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CVE-2026-74351

Estado: RecibidaSin puntuar—

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

ocfs2: rebase copied fsdlm LVB pointers in locking_state

The locking_state debugfs iterator snapshots struct ocfs2_lock_res by value under ocfs2_dlm_tracking_lock and later formats that copy in ocfs2_dlm_seq_show(). That is fine for the inline fields, but the userspace fsdlm stack stores the LVB through lksb_fsdlm.sb_lvbptr. Once the iterator drops the tracking lock, a copied non-NULL sb_lvbptr still points into the original lockres owner, so teardown can free that container before the debugfs dump walks the raw LVB bytes.

Rebase the copied sb_lvbptr to the copied l_lksb before dumping the raw LVB. The seq snapshot already carries the inline LVB storage reserved in struct ocfs2_dlm_lksb, so the debugfs reader can dump the copied bytes without borrowing the original lockres lifetime.

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The buggy scenario involves two paths, with each column showing the order within that path:

Detalles técnicos trazas, registros y código del informe original
locking_state reader:                  lockres teardown:
1. ocfs2_dlm_seq_start()/next()        1. file release or another owner
   copies struct ocfs2_lock_res           teardown reaches
2. ocfs2_dlm_seq_show() formats           ocfs2_lock_res_free()
   the copied row                      2. the lockres is removed from the
3. ocfs2_dlm_lvb() follows the            tracking list
   copied sb_lvbptr                   3. the owner frees the original
                                          lockres container

Validation reproduced this kernel report:
KASAN slab-use-after-free in ocfs2_dlm_seq_show+0x1bd/0x430
RIP: 0033:0x7f8ec4b1e29d
The buggy address belongs to the object at ffff88810a1e0800 which belongs
to the cache kmalloc-1k of size 1024
The buggy address is located 368 bytes inside of freed 1024-byte region
[ffff88810a1e0800, ffff88810a1e0c00)
Read of size 1
Call trace:
  dump_stack_lvl+0x66/0xa0
  print_report+0xce/0x630
  ocfs2_dlm_seq_show+0x1bd/0x430 (fs/ocfs2/dlmglue.c:3137)
  srso_alias_return_thunk+0x5/0xfbef5
  __virt_addr_valid+0x19f/0x330
  kasan_report+0xe0/0x110
  seq_read_iter+0x29d/0x790
  seq_read+0x20a/0x280
  find_held_lock+0x2b/0x80
  rcu_read_unlock+0x18/0x70
  full_proxy_read+0x9e/0xd0
  vfs_read+0x12c/0x590
  ksys_read+0xd2/0x170
  do_user_addr_fault+0x65a/0x890
  do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)
  entry_SYSCALL_64_after_hwframe+0x77/0x7f
Allocated by task stack:
  kasan_save_stack+0x33/0x60
  kasan_save_track+0x14/0x30
  __kasan_kmalloc+0xaa/0xb0
  ocfs2_file_open+0x13e/0x300
  do_dentry_open+0x233/0x7f0
  vfs_open+0x5a/0x1b0
  path_openat+0x66d/0x1540
  do_file_open+0x186/0x2b0
  do_sys_openat2+0xce/0x150
  __x64_sys_openat+0xd0/0x140
  do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)
  entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task stack:
  kasan_save_stack+0x33/0x60
  kasan_save_track+0x14/0x30
  kasan_save_free_info+0x3b/0x60
  __kasan_slab_free+0x5f/0x80
  kfree+0x313/0x590
  ocfs2_file_release+0x138/0x260
  __fput+0x1df/0x4b0
  fput_close_sync+0xd2/0x170
  __x64_sys_close+0x55/0x90
  do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)
  entry_SYSCALL_64_after_hwframe+0x77/0x7f

CVSS

NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Linux — Linux KernelAI

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-74351",
  "cveTags": [],
  "metrics": {},
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "cf4d8d75d8aba537a19b313a9364fd08ddbd5622",
              "lessThan": "185427b5f7a209254c85c18aad5a4a8e009b2f30",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "cf4d8d75d8aba537a19b313a9364fd08ddbd5622",
              "lessThan": "07aa4a8ebacde3d0ba50f60d2964f274ee7629bc",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "cf4d8d75d8aba537a19b313a9364fd08ddbd5622",
              "lessThan": "e037c1250cc90e7aacb002357d1b0399fc65ecfc",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "cf4d8d75d8aba537a19b313a9364fd08ddbd5622",
              "lessThan": "6b38a5b8ee951e5b244e9a3c3d28d0f5e7c51411",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "cf4d8d75d8aba537a19b313a9364fd08ddbd5622",
              "lessThan": "8614a8f7e81edd34c9f67e454e7024fd12a2a341",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "cf4d8d75d8aba537a19b313a9364fd08ddbd5622",
              "lessThan": "bb44a7690a4d553da705919cf666a80f5ca9011c",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "cf4d8d75d8aba537a19b313a9364fd08ddbd5622",
              "lessThan": "610a0d2a35496738e1472fb0f318d5008a1c634f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "cf4d8d75d8aba537a19b313a9364fd08ddbd5622",
              "lessThan": "93612d48fa42b3d1a637eb9279e15281c611c000",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "fs/ocfs2/dlmglue.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.26"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "2.6.26",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/ocfs2/dlmglue.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-15T06:22:36.383",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/07aa4a8ebacde3d0ba50f60d2964f274ee7629bc",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/185427b5f7a209254c85c18aad5a4a8e009b2f30",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/610a0d2a35496738e1472fb0f318d5008a1c634f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6b38a5b8ee951e5b244e9a3c3d28d0f5e7c51411",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/8614a8f7e81edd34c9f67e454e7024fd12a2a341",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/93612d48fa42b3d1a637eb9279e15281c611c000",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/bb44a7690a4d553da705919cf666a80f5ca9011c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e037c1250cc90e7aacb002357d1b0399fc65ecfc",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: rebase copied fsdlm LVB pointers in locking_state\n\nThe locking_state debugfs iterator snapshots struct ocfs2_lock_res by\nvalue under ocfs2_dlm_tracking_lock and later formats that copy in\nocfs2_dlm_seq_show().  That is fine for the inline fields, but the\nuserspace fsdlm stack stores the LVB through lksb_fsdlm.sb_lvbptr.  Once\nthe iterator drops the tracking lock, a copied non-NULL sb_lvbptr still\npoints into the original lockres owner, so teardown can free that\ncontainer before the debugfs dump walks the raw LVB bytes.\n\nRebase the copied sb_lvbptr to the copied l_lksb before dumping the raw\nLVB.  The seq snapshot already carries the inline LVB storage reserved in\nstruct ocfs2_dlm_lksb, so the debugfs reader can dump the copied bytes\nwithout borrowing the original lockres lifetime.\n\nThe buggy scenario involves two paths, with each column showing the order\nwithin that path:\n\nlocking_state reader:                  lockres teardown:\n1. ocfs2_dlm_seq_start()/next()        1. file release or another owner\n   copies struct ocfs2_lock_res           teardown reaches\n2. ocfs2_dlm_seq_show() formats           ocfs2_lock_res_free()\n   the copied row                      2. the lockres is removed from the\n3. ocfs2_dlm_lvb() follows the            tracking list\n   copied sb_lvbptr                   3. the owner frees the original\n                                          lockres container\n\nValidation reproduced this kernel report:\nKASAN slab-use-after-free in ocfs2_dlm_seq_show+0x1bd/0x430\nRIP: 0033:0x7f8ec4b1e29d\nThe buggy address belongs to the object at ffff88810a1e0800 which belongs\nto the cache kmalloc-1k of size 1024\nThe buggy address is located 368 bytes inside of freed 1024-byte region\n[ffff88810a1e0800, ffff88810a1e0c00)\nRead of size 1\nCall trace:\n  dump_stack_lvl+0x66/0xa0\n  print_report+0xce/0x630\n  ocfs2_dlm_seq_show+0x1bd/0x430 (fs/ocfs2/dlmglue.c:3137)\n  srso_alias_return_thunk+0x5/0xfbef5\n  __virt_addr_valid+0x19f/0x330\n  kasan_report+0xe0/0x110\n  seq_read_iter+0x29d/0x790\n  seq_read+0x20a/0x280\n  find_held_lock+0x2b/0x80\n  rcu_read_unlock+0x18/0x70\n  full_proxy_read+0x9e/0xd0\n  vfs_read+0x12c/0x590\n  ksys_read+0xd2/0x170\n  do_user_addr_fault+0x65a/0x890\n  do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)\n  entry_SYSCALL_64_after_hwframe+0x77/0x7f\nAllocated by task stack:\n  kasan_save_stack+0x33/0x60\n  kasan_save_track+0x14/0x30\n  __kasan_kmalloc+0xaa/0xb0\n  ocfs2_file_open+0x13e/0x300\n  do_dentry_open+0x233/0x7f0\n  vfs_open+0x5a/0x1b0\n  path_openat+0x66d/0x1540\n  do_file_open+0x186/0x2b0\n  do_sys_openat2+0xce/0x150\n  __x64_sys_openat+0xd0/0x140\n  do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)\n  entry_SYSCALL_64_after_hwframe+0x77/0x7f\nFreed by task stack:\n  kasan_save_stack+0x33/0x60\n  kasan_save_track+0x14/0x30\n  kasan_save_free_info+0x3b/0x60\n  __kasan_slab_free+0x5f/0x80\n  kfree+0x313/0x590\n  ocfs2_file_release+0x138/0x260\n  __fput+0x1df/0x4b0\n  fput_close_sync+0xd2/0x170\n  __x64_sys_close+0x55/0x90\n  do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)\n  entry_SYSCALL_64_after_hwframe+0x77/0x7f"
    }
  ],
  "lastModified": "2026-08-17T06:19:29.780",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}