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CVE-2025-68178

Estado: AplazadaSin puntuar—

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

blk-cgroup: fix possible deadlock while configuring policy

Following deadlock can be triggered easily by lockdep:

WARNING: possible circular locking dependency detected 6.17.0-rc3-00124-ga12c2658ced0 #1665 Not tainted ------------------------------------------------------ check/1334 is trying to acquire lock: ff1100011d9d0678 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_unregister_queue+0x53/0x180

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

other info that might help us debug this:

Possible unsafe locking scenario:

Leer descripción completaMostrar menos

Root cause is that queue_usage_counter is grabbed with rq_qos_mutex held in blkg_conf_prep(), while queue should be freezed before rq_qos_mutex from other context.

The blk_queue_enter() from blkg_conf_prep() is used to protect against policy deactivation, which is already protected with blkcg_mutex, hence convert blk_queue_enter() to blkcg_mutex to fix this problem. Meanwhile, consider that blkcg_mutex is held after queue is freezed from policy deactivation, also convert blkg_alloc() to use GFP_NOIO.

Detalles técnicos trazas, registros y código del informe original
but task is already holding lock:
ff1100011d9d00e0 (&q->q_usage_counter(queue)#3){++++}-{0:0}, at: del_gendisk+0xba/0x110

-> #2 (&q->q_usage_counter(queue)#3){++++}-{0:0}:
       blk_queue_enter+0x40b/0x470
       blkg_conf_prep+0x7b/0x3c0
       tg_set_limit+0x10a/0x3e0
       cgroup_file_write+0xc6/0x420
       kernfs_fop_write_iter+0x189/0x280
       vfs_write+0x256/0x490
       ksys_write+0x83/0x190
       __x64_sys_write+0x21/0x30
       x64_sys_call+0x4608/0x4630
       do_syscall_64+0xdb/0x6b0
       entry_SYSCALL_64_after_hwframe+0x76/0x7e

-> #1 (&q->rq_qos_mutex){+.+.}-{4:4}:
       __mutex_lock+0xd8/0xf50
       mutex_lock_nested+0x2b/0x40
       wbt_init+0x17e/0x280
       wbt_enable_default+0xe9/0x140
       blk_register_queue+0x1da/0x2e0
       __add_disk+0x38c/0x5d0
       add_disk_fwnode+0x89/0x250
       device_add_disk+0x18/0x30
       virtblk_probe+0x13a3/0x1800
       virtio_dev_probe+0x389/0x610
       really_probe+0x136/0x620
       __driver_probe_device+0xb3/0x230
       driver_probe_device+0x2f/0xe0
       __driver_attach+0x158/0x250
       bus_for_each_dev+0xa9/0x130
       driver_attach+0x26/0x40
       bus_add_driver+0x178/0x3d0
       driver_register+0x7d/0x1c0
       __register_virtio_driver+0x2c/0x60
       virtio_blk_init+0x6f/0xe0
       do_one_initcall+0x94/0x540
       kernel_init_freeable+0x56a/0x7b0
       kernel_init+0x2b/0x270
       ret_from_fork+0x268/0x4c0
       ret_from_fork_asm+0x1a/0x30

-> #0 (&q->sysfs_lock){+.+.}-{4:4}:
       __lock_acquire+0x1835/0x2940
       lock_acquire+0xf9/0x450
       __mutex_lock+0xd8/0xf50
       mutex_lock_nested+0x2b/0x40
       blk_unregister_queue+0x53/0x180
       __del_gendisk+0x226/0x690
       del_gendisk+0xba/0x110
       sd_remove+0x49/0xb0 [sd_mod]
       device_remove+0x87/0xb0
       device_release_driver_internal+0x11e/0x230
       device_release_driver+0x1a/0x30
       bus_remove_device+0x14d/0x220
       device_del+0x1e1/0x5a0
       __scsi_remove_device+0x1ff/0x2f0
       scsi_remove_device+0x37/0x60
       sdev_store_delete+0x77/0x100
       dev_attr_store+0x1f/0x40
       sysfs_kf_write+0x65/0x90
       kernfs_fop_write_iter+0x189/0x280
       vfs_write+0x256/0x490
       ksys_write+0x83/0x190
       __x64_sys_write+0x21/0x30
       x64_sys_call+0x4608/0x4630
       do_syscall_64+0xdb/0x6b0
       entry_SYSCALL_64_after_hwframe+0x76/0x7e

Chain exists of:
  &q->sysfs_lock --> &q->rq_qos_mutex --> &q->q_usage_counter(queue)#3

       CPU0                    CPU1
       ----                    ----
  lock(&q->q_usage_counter(queue)#3);
                               lock(&q->rq_qos_mutex);
                               lock(&q->q_usage_counter(queue)#3);
  lock(&q->sysfs_lock);

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.

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2025-68178",
  "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": "a13bd91be22318768d55470cbc0b0f4488ef9edf",
              "lessThan": "e1729523759cda2c0afb76b1c88e0d2f2ef5b7cb",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "a13bd91be22318768d55470cbc0b0f4488ef9edf",
              "lessThan": "56ac639d6fa6fbb99caee74ee1c7276fc9bb47ed",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "a13bd91be22318768d55470cbc0b0f4488ef9edf",
              "lessThan": "0585b24d71197dd9ee8cf79c168a31628c631960",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "a13bd91be22318768d55470cbc0b0f4488ef9edf",
              "lessThan": "5d726c4dbeeddef612e6bed27edd29733f4d13af",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "16398b4638b5cd8c1dc95fc940a1591a801d53ce",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6.4.4",
              "lessThan": "6.5",
              "versionType": "semver"
            }
          ],
          "programFiles": [
            "block/blk-cgroup.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.5"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.5",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.6.117",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.58",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.17.8",
              "versionType": "semver",
              "lessThanOrEqual": "6.17.*"
            },
            {
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "block/blk-cgroup.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-12-16T14:15:49.760",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0585b24d71197dd9ee8cf79c168a31628c631960",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/56ac639d6fa6fbb99caee74ee1c7276fc9bb47ed",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5d726c4dbeeddef612e6bed27edd29733f4d13af",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e1729523759cda2c0afb76b1c88e0d2f2ef5b7cb",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Deferred",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nblk-cgroup: fix possible deadlock while configuring policy\n\nFollowing deadlock can be triggered easily by lockdep:\n\nWARNING: possible circular locking dependency detected\n6.17.0-rc3-00124-ga12c2658ced0 #1665 Not tainted\n------------------------------------------------------\ncheck/1334 is trying to acquire lock:\nff1100011d9d0678 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_unregister_queue+0x53/0x180\n\nbut task is already holding lock:\nff1100011d9d00e0 (&q->q_usage_counter(queue)#3){++++}-{0:0}, at: del_gendisk+0xba/0x110\n\nwhich lock already depends on the new lock.\n\nthe existing dependency chain (in reverse order) is:\n\n-> #2 (&q->q_usage_counter(queue)#3){++++}-{0:0}:\n       blk_queue_enter+0x40b/0x470\n       blkg_conf_prep+0x7b/0x3c0\n       tg_set_limit+0x10a/0x3e0\n       cgroup_file_write+0xc6/0x420\n       kernfs_fop_write_iter+0x189/0x280\n       vfs_write+0x256/0x490\n       ksys_write+0x83/0x190\n       __x64_sys_write+0x21/0x30\n       x64_sys_call+0x4608/0x4630\n       do_syscall_64+0xdb/0x6b0\n       entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\n-> #1 (&q->rq_qos_mutex){+.+.}-{4:4}:\n       __mutex_lock+0xd8/0xf50\n       mutex_lock_nested+0x2b/0x40\n       wbt_init+0x17e/0x280\n       wbt_enable_default+0xe9/0x140\n       blk_register_queue+0x1da/0x2e0\n       __add_disk+0x38c/0x5d0\n       add_disk_fwnode+0x89/0x250\n       device_add_disk+0x18/0x30\n       virtblk_probe+0x13a3/0x1800\n       virtio_dev_probe+0x389/0x610\n       really_probe+0x136/0x620\n       __driver_probe_device+0xb3/0x230\n       driver_probe_device+0x2f/0xe0\n       __driver_attach+0x158/0x250\n       bus_for_each_dev+0xa9/0x130\n       driver_attach+0x26/0x40\n       bus_add_driver+0x178/0x3d0\n       driver_register+0x7d/0x1c0\n       __register_virtio_driver+0x2c/0x60\n       virtio_blk_init+0x6f/0xe0\n       do_one_initcall+0x94/0x540\n       kernel_init_freeable+0x56a/0x7b0\n       kernel_init+0x2b/0x270\n       ret_from_fork+0x268/0x4c0\n       ret_from_fork_asm+0x1a/0x30\n\n-> #0 (&q->sysfs_lock){+.+.}-{4:4}:\n       __lock_acquire+0x1835/0x2940\n       lock_acquire+0xf9/0x450\n       __mutex_lock+0xd8/0xf50\n       mutex_lock_nested+0x2b/0x40\n       blk_unregister_queue+0x53/0x180\n       __del_gendisk+0x226/0x690\n       del_gendisk+0xba/0x110\n       sd_remove+0x49/0xb0 [sd_mod]\n       device_remove+0x87/0xb0\n       device_release_driver_internal+0x11e/0x230\n       device_release_driver+0x1a/0x30\n       bus_remove_device+0x14d/0x220\n       device_del+0x1e1/0x5a0\n       __scsi_remove_device+0x1ff/0x2f0\n       scsi_remove_device+0x37/0x60\n       sdev_store_delete+0x77/0x100\n       dev_attr_store+0x1f/0x40\n       sysfs_kf_write+0x65/0x90\n       kernfs_fop_write_iter+0x189/0x280\n       vfs_write+0x256/0x490\n       ksys_write+0x83/0x190\n       __x64_sys_write+0x21/0x30\n       x64_sys_call+0x4608/0x4630\n       do_syscall_64+0xdb/0x6b0\n       entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nother info that might help us debug this:\n\nChain exists of:\n  &q->sysfs_lock --> &q->rq_qos_mutex --> &q->q_usage_counter(queue)#3\n\n Possible unsafe locking scenario:\n\n       CPU0                    CPU1\n       ----                    ----\n  lock(&q->q_usage_counter(queue)#3);\n                               lock(&q->rq_qos_mutex);\n                               lock(&q->q_usage_counter(queue)#3);\n  lock(&q->sysfs_lock);\n\nRoot cause is that queue_usage_counter is grabbed with rq_qos_mutex\nheld in blkg_conf_prep(), while queue should be freezed before\nrq_qos_mutex from other context.\n\nThe blk_queue_enter() from blkg_conf_prep() is used to protect against\npolicy deactivation, which is already protected with blkcg_mutex, hence\nconvert blk_queue_enter() to blkcg_mutex to fix this problem. Meanwhile,\nconsider that blkcg_mutex is held after queue is freezed from policy\ndeactivation, also convert blkg_alloc() to use GFP_NOIO."
    }
  ],
  "lastModified": "2026-06-17T09:58:41.397",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}