CVE-2026-64430
Published: July 29, 2026Last modified: August 14, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: NTB: epf: Avoid calling pci_irq_vector() from hardirq context ntb_epf_vec_isr() calls pci_irq_vector() in hardirq context to derive the vector number. pci_irq_vector() calls msi_get_virq() that takes a mutex and can therefore trigger "scheduling while atomic" splats: BUG: scheduling while atomic: kworker/u33:0/55/0x00010001 ... Call trace: ... schedule+0x38/0x110 schedule_preempt_disabled+0x28/0x50 __mutex_lock.constprop.0+0x848/0x908 __mutex_lock_slowpath+0x18/0x30 mutex_lock+0x4c/0x60 msi_domain_get_virq+0xe8/0x138 pci_irq_vector+0x2c/0x60 ntb_epf_vec_isr+0x28/0x120 [ntb_hw_epf] __handle_irq_event_percpu+0x70/0x3a8 handle_irq_event+0x48/0x100 handle_edge_irq+0x100/0x1c8 ... Cache the Linux IRQ number for vector 0 when vectors are allocated and use it as a base in the ISR. Running the ISR in a threaded IRQ handler would also avoid the problem, but that would be unnecessary here.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.5 |
| Attack Vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | NONE |
| Integrity impact | NONE |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Fixed (6.1.182-r0) |
| 25 LTS | linux-lts | Fixed (6.12.103-r0) | |
| Stream | linux-lts | Fixed (6.18.43-r0) |
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