Vulnerability-Lookup

GHSA-8H6H-2W9H-VCG2

Vulnerability from github – Published: 2025-07-28 12:30 – Updated: 2025-11-19 18:31

Details

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:

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: 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 > /sys/module/dm_bufio/parameters/max_cache_size_bytes [read files in /mnt]

Severity

5.5 (Medium)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2025-38496"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-07-28T12:15:31Z",
    "severity": "MODERATE"
  },
  "details": "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)(\u0026dm_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 (\u0026c-\u003espinlock){....}-{2:2}, at: do_global_cleanup+0x2a5/0x710\nPreemption disabled at:\n[\u003c0000000000000000\u003e] 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 \u003cTASK\u003e\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 \u003c/TASK\u003e\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 \u003cdata_blocks\u003e 1 sha256 \u003croot_hash\u003e \u003csalt\u003e 1 try_verify_in_tasklet\"\n  mount /dev/dm-0 /mnt -o ro\n  echo 102400 \u003e /sys/module/dm_bufio/parameters/max_cache_size_bytes\n  [read files in /mnt]",
  "id": "GHSA-8h6h-2w9h-vcg2",
  "modified": "2025-11-19T18:31:17Z",
  "published": "2025-07-28T12:30:36Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-38496"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3edfdb1d4ef81320dae0caa40bc24baf8c1bbb86"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/469a39a33a9934af157299bf11c58f6e6cb53f85"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/68860d1ade385eef9fcdbf6552f061283091fdb8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b1bf1a782fdf5c482215c0c661b5da98b8e75773"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2025-38496 (GCVE-0-2025-38496)

Vulnerability from cvelistv5 – Published: 2025-07-28 11:22 – Updated: 2026-05-11 21:29

Title

dm-bufio: fix sched in atomic context

Summary

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: 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> 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 <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]

Severity

No CVSS data available.

Assigner

Linux mitre root Scorecard

References

4 references

URL	Tags
https://git.kernel.org/stable/c/469a39a33a9934af1…
https://git.kernel.org/stable/c/68860d1ade385eef9…
https://git.kernel.org/stable/c/3edfdb1d4ef81320d…
https://git.kernel.org/stable/c/b1bf1a782fdf5c482…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 450e8dee51aa6fa1dd0f64073e88235f1a77b035 , < 469a39a33a9934af157299bf11c58f6e6cb53f85 (git) Affected: 450e8dee51aa6fa1dd0f64073e88235f1a77b035 , < 68860d1ade385eef9fcdbf6552f061283091fdb8 (git) Affected: 450e8dee51aa6fa1dd0f64073e88235f1a77b035 , < 3edfdb1d4ef81320dae0caa40bc24baf8c1bbb86 (git) Affected: 450e8dee51aa6fa1dd0f64073e88235f1a77b035 , < b1bf1a782fdf5c482215c0c661b5da98b8e75773 (git)
Linux	Linux	Affected: 6.4 Unaffected: 0 , < 6.4 (semver) Unaffected: 6.6.100 , ≤ 6.6.* (semver) Unaffected: 6.12.40 , ≤ 6.12.* (semver) Unaffected: 6.15.8 , ≤ 6.15.* (semver) Unaffected: 6.16 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/md/dm-bufio.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "469a39a33a9934af157299bf11c58f6e6cb53f85",
              "status": "affected",
              "version": "450e8dee51aa6fa1dd0f64073e88235f1a77b035",
              "versionType": "git"
            },
            {
              "lessThan": "68860d1ade385eef9fcdbf6552f061283091fdb8",
              "status": "affected",
              "version": "450e8dee51aa6fa1dd0f64073e88235f1a77b035",
              "versionType": "git"
            },
            {
              "lessThan": "3edfdb1d4ef81320dae0caa40bc24baf8c1bbb86",
              "status": "affected",
              "version": "450e8dee51aa6fa1dd0f64073e88235f1a77b035",
              "versionType": "git"
            },
            {
              "lessThan": "b1bf1a782fdf5c482215c0c661b5da98b8e75773",
              "status": "affected",
              "version": "450e8dee51aa6fa1dd0f64073e88235f1a77b035",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/md/dm-bufio.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.4"
            },
            {
              "lessThan": "6.4",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.100",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.15.*",
              "status": "unaffected",
              "version": "6.15.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.16",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.100",
                  "versionStartIncluding": "6.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.40",
                  "versionStartIncluding": "6.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.15.8",
                  "versionStartIncluding": "6.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.16",
                  "versionStartIncluding": "6.4",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "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)(\u0026dm_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 (\u0026c-\u003espinlock){....}-{2:2}, at: do_global_cleanup+0x2a5/0x710\nPreemption disabled at:\n[\u003c0000000000000000\u003e] 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 \u003cTASK\u003e\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 \u003c/TASK\u003e\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 \u003cdata_blocks\u003e 1 sha256 \u003croot_hash\u003e \u003csalt\u003e 1 try_verify_in_tasklet\"\n  mount /dev/dm-0 /mnt -o ro\n  echo 102400 \u003e /sys/module/dm_bufio/parameters/max_cache_size_bytes\n  [read files in /mnt]"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T21:29:08.636Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/469a39a33a9934af157299bf11c58f6e6cb53f85"
        },
        {
          "url": "https://git.kernel.org/stable/c/68860d1ade385eef9fcdbf6552f061283091fdb8"
        },
        {
          "url": "https://git.kernel.org/stable/c/3edfdb1d4ef81320dae0caa40bc24baf8c1bbb86"
        },
        {
          "url": "https://git.kernel.org/stable/c/b1bf1a782fdf5c482215c0c661b5da98b8e75773"
        }
      ],
      "title": "dm-bufio: fix sched in atomic context",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-38496",
    "datePublished": "2025-07-28T11:22:05.091Z",
    "dateReserved": "2025-04-16T04:51:24.022Z",
    "dateUpdated": "2026-05-11T21:29:08.636Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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GHSA-8H6H-2W9H-VCG2

CVE-2025-38496 (GCVE-0-2025-38496)

Tags

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