CVE-2025-40048
CVE-2025-40048CVE-2025-40048
Description
In the Linux kernel, the following vulnerability has been resolved:
uio_hv_generic: Let userspace take care of interrupt mask
Remove the logic to set interrupt mask by default in uio_hv_generic
driver as the interrupt mask value is supposed to be controlled
completely by the user space. If the mask bit gets changed
by the driver, concurrently with user mode operating on the ring,
the mask bit may be set when it is supposed to be clear, and the
user-mode driver will miss an interrupt which will cause a hang.
For eg- when the driver sets inbound ring buffer interrupt mask to 1,
the host does not interrupt the guest on the UIO VMBus channel.
However, setting the mask does not prevent the host from putting a
message in the inbound ring buffer. So let’s assume that happens,
the host puts a message into the ring buffer but does not interrupt.
Subsequently, the user space code in the guest sets the inbound ring
buffer interrupt mask to 0, saying “Hey, I’m ready for interrupts”.
User space
Scoring
| CVSS | 7.5 () |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| Last modified | 2026-07-30 |