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TI-2026-61366 Aliases CVE-2026-90325GHSA-5ghq-73f5-5j56

blk-cgroup: skip dying blkg in blkcg_activate_policy()

Priority LOW 33Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 5 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: skip dying blkg in blkcg_activate_policy() When switching IO schedulers on a block device, blkcg_activate_policy() can race with concurrent blkcg deletion, leading to a use-after-free in rcu_accelerate_cbs. T1: T2: blkg_destroy kill(&blkg->refcnt) // blkg->refcnt=1->0 blkg_release // call_rcu(__blkg_release) ... blkg_free_workfn ->pd_free_fn(pd) elv_iosched_store elevator_switch ... iterate blkg list blkg_get(blkg) // blkg->refcnt=0->1 list_del_init(&blkg->q_node) blkg_put(pinned_blkg) // blkg->refcnt=1->0 blkg_release // call_rcu again rcu_accelerate_cbs // uaf Fix this by checking hlist_unhashed(&blkg->blkcg_node) before getting a reference to the blkg. This is the same check used in blkg_destroy() to detect if a blkg has already been destroyed. If the blkg is already unhashed, skip processing it since it's being destroyed.

Why it matters now

EPSS 0.00164 5th percentileScored 2026-11-07
Fix Partial Linux (Linux): 6.1.17, 6.2.4, 6.6.157 +4Red Hat: 5 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux6.1.16 to before 6.1.17; 6.2.3 to before 6.2.46.1.17, 6.2.4Patch availableCNA
LinuxLinux6.3 and later6.1.17, 6.2.4, 6.6.157, 6.12.110, 6.18.52, 7.2.6, 7.3Patch availableCNA
  • Linux VendorLinux Affected 6.1.16 to before 6.1.17; 6.2.3 to before 6.2.4 Fixed in 6.1.17, 6.2.4 Patch available CNA
  • Linux VendorLinux Affected 6.3 and later Fixed in 6.1.17, 6.2.4, 6.6.157, 6.12.110, 6.18.52, 7.2.6, 7.3 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*——Linux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions — — ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 6.1.17, 6.2.4
  • Fix · CNA Linux (Linux) Fixed in 6.1.17, 6.2.4, 6.6.157, 6.12.110, 6.18.52, 7.2.6, 7.3

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 5AffectedNo fix yet: Fix deferred
Not affected: 4 products
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9
  • Red Hat OpenShift Container Platform 4

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-90325
  2. 2026-10-03 Alias added: GHSA-5ghq-73f5-5j56
  3. 2026-10-15 Affected versions changed · Red Hat
  4. 2026-10-15 CVSS score added · Red Hat
  5. 2026-10-19 Fix available: Linux/[email protected] · CNA
  6. 2026-10-24 Affected versions changed · Red Hat
  7. 2026-10-24 CVSS score changed · Red Hat
  8. 2026-10-29 Affected versions changed · Red Hat
  9. 2026-11-06 Affected versions changed · Red Hat

References

Other 7

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
See all 21727 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences