CVE-2026-98897 (GCVE-0-2026-98897)
Vulnerability from cvelistv5
Published
2026-10-23 11:54
Modified
2026-10-26 06:56
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: don't hold ci->m_lock while waiting for a lease break ack
When a cifs.ko client caches a read-handle (RH) lease via deferred close
and a conflicting open arrives, ksmbd breaks the lease and waits for the
acknowledgment in wait_for_break_ack() for up to OPLOCK_WAIT_TIME (35s).
__smb_break_all_levII_oplock() runs that wait while holding ci->m_lock
for read.
cifs.ko reacts to a handle-lease break by closing the deferred handle
rather than sending a lease break acknowledgment. That close path
(close_id_del_oplock() -> opinfo_del()) takes ci->m_lock for write and
is exactly what would wake the waiter, but it blocks on the read lock
held by the waiting thread. The break is then resolved only by the 35s
timeout, so xfstests generic/001 takes ~78s with leases enabled versus
~4s with oplocks only.
Collect the target opinfos (each pinned with a reference) while holding
ci->m_lock, then break them after releasing it, matching how
smb_grant_oplock() already breaks a conflicting lease using only a
reference. The reference keeps the opinfo (and its conn and lease)
alive across the unlocked window, and a close racing the break is
handled by the existing OPLOCK_CLOSING state check. Apply the same fix
to the parent lease break paths.
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/smb/server/oplock.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "868c9038ffd4af39766d087f68c8f543a3f66635",
"status": "affected",
"version": "d1c189c6cb8b0fb7b5ee549237d27889c40c2f8b",
"versionType": "git"
},
{
"lessThan": "27a9bc968d4ae809a3f5ca2f2b136856ee613cb4",
"status": "affected",
"version": "d1c189c6cb8b0fb7b5ee549237d27889c40c2f8b",
"versionType": "git"
},
{
"status": "affected",
"version": "16ece7c5645a68efca22a0a69a7718c8e50c3232",
"versionType": "git"
},
{
"lessThan": "6.7",
"status": "affected",
"version": "6.6.35",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/smb/server/oplock.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": "6.18.*",
"status": "unaffected",
"version": "6.18.53",
"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": "6.18.53",
"versionStartIncluding": "6.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "6.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.6.35",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: don\u0027t hold ci-\u003em_lock while waiting for a lease break ack\n\nWhen a cifs.ko client caches a read-handle (RH) lease via deferred close\nand a conflicting open arrives, ksmbd breaks the lease and waits for the\nacknowledgment in wait_for_break_ack() for up to OPLOCK_WAIT_TIME (35s).\n__smb_break_all_levII_oplock() runs that wait while holding ci-\u003em_lock\nfor read.\n\ncifs.ko reacts to a handle-lease break by closing the deferred handle\nrather than sending a lease break acknowledgment. That close path\n(close_id_del_oplock() -\u003e opinfo_del()) takes ci-\u003em_lock for write and\nis exactly what would wake the waiter, but it blocks on the read lock\nheld by the waiting thread. The break is then resolved only by the 35s\ntimeout, so xfstests generic/001 takes ~78s with leases enabled versus\n~4s with oplocks only.\n\nCollect the target opinfos (each pinned with a reference) while holding\nci-\u003em_lock, then break them after releasing it, matching how\nsmb_grant_oplock() already breaks a conflicting lease using only a\nreference. The reference keeps the opinfo (and its conn and lease)\nalive across the unlocked window, and a close racing the break is\nhandled by the existing OPLOCK_CLOSING state check. Apply the same fix\nto the parent lease break paths."
}
],
"providerMetadata": {
"dateUpdated": "2026-10-26T06:56:24.210Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/868c9038ffd4af39766d087f68c8f543a3f66635"
},
{
"url": "https://git.kernel.org/stable/c/27a9bc968d4ae809a3f5ca2f2b136856ee613cb4"
}
],
"title": "ksmbd: don\u0027t hold ci-\u003em_lock while waiting for a lease break ack",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-98897",
"datePublished": "2026-10-23T11:54:05.872Z",
"dateReserved": "2026-09-25T10:25:14.379Z",
"dateUpdated": "2026-10-26T06:56:24.210Z",
"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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