Detections
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Azure Linux 3.0 Security Update: hyperv-daemons (CVE-2024-26935)

medium Nessus Plugin ID 295782

Synopsis

The remote Azure Linux host is missing one or more security updates.

Description

The version of hyperv-daemons installed on the remote Azure Linux 3.0 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the CVE-2024-26935 advisory.

 - In the Linux kernel, the following vulnerability has been resolved: scsi: core: Fix unremoved procfs host directory regression Commit fc663711b944 (scsi: core: Remove the /proc/scsi/${proc_name} directory earlier) fixed a bug related to modules loading/unloading, by adding a call to scsi_proc_hostdir_rm() on scsi_remove_host(). But that led to a potential duplicate call to the hostdir_rm() routine, since it's also called from scsi_host_dev_release(). That triggered a regression report, which was then fixed by commit be03df3d4bfe (scsi: core: Fix a procfs host directory removal regression). The fix just dropped the hostdir_rm() call from dev_release(). But it happens that this proc directory is created on scsi_host_alloc(), and that function pairs with scsi_host_dev_release(), while scsi_remove_host() pairs with scsi_add_host(). In other words, it seems the reason for removing the proc directory on dev_release() was meant to cover cases in which a SCSI host structure was allocated, but the call to scsi_add_host() didn't happen. And that pattern happens to exist in some error paths, for example. Syzkaller causes that by using USB raw gadget device, error'ing on usb-storage driver, at usb_stor_probe2(). By checking that path, we can see that the BadDevice label leads to a scsi_host_put() after a SCSI host allocation, but there's no call to scsi_add_host() in such path. That leads to messages like this in dmesg (and a leak of the SCSI host proc structure): usb-storage 4-1:87.51: USB Mass Storage device detected proc_dir_entry 'scsi/usb-storage' already registered WARNING: CPU: 1 PID: 3519 at fs/proc/generic.c:377 proc_register+0x347/0x4e0 fs/proc/generic.c:376 The proper fix seems to still call scsi_proc_hostdir_rm() on dev_release(), but guard that with the state check for SHOST_CREATED; there is even a comment in scsi_host_dev_release() detailing that: such conditional is meant for cases where the SCSI host was allocated but there was no calls to {add,remove}_host(), like the usb-storage case. This is what we propose here and with that, the error path of usb-storage does not trigger the warning anymore.
 (CVE-2024-26935)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

See Also

https://nvd.nist.gov/vuln/detail/CVE-2024-26935

Plugin Details

Severity: Medium

ID: 295782

File Name: azure_linux_CVE-2024-26935.nasl

Version: 1.1

Type: local

Published: 1/22/2026

Updated: 1/22/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

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

CVSS Score Source: CVE-2024-26935

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

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

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

Vulnerability Information

CPE: p-cpe:/a:microsoft:azure_linux:hypervvssd, p-cpe:/a:microsoft:azure_linux:hyperv-tools, p-cpe:/a:microsoft:azure_linux:hyperv-daemons-debuginfo, p-cpe:/a:microsoft:azure_linux:hyperv-daemons-license, x-cpe:/o:microsoft:azure_linux, p-cpe:/a:microsoft:azure_linux:hypervfcopyd, p-cpe:/a:microsoft:azure_linux:hypervkvpd, p-cpe:/a:microsoft:azure_linux:hyperv-daemons

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/AzureLinux/release, Host/AzureLinux/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 9/10/2024

Vulnerability Publication Date: 4/9/2024

Reference Information

CVE: CVE-2024-26935