CVE-2026-46088

About vulnerability

In the Linux kernel, the following vulnerability has been resolved:

ALSA: control: Validate buf_len before strnlen() in snd_ctl_elem_init_enum_names()

snd_ctl_elem_init_enum_names() advances pointer p through the names buffer while decrementing buf_len. If buf_len reaches zero but items remain, the next iteration calls strnlen(p, 0).

While strnlen(p, 0) returns 0 and would hit the existing name_len == 0 error path, CONFIG_FORTIFY_SOURCE’s fortified strnlen() first checks maxlen against __builtin_dynamic_object_size(). When Clang loses track of p’s object size inside the loop, this triggers a BRK exception panic before the return value is examined.

Add a buf_len == 0 guard at the loop entry to prevent calling fortified strnlen() on an exhausted buffer.

Found by kernel fuzz testing through Xiaomi Smartphone.

Affected product:

AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Debian 10 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS

Affected packages:

kernel @ 4.18.0 (+16 more)

Live-patch status from KernelCare for each operating system.