CVE-2026-93815 net: au1000: move free_irq out of the close-time spinlocked section
A sleeping function called in atomic context in the au1000 network driver can cause a kernel panic, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-93815?
CVE-2026-93815 is a denial of service vulnerability in Linux, published on 24 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net: au1000: move free_irq out of the close-time spinlocked section
au1000_close() calls free_irq() while aup->lock is still held with spin_lock_irqsave(). free_irq() can sleep because it takes the IRQ descriptor request mutex, so it does not belong inside the close-time spinlocked section.
This was found by our static analysis tool and then confirmed by manual review of the in-tree au1000_close() .ndo_stop path. The reviewed path keeps aup->lock held across the MAC reset, queue stop and free_irq(dev->irq, dev).
A directed runtime validation kept that ndo_stop carrier and the same free_irq(dev->irq, dev) operation under the driver lock. Lockdep reported "BUG: sleeping function called from invalid context" and "Invalid wait context" while free_irq() was taking desc->request_mutex, with au1000_close() and free_irq() on the stack.
Drop aup->lock before freeing the IRQ. The protected close-time work still stops the device and queue before IRQ teardown, but the sleepable IRQ core path now runs outside the spinlocked section.
Which versions are affected by CVE-2026-93815?
How do I fix CVE-2026-93815?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-93815 being exploited?
There is no known exploitation of CVE-2026-93815 in the wild and no public exploit code.
Sources
Also known as AZL-103595, BELL-CVE-2026-93815, DEBIAN-CVE-2026-93815, GHSA-xvh7-3cp2-m6qq, UBUNTU-CVE-2026-93815.