Live › vulnerability › CVE-2026-98832
Go to dashboardIn the Linux kernel's block cgroup code, a lock helper unconditionally re-enables interrupts even when the caller already had them disabled, which can let a completion softirq re-acquire a held lock. The sources describe this as a deadlock in device-mapper thin provisioning (dm-thin) that lockdep flags, and the fix saves and restores the caller's interrupt state.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.
Systems running a Linux kernel with block cgroups and device-mapper thin pools (dm-thin) are the likely candidates, since the deadlock path runs through dm-thin's pool_map(). Machines without dm-thin or without block cgroup I/O use are unlikely to hit the path. The sources do not say how often the deadlock occurs in practice.
No product ranges from the sources yet.
Each row is the first time that source carried this signal. The analyst’s rows are its own findings.
In the Linux kernel, the following vulnerability has been resolved:
blk-cgroup: save IRQ state in blkg_tryget_closest()
bio_set_dev() associates the bio with a blkg through bio_associate_blkg(). If the blkg lookup misses, blkg_tryget_closest() takes q->queue_lock with spin_lock_irq() and releases it with spin_unlock_irq(), which unconditionally enables local interrupts.
Callers may call bio_set_dev() with interrupts already disabled, e.g. dm-thin's pool_map() does so while holding pool->lock taken with spin_lock_irq(). The nested spin_unlock_irq() then enables interrupts while pool->lock is still held, so an I/O completion softirq can run on the same CPU, re-acquire pool->lock (thin_endio(), or overwrite_endio() -> complete_mapping_preparation()) and deadlock. lockdep reports this as inconsistent SOFTIRQ-ON-W to IN-SOFTIRQ-W usage.
Commit 3a762de55b4e ("block: save irq state in blkg_lookup_create()") fixed the same problem while the lock lived in blkg_lookup_create(), but commit 9327a865e395 ("blk-cgroup: don't nest queue_lock under rcu in blkg_lookup_create()") moved the locking into blkg_tryget_closest() and reverted it to spin_lock_irq().
Save and restore the caller's IRQ state instead.
This page as .md · .json · in your agent: get_signal("CVE-2026-98832")
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