Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
Low
Attack Vector
Local
0

CVE-2024-46693

Disclosure Date: September 13, 2024
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

In the Linux kernel, the following vulnerability has been resolved:

soc: qcom: pmic_glink: Fix race during initialization

As pointed out by Stephen Boyd it is possible that during initialization
of the pmic_glink child drivers, the protection-domain notifiers fires,
and the associated work is scheduled, before the client registration
returns and as a result the local “client” pointer has been initialized.

The outcome of this is a NULL pointer dereference as the “client”
pointer is blindly dereferenced.

Timeline provided by Stephen:
CPU0 CPU1


ucsi->client = NULL;
devm_pmic_glink_register_client()
client->pdr_notify(client->priv, pg->client_state)
pmic_glink_ucsi_pdr_notify()

schedule_work(&ucsi->register_work)
<schedule away>
                                pmic_glink_ucsi_register()
                                 ucsi_register()
                                  pmic_glink_ucsi_read_version()
                                   pmic_glink_ucsi_read()
                                    pmic_glink_ucsi_read()
                                     pmic_glink_send(ucsi->client)
                                     <client is NULL BAD>

ucsi->client = client // Too late!

This code is identical across the altmode, battery manager and usci
child drivers.

Resolve this by splitting the allocation of the “client” object and the
registration thereof into two operations.

This only happens if the protection domain registry is populated at the
time of registration, which by the introduction of commit ‘1ebcde047c54
(“soc: qcom: add pd-mapper implementation”)’ became much more likely.

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CVSS V3 Severity and Metrics
Base Score:
4.7 Medium
Impact Score:
3.6
Exploitability Score:
1
Vector:
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector (AV):
Local
Attack Complexity (AC):
High
Privileges Required (PR):
Low
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
None
Integrity (I):
None
Availability (A):
High

General Information

Additional Info

Technical Analysis