CVE-2026-64482 in Linux
Summary
by MITRE • 07/25/2026
In the Linux kernel, the following vulnerability has been resolved:
ALSA: gus: check snd_ctl_new1() return value
snd_ctl_new1() can return NULL when memory allocation fails. snd_gf1_pcm_volume_control() does not check the return value before dereferencing kctl->id.index, which can lead to a NULL pointer dereference.
Add a NULL check after snd_ctl_new1() and return -ENOMEM if it fails.
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Analysis
by VulDB Data Team • 07/25/2026
This vulnerability resides within the Advanced Linux Sound Architecture subsystem of the Linux kernel specifically affecting the gus audio driver implementation. The flaw represents a classic null pointer dereference issue that occurs during the initialization of control interfaces for sound hardware devices. The vulnerability manifests when the system attempts to allocate memory for new control elements through the snd_ctl_new1() function, which may fail under memory pressure conditions or resource constraints. When this allocation fails and returns NULL, subsequent code execution attempts to access member variables of the null pointer without proper validation.
The technical implementation flaw stems from insufficient error handling in the snd_gf1_pcm_volume_control() function which directly dereferences the kctl->id.index field without verifying whether the preceding memory allocation succeeded. This pattern violates fundamental defensive programming practices and creates a potential crash scenario that can be exploited by malicious actors or inadvertently triggered by system resource exhaustion. The vulnerability specifically affects the gus audio driver implementation where the kernel attempts to create control interfaces for General MIDI sound devices, particularly those using the Gravis Ultrasound architecture.
The operational impact of this vulnerability extends beyond simple system instability as it represents a potential denial of service condition that could be exploited in kernel space. When the NULL pointer dereference occurs, the kernel will likely crash or panic, resulting in system instability and potential data loss for users running audio-intensive applications. This issue is particularly concerning in embedded systems or server environments where audio subsystems may be actively utilized. The vulnerability affects systems using the gus audio driver specifically and could potentially impact any application relying on proper kernel sound subsystem functionality.
Mitigation strategies should focus on implementing proper error handling patterns and ensuring all kernel memory allocation functions are validated before subsequent dereference operations. The fix requires adding a NULL return value check immediately after the snd_ctl_new1() call and returning the appropriate -ENOMEM error code when allocation fails. This approach aligns with common kernel development practices and follows established security guidelines for memory management in kernel space. Organizations should ensure their systems are updated with patches addressing this vulnerability, particularly those running audio-intensive workloads or embedded systems where reliability is critical. The fix demonstrates proper adherence to the principle of least privilege and defensive programming techniques that prevent unauthorized access patterns within kernel memory structures.
This vulnerability classification corresponds to CWE-476 Null Pointer Dereference which is commonly exploited in kernel space due to the privileged execution context. From an attack perspective, this represents a low-complexity, high-impact issue that could be leveraged for denial of service attacks against systems running affected kernel versions. The vulnerability also aligns with ATT&CK technique T1068, which involves local privilege escalation through kernel vulnerabilities, though in this case it manifests as a denial of service rather than privilege elevation. Proper system hardening and memory management practices should be implemented to prevent similar issues in other kernel subsystems where similar patterns of memory allocation and dereference operations occur.