Executive brief
A vulnerability was identified in the Linux kernel's sound subsystem (ALSA) specifically affecting Gravis UltraSound (GUS) hardware drivers. Under conditions of extreme memory pressure, the system could experience a crash (kernel panic) when attempting to initialize audio controls. This issue primarily impacts system stability and availability for users with specific legacy audio hardware configurations.
Technical details
A vulnerability exists in the sound/isa/gus/gus_pcm.c component of the Linux kernel. The function snd_gf1_pcm_new() calls snd_ctl_new1() to allocate a new control, but fails to verify if the returned pointer is NULL before dereferencing it to set kctl->id.index. This lack of validation leads to a NULL pointer dereference if memory allocation fails. An attacker or a system under heavy load could trigger this condition, resulting in a kernel oops or denial of service. The issue has been resolved by adding a NULL check and returning -ENOMEM upon failure.
Affected products
- Linux Linux kernel 6.1.34 to 6.1.178, 6.3.8 to 6.4, 6.4 and later
Timeline
- 2026-05-28: patched: Initial fix committed to Linux kernel mainline.
- 2026-07-25: disclosed: CVE-2026-64482 published.
References
- https://git.kernel.org/stable/c/465075c6835103821d725c13f8c545898e5f2636
- https://git.kernel.org/stable/c/5e74e5e8cb7cc25f7a89f59abaf3489bf0c6f4a0
- https://git.kernel.org/stable/c/97f6bdf5d5ded2e37f358cacb5a95f1393356604
- https://git.kernel.org/stable/c/c7fa99d30c7a166a5e5db5a585ce7501ff68326b
- https://git.kernel.org/stable/c/eccf8e91266e39f6f15637702a04a1d344833fe2
- https://git.kernel.org/stable/c/fc5d4f27ca1293bc1379ef8fff691c30d9803ca2