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no cvss —

CVE-2026-98897 json

ksmbd: don't hold ci->m_lock while waiting for a lease break ack

published 19d ago modified 17d ago also EUVD-2026-108853

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 8%
public exploits
0
none known

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.

Patch / fix

  • Linux Linux 6.7, 7.2
  • linux Debian 14 7.2.6-1

debian advisories DEBIAN-CVE-2026-98897

  • linux Ubuntu 26.04 LTS 7.0.0-42.42
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1016.17
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1016.18
  • linux-ibm Ubuntu 26.04 LTS 7.0.0-1017.17
  • linux-riscv Ubuntu 26.04 LTS 7.0.0-42.42.1
  • linux-oracle Ubuntu 26.04 LTS 7.0.0-1015.16
  • linux-hwe-7.0 Ubuntu 24.04 LTS 7.0.0-42.42~24.04.1
  • linux-oem-7.0 Ubuntu 26.04 LTS 7.0.0-1017.17

ubuntu advisories UBUNTU-CVE-2026-98897

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-98897 updated cvss 4.3

kernel: ksmbd: don't hold ci->m_lock while waiting for a lease break ack

  • Red Hat Enterprise Linux 10 kernel
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-11).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.