CVE-2026-90325

CVE CVE-2026-90325EUVD EUVD-2026-81986Published 2026-09-17T16:08:40.000ZLast changed 2026-09-18T17:54:37.000ZCVSS 7.8

What the advisory describes

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.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

Linux — Linux patch: 6.12.110; bfe46d2efe46c5c952f982e2ca94fe2ec5e58e2a <083b58373463a6e5ee60ecb135269348f68ad7df; f1c006f1c6850c14040f8337753a63119bba39b9 <1a267295b1ea6a6477963f3fda84adfecd48fcad; f1c006f1c6850c14040f8337753a63119bba39b9 <3d8c3da95c75a4d312e272fc7b4076dd3ba9115c; patch: 6.2.4; patch: 6.6.157; 6.3; f1c006f1c6850c14040f8337753a63119bba39b9 <d8c872901e6459339374e9eea80aa919176c2ccd; f1c006f1c6850c14040f8337753a63119bba39b9 <7337d012ca3fc3a6a2d1c8e2a19c6d97c38b410d; patch: 7.2.6; 81c1188905f88b77743d1fdeeedfc8cb7b67787d <b5dae1cd0d8368b4338430ff93403df67f0b8bcc; 6.1.16 <6.1.17; patch: 6.1.17; patch: 6.18.52; 6.2.3 <6.2.4; patch: 0; f1c006f1c6850c14040f8337753a63119bba39b9 <5e9220389920f33b6a804d50c548cd0cd1b04634; patch: 7.3-rc1

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

Linux — Linux

Does this concern one of your customers?

This page cannot answer that — it does not know your estate. Whoever has recorded their environments gets the answer the morning after publication, together with a paragraph they can forward to the customer unedited.

Try it for 28 days

Patchlage reports hits and suspected hits. About everything else this system says nothing — neither this page nor the situation report ever claims that an estate is safe.