SB20261022161 - Use of Uninitialized Variable in Linux kernel sched

Description

This security bulletin contains information about 1 vulnerability.

1) Use of Uninitialized Variable (CVE-ID: CVE-2026-98584)

CWE-ID: CWE-457 - Use of Uninitialized Variable

CVSSv4: 4.8 [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]

The vulnerability allows a local user to disclose uninitialized kernel stack bytes that may contain sensitive information.

The vulnerability exists due to use of an uninitialized stack variable in em_text_dump() in net/sched/em_text.c when handling traffic-control filter dump requests. A local user can request a dump through "tc filter show" or a raw RTM_GETTFILTER request to receive uninitialized bytes because strscpy() leaves trailing bytes in conf.algo[] unwritten and nla_put_nohdr() copies the entire structure into the netlink response.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/0b160417826d22f24fc31a5b9cfae3b14aa70f76
• https://git.kernel.org/stable/c/9923e1c537f91f3530b52d4efce85f3d9c131bf8
• https://git.kernel.org/stable/c/9c572a83037a7dcd653ba3a9cc468c16b857d0c9