CVE-2024-35955

2024-05-2010:15:00

Google

osv.dev

linux kernel

vulnerability resolved

use-after-free

kprobe registration

CVSS3

8.8

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

AI Score

6.6

Confidence

Low

JSON

In the Linux kernel, the following vulnerability has been resolved: kprobes: Fix possible use-after-free issue on kprobe registration When unloading a module, its state is changing MODULE_STATE_LIVE -> MODULE_STATE_GOING -> MODULE_STATE_UNFORMED. Each change will take a time. is_module_text_address() and __module_text_address() works with MODULE_STATE_LIVE and MODULE_STATE_GOING. If we use is_module_text_address() and __module_text_address() separately, there is a chance that the first one is succeeded but the next one is failed because module->state becomes MODULE_STATE_UNFORMED between those operations. In check_kprobe_address_safe(), if the second __module_text_address() is failed, that is ignored because it expected a kernel_text address. But it may have failed simply because module->state has been changed to MODULE_STATE_UNFORMED. In this case, arm_kprobe() will try to modify non-exist module text address (use-after-free). To fix this problem, we should not use separated is_module_text_address() and __module_text_address(), but use only __module_text_address() once and do try_module_get(module) which is only available with MODULE_STATE_LIVE.