Executive brief
A vulnerability in the Linux kernel's Non-Transparent Bridge (NTB) driver could cause the system to crash or become unstable. This occurs when the system attempts to perform certain internal hardware management tasks at the same time it is handling high-priority hardware signals. While this primarily affects system stability and availability, it could be used to cause a denial-of-service on affected machines.
Technical details
A 'scheduling while atomic' bug exists in the Linux kernel NTB EPF driver (drivers/ntb/hw/epf/ntb_hw_epf.c). The function ntb_epf_vec_isr() calls pci_irq_vector() within a hardirq context. Because pci_irq_vector() eventually calls msi_domain_get_virq(), which attempts to acquire a mutex, the kernel may attempt to sleep or reschedule while in an atomic state. This violation of kernel locking primitives leads to kernel panics or 'splats'. The fix involves caching the IRQ base during initialization so it can be accessed in the ISR without calling blocking functions.
Affected products
- Linux Linux 5.12 to 6.13
Timeline
- 2026-03-04: other: Patch authored
- 2026-07-25: disclosed: CVE published
References
- https://git.kernel.org/stable/c/174a97f21bf9c54fa37ec0f321692e862ea130a3
- https://git.kernel.org/stable/c/1dba8444ac0100133d72374634f6d7451fff1ccc
- https://git.kernel.org/stable/c/33bba331a4a5fee8b6026fe72eca13cceeec1b7b
- https://git.kernel.org/stable/c/4dcddc1c794d1c65eda68f1f8dd04a0fecc0870f
- https://git.kernel.org/stable/c/6350df503897d57c5634f71b0767d48c3b837583
- https://git.kernel.org/stable/c/aff271b12a1eb8c8b3da19223ae1a6abe1e8168b
- https://git.kernel.org/stable/c/f71e8d9875069fa73e335f63f02ec6e52e3aaa51