CVE-2024-56600 in Linux
Summary
by MITRE • 12/27/2024
In the Linux kernel, the following vulnerability has been resolved:
net: inet6: do not leave a dangling sk pointer in inet6_create()
sock_init_data() attaches the allocated sk pointer to the provided sock object. If inet6_create() fails later, the sk object is released, but the sock object retains the dangling sk pointer, which may cause use-after-free later.
Clear the sock sk pointer on error.
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Analysis
by VulDB Data Team • 01/05/2026
This vulnerability resides within the Linux kernel's networking subsystem, specifically in the inet6_create() function that handles IPv6 socket creation. The issue represents a classic use-after-free condition that can occur during socket allocation and initialization processes. When a socket object is allocated and initialized, the sock_init_data() function properly associates the socket kernel pointer with the socket object. However, if subsequent operations within inet6_create() fail, the allocated socket kernel pointer gets freed while the socket object itself remains in memory with a dangling reference to the now-freed memory location. This creates a scenario where any subsequent access to the socket object's sk pointer could result in accessing freed memory, leading to potential system instability or exploitation opportunities.
The technical flaw manifests in the socket lifecycle management where proper error handling fails to clear the socket pointer reference after allocation failure. This particular vulnerability operates at the kernel level within the networking stack, making it particularly dangerous as it can be exploited to gain unauthorized access to system resources or cause system crashes. The issue directly relates to CWE-415 which describes double free errors and CWE-416 which covers use-after-free conditions. From an operational perspective, this vulnerability represents a significant security risk as it could allow attackers to manipulate kernel memory structures through crafted network traffic, potentially leading to privilege escalation or denial of service conditions.
The operational impact of CVE-2024-56600 extends beyond simple memory corruption as it affects the fundamental socket creation mechanism in IPv6 networking. Attackers could potentially exploit this vulnerability by initiating multiple socket creation requests that trigger the error path, leading to a controlled use-after-free condition. This condition could be leveraged to execute arbitrary code in kernel space or cause system crashes that result in denial of service. The vulnerability aligns with ATT&CK technique T1068 which covers local privilege escalation through kernel exploits, and T1499 which covers network denial of service attacks. The vulnerability affects all Linux kernel versions that implement the problematic inet6_create() function, particularly those supporting IPv6 networking capabilities.
Mitigation strategies for this vulnerability should focus on applying the official kernel patches that clear the socket sk pointer on error conditions as specified in the fix. System administrators should prioritize updating their kernel versions to include the patched implementation that properly handles socket pointer cleanup during error scenarios. Additionally, network monitoring solutions should be configured to detect unusual socket creation patterns that might indicate exploitation attempts. The fix implements proper error handling that ensures socket pointer references are cleared when allocation failures occur, preventing the dangling pointer scenario. Organizations should also consider implementing kernel hardening measures such as stack canaries, kernel address space layout randomization, and other exploit mitigation techniques to reduce the potential impact if exploitation were to occur despite the patch. Regular kernel updates and security auditing processes should be maintained to ensure all systems remain protected against similar vulnerabilities in the networking subsystem.