Detections
Analytics

Echo: linux: security update to 6.1.158-1

high Tenable Cloud Security Plugin ID 462885

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

 - 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 code then calls pread() to wait for an interrupt.
 Then one of two things happens: * The host never sends another message. So the pread() waits forever. *
 The host does send another message. But because there’s already a message in the ring buffer, it doesn’t
 generate an interrupt. This is the correct behavior, because the host should only send an interrupt when
 the inbound ring buffer transitions from empty to not-empty. Adding an additional message to a ring buffer
 that is not empty is not supposed to generate an interrupt on the guest. Since the guest is waiting in
 pread() and not removing messages from the ring buffer, the pread() waits forever. This could be easily
 reproduced in hv_fcopy_uio_daemon if we delay setting interrupt mask to 0. Similarly if
 hv_uio_channel_cb() sets the interrupt_mask to 1, there’s a race condition. Once user space empties the
 inbound ring buffer, but before user space sets interrupt_mask to 0, the host could put another message in
 the ring buffer but it wouldn’t interrupt. Then the next pread() would hang. Fix these by removing all
 instances where interrupt_mask is changed, while keeping the one in set_event() unchanged to enable
 userspace control the interrupt mask by writing 0/1 to /dev/uioX. (CVE-2025-40048)

Solution

Update the linux library and its related packages to version 6.1.158-1 or later.

See Also

https://advisory.echohq.com/cve/CVE-2025-40048

Plugin Details

Severity: High

ID: 462885

Version: Revision 1.1

Type: Local

Published: 10/2/2026

Updated: 10/2/2026

Risk Information

VPR

Risk Factor: Medium

Score: 5.7

Percentile: 96.81

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

CVSS Score Source: CVE-2025-40048

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 10/30/2025

Vulnerability Publication Date: 10/23/2025

Reference Information

CVE: CVE-2025-40048