375) ocfs2_block_group_set_bits+0x472/0x4b0 (fs/ocfs2/suballoc.c:1457) ocfs2_cluster_group_search+0x16b/0x440 (fs/ocfs2/suballoc.c:86) ocfs2_bg_discontig_fix_result+0x1ef/0x230 (fs/ocfs2/suballoc.c:1786) ocfs2_search_chain+0x8f8/0x10a0 (fs/ocfs2/suballoc.c:1886) get_page_from_freelist+0x70e/0x2370 (?:?) lock_release+0xc6/0x290 (?:?) do_raw_spin_unlock+0x9a/0x100 (?:?) kasan_unpoison+0x27/0x60 (?:?) __bfs+0x147/0x240 (?:?) get_page_from_freelist+0x83d/0x2370 (?:?) ocfs2_claim_suballoc_bits+0x38c/0xe70 (fs/ocfs2/suballoc.c:96) sched_domains_numa_masks_clear+0x70/0xd0 (?:?) check_irq_usage+0xe8/0xb70 (?:?) __ocfs2_claim_clusters+0x18d/0x4c0 (fs/ocfs2/suballoc.c:2497) check_path+0x24/0x50 (?:?) rcu_is_watching+0x20/0x50 (?:?) check_prev_add+0xfd/0xd00 (?:?) ocfs2_add_clusters_in_btree+0x17d/0x810 (fs/ocfs2/suballoc.c:?) __folio_batch_add_and_move+0x1f5/0x3d0 (?:?) ocfs2_add_inode_data+0xd9/0x120 (fs/ocfs2/suballoc.c:?) filemap_add_folio+0x105/0x1f0 (?:?) ocfs2_write_begin_nolock+0x29f7/0x2f80 (fs/ocfs2/suballoc.c:3043) ocfs2_read_inode_block+0xb5/0x110 (fs/ocfs2/suballoc.c:?) down_write+0xf5/0x180 (?:?) ocfs2_write_begin+0x180/0x240 (fs/ocfs2/suballoc.c:?) __mark_inode_dirty+0x758/0x9a0 (?:?) inode_to_bdi+0x41/0x90 (?:?) balance_dirty_pages_ratelimited_flags+0xf8/0x1d0 (?:?) generic_perform_write+0x252/0x440 (?:?) mnt_put_write_access_file+0x16/0x70 (?:?) file_update_time_flags+0xe4/0x200 (?:?) ocfs2_file_write_iter+0x80a/0x1320 (fs/ocfs2/suballoc.c:?) lock_acquire+0x184/0x2f0 (?:?) ksys_write+0xd2/0x170 (?:?) apparmor_file_permission+0xf5/0x310 (?:?) read_zero+0x8d/0x140 (?:?) lock_is_held_type+0x8f/0x100 (?:?)

Rincian

Terbit di NVD
19 Juli 2026
Terakhir diubah
17 Agustus 2026
Status NVD
Analyzed
CVSS 3.1
8.8 (High), sumber CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H · uraikan di kalkulator
Jenis kelemahan (CWE)
CWE-125: Out-of-bounds Read
EPSS (30 hari)
0,48% peluang dieksploitasi; lebih tinggi dari 39,7% CVE lain

Produk dan versi terdampak

VendorProdukVersi terdampak
linux linux kernel Versi 2.6.16 hingga sebelum 5.10.260
linux linux kernel Versi 5.11 hingga sebelum 5.15.211
linux linux kernel Versi 5.16 hingga sebelum 6.1.177
linux linux kernel Versi 6.2 hingga sebelum 6.6.144
linux linux kernel Versi 6.7 hingga sebelum 6.12.95
linux linux kernel Versi 6.13 hingga sebelum 6.18.38
linux linux kernel Versi 6.19 hingga sebelum 7.1.3

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

Sumber: NVD · CVE.org · EPSS. Halaman ini disusun otomatis dari data tersebut; pembaruan terakhir 5 Okt 2026, 20:11 WITA. Kalau sistem di Perangkat Daerah memakai produk ini dan butuh bantuan, laporkan lewat kanal pelaporan.