Improper Initialization Affecting kernel-rt-debug-modules package, versions *

Note: Versions mentioned in the description apply only to the upstream kernel-rt-debug-modules package and not the kernel-rt-debug-modules package as distributed by Centos. See How to fix? for Centos:8 relevant fixed versions and status.

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

sched/smt: Fix unbalance sched_smt_present dec/inc

I got the following warn report while doing stress test:

jump label: negative count! WARNING: CPU: 3 PID: 38 at kernel/jump_label.c:263 static_key_slow_try_dec+0x9d/0xb0 Call Trace: <TASK> __static_key_slow_dec_cpuslocked+0x16/0x70 sched_cpu_deactivate+0x26e/0x2a0 cpuhp_invoke_callback+0x3ad/0x10d0 cpuhp_thread_fun+0x3f5/0x680 smpboot_thread_fn+0x56d/0x8d0 kthread+0x309/0x400 ret_from_fork+0x41/0x70 ret_from_fork_asm+0x1b/0x30 </TASK>

Because when cpuset_cpu_inactive() fails in sched_cpu_deactivate(), the cpu offline failed, but sched_smt_present is decremented before calling sched_cpu_deactivate(), it leads to unbalanced dec/inc, so fix it by incrementing sched_smt_present in the error path.

• https://access.redhat.com/security/cve/CVE-2024-44958
• https://git.kernel.org/stable/c/2a3548c7ef2e135aee40e7e5e44e7d11b893e7c4
• https://git.kernel.org/stable/c/2cf7665efe451e48d27953e6b5bc627d518c902b
• https://git.kernel.org/stable/c/65727331b60197b742089855ac09464c22b96f66
• https://git.kernel.org/stable/c/d0c87a3c6be10a57aa3463c32c3fc6b2a47c3dab
• https://git.kernel.org/stable/c/e22f910a26cc2a3ac9c66b8e935ef2a7dd881117