CVE-2022-50558

Description

From CVE.org

In the Linux kernel, the following vulnerability has been resolved: regmap-irq: Use the new num_config_regs property in regmap_add_irq_chip_fwnode Commit faa87ce9196d ("regmap-irq: Introduce config registers for irq types") added the num_config_regs, then commit 9edd4f5aee84 ("regmap-irq: Deprecate type registers and virtual registers") suggested to replace num_type_reg with it. However, regmap_add_irq_chip_fwnode wasn't modified to use the new property. Later on, commit 255a03bb1bb3 ("ASoC: wcd9335: Convert irq chip to config regs") removed the old num_type_reg property from the WCD9335 driver's struct regmap_irq_chip, causing a null pointer dereference in regmap_irq_set_type when it tried to index d->type_buf as it was never allocated in regmap_add_irq_chip_fwnode: [ 39.199374] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [ 39.200006] Call trace: [ 39.200014] regmap_irq_set_type+0x84/0x1c0 [ 39.200026] __irq_set_trigger+0x60/0x1c0 [ 39.200040] __setup_irq+0x2f4/0x78c [ 39.200051] request_threaded_irq+0xe8/0x1a0 Use num_config_regs in regmap_add_irq_chip_fwnode instead of num_type_reg, and fall back to it if num_config_regs isn't defined to maintain backward compatibility.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score4.1N/AN/A
Attack VectorLocalN/AN/A
Attack ComplexityHighN/AN/A
Privileges RequiredHighN/AN/A
User InteractionNoneN/AN/A
ScopeUnchangedN/AN/A
ConfidentialityNoneN/AN/A
Integrity ImpactNoneN/AN/A
Availability ImpactHighN/AN/A

Vector

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

Understanding the Weakness (CWE)

Availability

Technical Impact: DoS: Crash, Exit, or Restart

NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.

Integrity,Confidentiality

Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory

In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.

Frequently Asked Questions

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