CVE-2026-90149
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: NFSv4/flexfiles: fix NULL dereference for NFSv4.0 data servers flexfiles accepts NFSv4.0 data servers, but two NFSv4 code paths assume the data server client has a session. Unlike NFSv4.1+, an NFSv4.0 client has no session (clp->cl_session is NULL; it uses clp->cl_slot_tbl), so I/O to a v4.0 flexfiles DS oopses: - nfs4_init_ds_session() dereferences clp->cl_session->session_state while seeding the DS lease. It also only seeds cl_lease_time when NFS4_SESSION_INITING is set; without a session that never happens, so cl_lease_time stays 0 and nfs4_renew_state() busy-loops, requeuing every 5 seconds. Seed the lease whenever there is no session and return before touching session state. - ff_layout_async_handle_error_v4() dereferences clp->cl_session->fc_slot_table on every DS I/O error. Fall back to the v4.0 transport slot table (clp->cl_slot_tbl) when there is no session.
Severity
HIGH
CVSS score
7.5
(v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-09-17 17:17:07.830000
Last modified
2026-10-30 13:20:43.453000
View original CVE JSON
{
"id": "CVE-2026-90149",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-17T17:17:07.830",
"lastModified": "2026-10-30T13:20:43.453",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSv4/flexfiles: fix NULL dereference for NFSv4.0 data servers\n\nflexfiles accepts NFSv4.0 data servers, but two NFSv4 code paths assume\nthe data server client has a session. Unlike NFSv4.1+, an NFSv4.0 client\nhas no session (clp->cl_session is NULL; it uses clp->cl_slot_tbl), so\nI/O to a v4.0 flexfiles DS oopses:\n\n - nfs4_init_ds_session() dereferences clp->cl_session->session_state\n while seeding the DS lease. It also only seeds cl_lease_time when\n NFS4_SESSION_INITING is set; without a session that never happens, so\n cl_lease_time stays 0 and nfs4_renew_state() busy-loops, requeuing\n every 5 seconds. Seed the lease whenever there is no session and\n return before touching session state.\n\n - ff_layout_async_handle_error_v4() dereferences\n clp->cl_session->fc_slot_table on every DS I/O error. Fall back to the\n v4.0 transport slot table (clp->cl_slot_tbl) when there is no session."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"fs/nfs/flexfilelayout/flexfilelayout.c",
"fs/nfs/nfs4session.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "a7878ca140084ec267ede48fce64d7e60f6d873e",
"lessThan": "e55d7fec8a9290f73032ee34c35dd68532809633",
"versionType": "git",
"status": "affected"
},
{
"version": "a7878ca140084ec267ede48fce64d7e60f6d873e",
"lessThan": "336b6da10021c69a8f273bbacdf7432fdc89a06f",
"versionType": "git",
"status": "affected"
},
{
"version": "a7878ca140084ec267ede48fce64d7e60f6d873e",
"lessThan": "5527af72b0100c94287bfec901b6313eeac567ca",
"versionType": "git",
"status": "affected"
},
{
"version": "a7878ca140084ec267ede48fce64d7e60f6d873e",
"lessThan": "163c16e01f53fc8eb8d0f3484ae6c382265ecbbd",
"versionType": "git",
"status": "affected"
},
{
"version": "a7878ca140084ec267ede48fce64d7e60f6d873e",
"lessThan": "436a214514e24103159aea455147d58b44a8a585",
"versionType": "git",
"status": "affected"
},
{
"version": "a7878ca140084ec267ede48fce64d7e60f6d873e",
"lessThan": "2b03ebbf8d5e8f6af4ecd6c65375232dd1ec32cc",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"fs/nfs/flexfilelayout/flexfilelayout.c",
"fs/nfs/nfs4session.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "4.12",
"status": "affected"
},
{
"version": "0",
"lessThan": "4.12",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.191",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.160",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.114",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.52",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.6",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 3.9,
"impactScore": 3.6
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/163c16e01f53fc8eb8d0f3484ae6c382265ecbbd",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/2b03ebbf8d5e8f6af4ecd6c65375232dd1ec32cc",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/336b6da10021c69a8f273bbacdf7432fdc89a06f",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/436a214514e24103159aea455147d58b44a8a585",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/5527af72b0100c94287bfec901b6313eeac567ca",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/e55d7fec8a9290f73032ee34c35dd68532809633",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}