CVE-2026-72103 (GCVE-0-2026-72103)
Vulnerability from cvelistv5
Published
2026-08-15 05:52
Modified
2026-08-17 05:40
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
dm: avoid leaking the caller's thread keyring via the table device file
The refactoring in commit a28d893eb327 ("md: port block device access to file")
accidentally causes the caller's thread keyring to be kept alive long
beyond the caller's lifetime.
As a result, "cryptsetup luksSuspend" silently fails to wipe the
LUKS volume key from memory.
In detail: "cryptsetup luksOpen" uses its supposedly ephemeral thread
keyring to pass the volume key to the kernel. dm-crypt's
crypt_set_keyring_key() copies the key material into its own
crypt_config structure and then drops its own reference to the key in
the keyring with key_put().
With this fix, restoring pre-v6.9 behavior, the copy in the thread
keyring is then promptly garbage collected, such that exactly one copy
of the volume key remains. This single copy is correctly wiped from
memory on "cryptsetup luksSuspend".
Without this fix, the thread keyring and the volume key in it remains.
This second copy is only freed on "luksClose". "luksSuspend" neither
knows about this copy nor has any way to remove it, so the key remains
recoverable from RAM after a suspend that is documented to have wiped it.
This fix should not introduce new security problems, as the code is
anyway gated by CAP_SYS_ADMIN. The device-mapper core, not the calling
task, is the legitimate owner of this long-lived file.
References
| URL | Tags | |
|---|---|---|
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/md/dm.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "d3eb8451d529ea452740d1a2bc395a1d20c48133",
"status": "affected",
"version": "a28d893eb3270cf62c10dd8777af0d8452cdc072",
"versionType": "git"
},
{
"lessThan": "8ced1d242c34e342defcccdb00663354f212aae6",
"status": "affected",
"version": "a28d893eb3270cf62c10dd8777af0d8452cdc072",
"versionType": "git"
},
{
"lessThan": "f00105be6a593920e9bc7949a069d4a116888851",
"status": "affected",
"version": "a28d893eb3270cf62c10dd8777af0d8452cdc072",
"versionType": "git"
},
{
"lessThan": "981ccd97f7153d310dfa92a534525bbaf46752c2",
"status": "affected",
"version": "a28d893eb3270cf62c10dd8777af0d8452cdc072",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/md/dm.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.9"
},
{
"lessThan": "6.9",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.101",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.42",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.101",
"versionStartIncluding": "6.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.42",
"versionStartIncluding": "6.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.5",
"versionStartIncluding": "6.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "6.9",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm: avoid leaking the caller\u0027s thread keyring via the table device file\n\nThe refactoring in commit a28d893eb327 (\"md: port block device access to file\")\naccidentally causes the caller\u0027s thread keyring to be kept alive long\nbeyond the caller\u0027s lifetime.\n\nAs a result, \"cryptsetup luksSuspend\" silently fails to wipe the\nLUKS volume key from memory.\n\nIn detail: \"cryptsetup luksOpen\" uses its supposedly ephemeral thread\nkeyring to pass the volume key to the kernel. dm-crypt\u0027s\ncrypt_set_keyring_key() copies the key material into its own\ncrypt_config structure and then drops its own reference to the key in\nthe keyring with key_put().\n\nWith this fix, restoring pre-v6.9 behavior, the copy in the thread\nkeyring is then promptly garbage collected, such that exactly one copy\nof the volume key remains. This single copy is correctly wiped from\nmemory on \"cryptsetup luksSuspend\".\n\nWithout this fix, the thread keyring and the volume key in it remains.\nThis second copy is only freed on \"luksClose\". \"luksSuspend\" neither\nknows about this copy nor has any way to remove it, so the key remains\nrecoverable from RAM after a suspend that is documented to have wiped it.\n\nThis fix should not introduce new security problems, as the code is\nanyway gated by CAP_SYS_ADMIN. The device-mapper core, not the calling\ntask, is the legitimate owner of this long-lived file."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.3,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The bug is in open_table_device(), reached when CAP_SYS_ADMIN holders ioctl DM_TABLE_LOAD on /dev/mapper/control; table_load\u2192populate_table\u2192crypt_ctr\u2192dm_get_device\u2192bdev_file_open_by_dev pins caller creds. No network or physical-bus path reaches this code.\nAC:L - On every dm-crypt table load using cryptsetup\u0027s standard :logon: thread-keyring key path, bdev_file_open_by_dev unconditionally pins current_cred() into the long-lived table-device file; the extra volume-key copy then survives luksSuspend until luksClose with no race or victim-dependent heap layout.\nPR:L - ctl_ioctl requires capable(CAP_SYS_ADMIN) before dm commands; per kernel CNA guidance CAP_SYS_ADMIN obtainable in a user namespace maps to Low, and attackers routinely use namespace-level dm-crypt/LUKS administration on servers, containers, and encrypted workstations.\nUI:N - Exploitation does not require a victim to open untrusted files or mount attacker media; the latent leaked key is created by routine automated cryptsetup luksOpen/luksSuspend during boot and system suspend on LUKS deployments.\nS:U - The flaw only prevents wiping a dm-crypt volume key still held in a pinned thread keyring within the host kernel; it does not cross VM/hypervisor, IOMMU, or other separate security-authority boundaries.\nC:H - luksSuspend is documented to remove all in-kernel copies of the LUKS volume key, but the pinned logon-key payload in the leaked thread keyring remains recoverable from RAM via forensic access until luksClose, exposing the full disk-encryption key.\nI:H - Recovery of the dm-crypt volume key grants an attacker unrestricted read and write access to the entire LUKS-protected block device, enabling undetected modification of all encrypted data the suspend operation was meant to keep inaccessible.\nA:L - The pinned bdev_file keeps the caller\u0027s credentials and thread keyring (with logon key material) allocated for the dm device lifetime; this is a long-lived kernel memory retention/leak without crash, though not a service outage."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-17T05:40:17.887Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/d3eb8451d529ea452740d1a2bc395a1d20c48133"
},
{
"url": "https://git.kernel.org/stable/c/8ced1d242c34e342defcccdb00663354f212aae6"
},
{
"url": "https://git.kernel.org/stable/c/f00105be6a593920e9bc7949a069d4a116888851"
},
{
"url": "https://git.kernel.org/stable/c/981ccd97f7153d310dfa92a534525bbaf46752c2"
}
],
"title": "dm: avoid leaking the caller\u0027s thread keyring via the table device file",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-72103",
"datePublished": "2026-08-15T05:52:46.824Z",
"dateReserved": "2026-08-09T03:40:39.906Z",
"dateUpdated": "2026-08-17T05:40:17.887Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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