SB2026061025 - Use of uninitialized resource in Linux kernel io_uring

Description

This security bulletin contains information about 1 vulnerability.

1) Use of uninitialized resource (CVE-ID: CVE-2026-46315)

CWE-ID: CWE-908 - Use of Uninitialized Resource

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to disclose sensitive information.

The vulnerability exists due to uninitialized memory usage in io_uring IORING_OP_WAITID result handling when copying waitid result data to userspace. A local user can trigger a wait operation that completes without reporting a child event to disclose sensitive information.

The issue occurs because stale bytes from reused io_kiocb command storage may be copied to userspace siginfo when no child event information is written.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/4d2a0de611ab60d02fc768ae0cd5918b16bd5474
• https://git.kernel.org/stable/c/93d93f5f8da791e98159795c6ef683f45bd95d13
• https://git.kernel.org/stable/c/954518e5a4a5efc5033253f6e36fc7b9f98363a3
• https://git.kernel.org/stable/c/b737c6612c60c23b40a9f31749b99e6f61943847