CVE-2026-90325
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 bl…
Impact
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.
Affected packages
This record carries no package version data, so it cannot be matched against a dependency list automatically. Read the advisory and compare your version by hand.
References
- NVD record
- CVE.org record
- https://git.kernel.org/stable/c/083b58373463a6e5ee60ecb135269348f68ad7df
- https://git.kernel.org/stable/c/1a267295b1ea6a6477963f3fda84adfecd48fcad
- https://git.kernel.org/stable/c/3d8c3da95c75a4d312e272fc7b4076dd3ba9115c
- https://git.kernel.org/stable/c/5e9220389920f33b6a804d50c548cd0cd1b04634
- https://git.kernel.org/stable/c/7337d012ca3fc3a6a2d1c8e2a19c6d97c38b410d
- https://git.kernel.org/stable/c/b5dae1cd0d8368b4338430ff93403df67f0b8bcc
- https://git.kernel.org/stable/c/d8c872901e6459339374e9eea80aa919176c2ccd