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CVE-2026-31450HIGH· 8.8MITRENVD대응게시일: 2026. 04. 22.수정일: 2026. 07. 14.CNA: 416baaa9-dc9f-4396-8d5f-8c081fb06d67Modified

In the Linux kernel, the following vulnerability has been resolved: ext4: publish jinode after initialization ext4_inode_attach_jinode() p

위협 신호 · CVSS · EPSS · KEV

정기 패치· 높은 악용 신호 없음
CVSS
8.8high

이론적 심각도 점수

EPSS
0.5%상위 58.0%

30일 내 악용 확률 예측

KEV
미등재

실측 악용 기록 없음

권장 대응 기한14일 이내CISA SSVC 기준

2주 이내 패치 — 우선 조치 대상

완전 장악외부 노출· KEV 미등재 · 자동화 어려움 · 완전 장악 · 외부 노출

CVSS 벡터 · 메트릭

악용 경로
공격 벡터네트워크
공격 복잡도낮음
필요 권한낮음
사용자 상호작용불필요
범위불변
영향
기밀성 영향높음
무결성 영향높음
가용성 영향높음
버전별 점수
CVSS 3.18.8HIGH· 악용성 2.8· 영향도 5.9
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

약점 (CWE)

  • CWE-476

    NULL 포인터 역참조 — NULL 참조로 서비스 충돌(DoS) 유발.

상세 설명

In the Linux kernel, the following vulnerability has been resolved:

ext4: publish jinode after initialization

ext4_inode_attach_jinode() publishes ei->jinode to concurrent users.
It used to set ei->jinode before jbd2_journal_init_jbd_inode(),
allowing a reader to observe a non-NULL jinode with i_vfs_inode
still unset.

The fast commit flush path can then pass this jinode to
jbd2_wait_inode_data(), which dereferences i_vfs_inode->i_mapping and
may crash.

Below is the crash I observe:

bash
 1BUG: unable to handle page fault for address: 000000010beb47f4
 2PGD 110e51067 P4D 110e51067 PUD 0
 3Oops: Oops: 0000 [#1] SMP NOPTI
 4CPU: 1 UID: 0 PID: 4850 Comm: fc_fsync_bench_ Not tainted 6.18.0-00764-g795a690c06a5 #1 PREEMPT(voluntary)
 5Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.17.0-2-2 04/01/2014
 6RIP: 0010:xas_find_marked+0x3d/0x2e0
 7Code: e0 03 48 83 f8 02 0f 84 f0 01 00 00 48 8b 47 08 48 89 c3 48 39 c6 0f 82 fd 01 00 00 48 85 c9 74 3d 48 83 f9 03 77 63 4c 8b 0f <49> 8b 71 08 48 c7 47 18 00 00 00 00 48 89 f1 83 e1 03 48 83 f9 02
 8RSP: 0018:ffffbbee806e7bf0 EFLAGS: 00010246
 9RAX: 000000000010beb4 RBX: 000000000010beb4 RCX: 0000000000000003
10RDX: 0000000000000001 RSI: 0000002000300000 RDI: ffffbbee806e7c10
11RBP: 0000000000000001 R08: 0000002000300000 R09: 000000010beb47ec
12R10: ffff9ea494590090 R11: 0000000000000000 R12: 0000002000300000
13R13: ffffbbee806e7c90 R14: ffff9ea494513788 R15: ffffbbee806e7c88
14FS: 00007fc2f9e3e6c0(0000) GS:ffff9ea6b1444000(0000) knlGS:0000000000000000
15CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
16CR2: 000000010beb47f4 CR3: 0000000119ac5000 CR4: 0000000000750ef0
17PKRU: 55555554
18Call Trace:
19<TASK>
20filemap_get_folios_tag+0x87/0x2a0
21__filemap_fdatawait_range+0x5f/0xd0
22? srso_alias_return_thunk+0x5/0xfbef5
23? __schedule+0x3e7/0x10c0
24? srso_alias_return_thunk+0x5/0xfbef5
25? srso_alias_return_thunk+0x5/0xfbef5
26? srso_alias_return_thunk+0x5/0xfbef5
27? preempt_count_sub+0x5f/0x80
28? srso_alias_return_thunk+0x5/0xfbef5
29? cap_safe_nice+0x37/0x70
30? srso_alias_return_thunk+0x5/0xfbef5
31? preempt_count_sub+0x5f/0x80
32? srso_alias_return_thunk+0x5/0xfbef5
33filemap_fdatawait_range_keep_errors+0x12/0x40
34ext4_fc_commit+0x697/0x8b0
35? ext4_file_write_iter+0x64b/0x950
36? srso_alias_return_thunk+0x5/0xfbef5
37? preempt_count_sub+0x5f/0x80
38? srso_alias_return_thunk+0x5/0xfbef5
39? vfs_write+0x356/0x480
40? srso_alias_return_thunk+0x5/0xfbef5
41? preempt_count_sub+0x5f/0x80
42ext4_sync_file+0xf7/0x370
43do_fsync+0x3b/0x80
44? syscall_trace_enter+0x108/0x1d0
45__x64_sys_fdatasync+0x16/0x20
46do_syscall_64+0x62/0x2c0
47entry_SYSCALL_64_after_hwframe+0x76/0x7e
48...

Fix this by initializing the jbd2_inode first.
Use smp_wmb() and WRITE_ONCE() to publish ei->jinode after
initialization. Readers use READ_ONCE() to fetch the pointer.

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영향받는 제품·버전

  • linux linux_kernel3.11.1 - 5.10.253
    linux
  • linux linux_kernel5.11 - 5.15.203
    linux
  • linux linux_kernel5.16 - 6.1.168
    linux
  • linux linux_kernel6.2 - 6.6.134
    linux
  • linux linux_kernel6.7 - 6.12.81
    linux
  • linux linux_kernel6.13 - 6.18.21
    linux
  • linux linux_kernel6.19 - 6.19.11
    linux
  • linux linux_kernel
    linux
  • linux linux_kernel
    linux
  • linux linux_kernel
    linux
  • linux linux_kernel
    linux
  • linux linux_kernel
    linux
  • linux linux_kernel
    linux
  • linux linux_kernel
    linux
  • linux linux_kernel
    linux

영향받는 구성 (CPE) 9

  • linux linux_kernel≥ 3.11.1 < 5.10.253cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
  • linux linux_kernel 3.11cpe:2.3:o:linux:linux_kernel:3.11:-:*:*:*:*:*:*
  • linux linux_kernel 3.11cpe:2.3:o:linux:linux_kernel:3.11:rc6:*:*:*:*:*:*
  • linux linux_kernel 3.11cpe:2.3:o:linux:linux_kernel:3.11:rc7:*:*:*:*:*:*
  • linux linux_kernel 7.0cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
  • linux linux_kernel 7.0cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
  • linux linux_kernel 7.0cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
  • linux linux_kernel 7.0cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
  • linux linux_kernel 7.0cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*

참고 자료 10

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