In the Linux kernel, a critical vulnerability - assigned as CVE-2022-49731 - has been identified and resolved, significantly improving the security of the core operating system. This particular vulnerability involves the function ata_host_alloc_pinfo() in the libata-core, which handles the allocation of information for ATA ports in a host. If not addressed, this could lead to a kernel crash resulting in system instability.

Code Snippet

Before the vulnerability fix, if the 'ppi' parameter of ata_host_alloc_pinfo() pointed to an array starting with a NULL pointer, there would be a kernel oops due to the 'pi' local variable not getting reassigned.

static struct ata_host *ata_host_alloc_pinfo(struct device *dev,
					      const struct ata_port_info * const * ppi,
					      int n_ports)
{
	struct ata_host *host;
	struct ata_port *ap;
	void *start;
	int i, j;

    //...rest of the code...
}

The vulnerability has been resolved by initializing the 'pi' variable to '&ata_dummy_port_info'. This simple change prevents the possible kernel crash and enhances the overall stability of the Linux operating system.

static struct ata_host *ata_host_alloc_pinfo(struct device *dev,
					      const struct ata_port_info * const * ppi,
					      int n_ports)
{
	struct ata_host *host;
	struct ata_port *ap;
	void *start;
	int i, j;

	// Initialize 'pi' variable to fix kernel crash vulnerability
	static const struct ata_port_info *pi = &ata_dummy_port_info;
    
    //...rest of the code...
}

Original References

This vulnerability was discovered by the Linux Verification Center (linuxtesting.org) using the SVACE (Static Vulnerability and Code Exploration) static analysis tool. For further information on this vulnerability and its resolution, please refer to the following links:

1. Linux Verification Center
2. SVACE Static Analysis Tool
3. Linux Kernel Mailing List: Libata-core fix

Exploit Details

An attacker may exploit this vulnerability by inducing a condition in which the 'ppi' parameter points to an array starting with a NULL pointer, leading to a kernel crash that causes system instability. This bug could grant the attacker the ability to disrupt core system functionality, deny access to resources, or potentially execute arbitrary code through other related vulnerabilities.

However, with the recent patch applied to the Linux kernel, the risk of successful exploitation is significantly mitigated. It is highly recommended that users ensure their Linux systems are updated to the latest kernel version to protect against such vulnerabilities.

In conclusion, CVE-2022-49731 is a noteworthy vulnerability in the Linux kernel that has now been addressed. By staying informed and up-to-date with patches and security measures, users can continue to enjoy the numerous benefits offered by the Linux operating system while maintaining the highest levels of security and stability.

Timeline

Published on: 02/26/2025 07:01:48 UTC
Last modified on: 03/07/2025 20:44:17 UTC