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CVE-2025-38496

Estado: AnalizadaMedia (5.5)—

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

dm-bufio: fix sched in atomic context

If "try_verify_in_tasklet" is set for dm-verity, DM_BUFIO_CLIENT_NO_SLEEP is enabled for dm-bufio. However, when bufio tries to evict buffers, there is a chance to trigger scheduling in spin_lock_bh, the following warning is hit:

That can be reproduced by:

Detalles técnicos trazas, registros y código del informe original
BUG: sleeping function called from invalid context at drivers/md/dm-bufio.c:2745
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 123, name: kworker/2:2
preempt_count: 201, expected: 0
RCU nest depth: 0, expected: 0
4 locks held by kworker/2:2/123:
 #0: ffff88800a2d1548 ((wq_completion)dm_bufio_cache){....}-{0:0}, at: process_one_work+0xe46/0x1970
 #1: ffffc90000d97d20 ((work_completion)(&dm_bufio_replacement_work)){....}-{0:0}, at: process_one_work+0x763/0x1970
 #2: ffffffff8555b528 (dm_bufio_clients_lock){....}-{3:3}, at: do_global_cleanup+0x1ce/0x710
 #3: ffff88801d5820b8 (&c->spinlock){....}-{2:2}, at: do_global_cleanup+0x2a5/0x710
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 2 UID: 0 PID: 123 Comm: kworker/2:2 Not tainted 6.16.0-rc3-g90548c634bd0 #305 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Workqueue: dm_bufio_cache do_global_cleanup
Call Trace:
 <TASK>
 dump_stack_lvl+0x53/0x70
 __might_resched+0x360/0x4e0
 do_global_cleanup+0x2f5/0x710
 process_one_work+0x7db/0x1970
 worker_thread+0x518/0xea0
 kthread+0x359/0x690
 ret_from_fork+0xf3/0x1b0
 ret_from_fork_asm+0x1a/0x30
 </TASK>

  veritysetup format --data-block-size=4096 --hash-block-size=4096 /dev/vda /dev/vdb
  SIZE=$(blockdev --getsz /dev/vda)
  dmsetup create myverity -r --table "0 $SIZE verity 1 /dev/vda /dev/vdb 4096 4096 <data_blocks> 1 sha256 <root_hash> <salt> 1 try_verify_in_tasklet"
  mount /dev/dm-0 /mnt -o ro
  echo 102400 > /sys/module/dm_bufio/parameters/max_cache_size_bytes
  [read files in /mnt]

CVSS

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)

Linux — Linux Kernel

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2025-38496",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.5,
          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 1.8
      }
    ]
  },
  "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": "450e8dee51aa6fa1dd0f64073e88235f1a77b035",
              "lessThan": "469a39a33a9934af157299bf11c58f6e6cb53f85",
              "versionType": "git"
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            {
              "status": "affected",
              "version": "450e8dee51aa6fa1dd0f64073e88235f1a77b035",
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              "versionType": "git"
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            {
              "status": "affected",
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              "lessThan": "b1bf1a782fdf5c482215c0c661b5da98b8e75773",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "drivers/md/dm-bufio.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.4"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.4",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.6.100",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.40",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.15.8",
              "versionType": "semver",
              "lessThanOrEqual": "6.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.16",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/md/dm-bufio.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-07-28T12:15:31.847",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/3edfdb1d4ef81320dae0caa40bc24baf8c1bbb86",
      "tags": [
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
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      "tags": [
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b1bf1a782fdf5c482215c0c661b5da98b8e75773",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm-bufio: fix sched in atomic context\n\nIf \"try_verify_in_tasklet\" is set for dm-verity, DM_BUFIO_CLIENT_NO_SLEEP\nis enabled for dm-bufio. However, when bufio tries to evict buffers, there\nis a chance to trigger scheduling in spin_lock_bh, the following warning\nis hit:\n\nBUG: sleeping function called from invalid context at drivers/md/dm-bufio.c:2745\nin_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 123, name: kworker/2:2\npreempt_count: 201, expected: 0\nRCU nest depth: 0, expected: 0\n4 locks held by kworker/2:2/123:\n #0: ffff88800a2d1548 ((wq_completion)dm_bufio_cache){....}-{0:0}, at: process_one_work+0xe46/0x1970\n #1: ffffc90000d97d20 ((work_completion)(&dm_bufio_replacement_work)){....}-{0:0}, at: process_one_work+0x763/0x1970\n #2: ffffffff8555b528 (dm_bufio_clients_lock){....}-{3:3}, at: do_global_cleanup+0x1ce/0x710\n #3: ffff88801d5820b8 (&c->spinlock){....}-{2:2}, at: do_global_cleanup+0x2a5/0x710\nPreemption disabled at:\n[<0000000000000000>] 0x0\nCPU: 2 UID: 0 PID: 123 Comm: kworker/2:2 Not tainted 6.16.0-rc3-g90548c634bd0 #305 PREEMPT(voluntary)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014\nWorkqueue: dm_bufio_cache do_global_cleanup\nCall Trace:\n <TASK>\n dump_stack_lvl+0x53/0x70\n __might_resched+0x360/0x4e0\n do_global_cleanup+0x2f5/0x710\n process_one_work+0x7db/0x1970\n worker_thread+0x518/0xea0\n kthread+0x359/0x690\n ret_from_fork+0xf3/0x1b0\n ret_from_fork_asm+0x1a/0x30\n </TASK>\n\nThat can be reproduced by:\n\n  veritysetup format --data-block-size=4096 --hash-block-size=4096 /dev/vda /dev/vdb\n  SIZE=$(blockdev --getsz /dev/vda)\n  dmsetup create myverity -r --table \"0 $SIZE verity 1 /dev/vda /dev/vdb 4096 4096 <data_blocks> 1 sha256 <root_hash> <salt> 1 try_verify_in_tasklet\"\n  mount /dev/dm-0 /mnt -o ro\n  echo 102400 > /sys/module/dm_bufio/parameters/max_cache_size_bytes\n  [read files in /mnt]"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: dm-bufio: corrección de sched en contexto atómico Si \"try_verify_in_tasklet\" está configurado para dm-verity, DM_BUFIO_CLIENT_NO_SLEEP está habilitado para dm-bufio. Sin embargo, cuando bufio intenta expulsar búfer, existe la posibilidad de activar la programación en spin_lock_bh, se muestra la siguiente advertencia: BUG: sleeping function called from invalid context at drivers/md/dm-bufio.c:2745 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 123, name: kworker/2:2 preempt_count: 201, expected: 0 RCU nest depth: 0, expected: 0 4 locks held by kworker/2:2/123: #0: ffff88800a2d1548 ((wq_completion)dm_bufio_cache){....}-{0:0}, at: process_one_work+0xe46/0x1970 #1: ffffc90000d97d20 ((work_completion)(&amp;dm_bufio_replacement_work)){....}-{0:0}, at: process_one_work+0x763/0x1970 #2: ffffffff8555b528 (dm_bufio_clients_lock){....}-{3:3}, at: do_global_cleanup+0x1ce/0x710 #3: ffff88801d5820b8 (&amp;c-&gt;spinlock){....}-{2:2}, at: do_global_cleanup+0x2a5/0x710 Preemption disabled at: [&lt;0000000000000000&gt;] 0x0 CPU: 2 UID: 0 PID: 123 Comm: kworker/2:2 Not tainted 6.16.0-rc3-g90548c634bd0 #305 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 Workqueue: dm_bufio_cache do_global_cleanup Call Trace:  dump_stack_lvl+0x53/0x70 __might_resched+0x360/0x4e0 do_global_cleanup+0x2f5/0x710 process_one_work+0x7db/0x1970 worker_thread+0x518/0xea0 kthread+0x359/0x690 ret_from_fork+0xf3/0x1b0 ret_from_fork_asm+0x1a/0x30  That can be reproduced by: veritysetup format --data-block-size=4096 --hash-block-size=4096 /dev/vda /dev/vdb SIZE=$(blockdev --getsz /dev/vda) dmsetup create myverity -r --table \"0 $SIZE verity 1 /dev/vda /dev/vdb 4096 4096  1 sha256   1 try_verify_in_tasklet\" mount /dev/dm-0 /mnt -o ro echo 102400 &gt; /sys/module/dm_bufio/parameters/max_cache_size_bytes [read files in /mnt]"
    }
  ],
  "lastModified": "2026-06-17T09:16:59.000",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
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}