CVE-2025-68178
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:
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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)
- Probabilidad de explotación en los próximos 30 días: 0.20%
- Percentil entre todas las CVEs puntuadas: 9
- Fecha de la puntuación: 6/10/2026
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"
}