Detections
Analytics
Azure Linux 3.0 Security Update: kernel (CVE-2025-21943)
medium Nessus Plugin ID 235236
Synopsis
The remote Azure Linux host is missing one or more security updates.Description
The version of kernel 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-2025-21943 advisory.- In the Linux kernel, the following vulnerability has been resolved: gpio: aggregator: protect driver attr handlers against module unload Both new_device_store and delete_device_store touch module global resources (e.g. gpio_aggregator_lock). To prevent race conditions with module unload, a reference needs to be held.
Add try_module_get() in these handlers. For new_device_store, this eliminates what appears to be the most dangerous scenario: if an id is allocated from gpio_aggregator_idr but platform_device_register has not yet been called or completed, a concurrent module unload could fail to unregister/delete the device, leaving behind a dangling platform device/GPIO forwarder. This can result in various issues. The following simple reproducer demonstrates these problems: #!/bin/bash while :; do # note: whether 'gpiochip0 0' exists or not does not matter. echo 'gpiochip0 0' > /sys/bus/platform/drivers/gpio-aggregator/new_device done & while :; do modprobe gpio-aggregator modprobe -r gpio-aggregator done & wait Starting with the following warning, several kinds of warnings will appear and the system May become unstable: ------------[ cut here ]------------ list_del corruption, ffff888103e2e980->next is LIST_POISON1 (dead000000000100) WARNING: CPU: 1 PID: 1327 at lib/list_debug.c:56 __list_del_entry_valid_or_report+0xa3/0x120 [...] RIP:
0010:__list_del_entry_valid_or_report+0xa3/0x120 [...] Call Trace: <TASK> ?
__list_del_entry_valid_or_report+0xa3/0x120 ? __warn.cold+0x93/0xf2 ?
__list_del_entry_valid_or_report+0xa3/0x120 ? report_bug+0xe6/0x170 ? __irq_work_queue_local+0x39/0xe0 ? handle_bug+0x58/0x90 ? exc_invalid_op+0x13/0x60 ? asm_exc_invalid_op+0x16/0x20 ?
__list_del_entry_valid_or_report+0xa3/0x120 gpiod_remove_lookup_table+0x22/0x60 new_device_store+0x315/0x350 [gpio_aggregator] kernfs_fop_write_iter+0x137/0x1f0 vfs_write+0x262/0x430 ksys_write+0x60/0xd0 do_syscall_64+0x6c/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e [...] </TASK> ---[ end trace 0000000000000000 ]--- (CVE-2025-21943)
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
Plugin Details
Severity: Medium
ID: 235236
File Name: azure_linux_CVE-2025-21943.nasl
Version: 1.1
Type: local
Published: 5/6/2025
Updated: 5/6/2025
Supported Sensors: Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 5.1
CVSS v2
Risk Factor: Low
Base Score: 3.8
Temporal Score: 2.8
Vector: CVSS2#AV:L/AC:H/Au:S/C:N/I:N/A:C
CVSS Score Source: CVE-2025-21943
CVSS v3
Risk Factor: Medium
Base Score: 4.7
Temporal Score: 4.1
Vector: CVSS:3.0/AV:L/AC:H/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:kernel-debuginfo, p-cpe:/a:microsoft:azure_linux:kernel-devel, p-cpe:/a:microsoft:azure_linux:kernel-drivers-gpu, p-cpe:/a:microsoft:azure_linux:kernel-dtb, p-cpe:/a:microsoft:azure_linux:python3-perf, p-cpe:/a:microsoft:azure_linux:kernel-docs, x-cpe:/o:microsoft:azure_linux, p-cpe:/a:microsoft:azure_linux:kernel, p-cpe:/a:microsoft:azure_linux:kernel-drivers-sound, p-cpe:/a:microsoft:azure_linux:bpftool, p-cpe:/a:microsoft:azure_linux:kernel-drivers-intree-amdgpu, p-cpe:/a:microsoft:azure_linux:kernel-drivers-accessibility, p-cpe:/a:microsoft:azure_linux:kernel-tools
Required KB Items: Host/local_checks_enabled, Host/AzureLinux/release, Host/AzureLinux/rpm-list, Host/cpu
Exploit Ease: No known exploits are available
Patch Publication Date: 5/1/2025
Vulnerability Publication Date: 4/1/2025
Reference Information
CVE: CVE-2025-21943