Linux Kernel up to 6.6.22/6.7.10 qcom pmic_glink_altmode null pointer dereference
CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
---|---|---|
4.6 | $0-$5k | 0.00 |
A vulnerability has been found in Linux Kernel up to 6.6.22/6.7.10 and classified as critical. Affected by this vulnerability is the function pmic_glink_altmode
of the component qcom. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. The summary by CVE is:
In the Linux kernel, the following vulnerability has been resolved: soc: qcom: pmic_glink_altmode: fix drm bridge use-after-free A recent DRM series purporting to simplify support for "transparent bridges" and handling of probe deferrals ironically exposed a use-after-free issue on pmic_glink_altmode probe deferral. This has manifested itself as the display subsystem occasionally failing to initialise and NULL-pointer dereferences during boot of machines like the Lenovo ThinkPad X13s. Specifically, the dp-hpd bridge is currently registered before all resources have been acquired which means that it can also be deregistered on probe deferrals. In the meantime there is a race window where the new aux bridge driver (or PHY driver previously) may have looked up the dp-hpd bridge and stored a (non-reference-counted) pointer to the bridge which is about to be deallocated. When the display controller is later initialised, this triggers a use-after-free when attaching the bridges: dp -> aux -> dp-hpd (freed) which may, for example, result in the freed bridge failing to attach: [drm:drm_bridge_attach [drm]] *ERROR* failed to attach bridge /soc@0/phy@88eb000 to encoder TMDS-31: -16 or a NULL-pointer dereference: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 ... Call trace: drm_bridge_attach+0x70/0x1a8 [drm] drm_aux_bridge_attach+0x24/0x38 [aux_bridge] drm_bridge_attach+0x80/0x1a8 [drm] dp_bridge_init+0xa8/0x15c [msm] msm_dp_modeset_init+0x28/0xc4 [msm] The DRM bridge implementation is clearly fragile and implicitly built on the assumption that bridges may never go away. In this case, the fix is to move the bridge registration in the pmic_glink_altmode driver to after all resources have been looked up. Incidentally, with the new dp-hpd bridge implementation, which registers child devices, this is also a requirement due to a long-standing issue in driver core that can otherwise lead to a probe deferral loop (see commit fbc35b45f9f6 ("Add documentation on meaning of -EPROBE_DEFER")). [DB: slightly fixed commit message by adding the word 'commit']
The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2024-26909 since 02/19/2024. The exploitation appears to be difficult. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/17/2024).
Upgrading to version 6.6.23, 6.7.11 or 6.8 eliminates this vulnerability. Applying the patch 2bbd65c6ca56/ef45aa2841e1/b979f2d50a09 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.
Product
Type
Vendor
Name
Version
- 6.6.0
- 6.6.1
- 6.6.2
- 6.6.3
- 6.6.4
- 6.6.5
- 6.6.6
- 6.6.7
- 6.6.8
- 6.6.9
- 6.6.10
- 6.6.11
- 6.6.12
- 6.6.13
- 6.6.14
- 6.6.15
- 6.6.16
- 6.6.17
- 6.6.18
- 6.6.19
- 6.6.20
- 6.6.21
- 6.6.22
- 6.7.0
- 6.7.1
- 6.7.2
- 6.7.3
- 6.7.4
- 6.7.5
- 6.7.6
- 6.7.7
- 6.7.8
- 6.7.9
- 6.7.10
License
CPE 2.3
CPE 2.2
CVSSv4
VulDB CVSS-B Score: 🔒VulDB CVSS-BT Score: 🔒
VulDB Vector: 🔒
VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 4.8VulDB Meta Temp Score: 4.6
VulDB Base Score: 4.8
VulDB Temp Score: 4.6
VulDB Vector: 🔒
VulDB Reliability: 🔍
CVSSv2
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍
Exploiting
Class: Null pointer dereferenceCWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒
Local: No
Remote: Partially
Availability: 🔒
Status: Not defined
EPSS Score: 🔒
EPSS Percentile: 🔒
Price Prediction: 🔍
Current Price Estimation: 🔒
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Threat Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: UpgradeStatus: 🔍
0-Day Time: 🔒
Upgrade: Kernel 6.6.23/6.7.11/6.8
Patch: 2bbd65c6ca56/ef45aa2841e1/b979f2d50a09
Timeline
02/19/2024 CVE reserved04/17/2024 Advisory disclosed
04/17/2024 VulDB entry created
04/17/2024 VulDB entry last update
Sources
Vendor: kernel.orgAdvisory: git.kernel.org
Status: Confirmed
CVE: CVE-2024-26909 (🔒)
Entry
Created: 04/17/2024 13:32Changes: 04/17/2024 13:32 (58)
Complete: 🔍
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