published September 3, 2026
In the Linux kernel, the following vulnerability has been resolved:
x86/mce: Set up the polling timer before CMCI discovery
I hit the following on one of my machines:
mce: CPU0 BANK15 CMCI inherited storm
------------[ cut here ]------------
ODEBUG: assert_init not available (active state 0) object: (____ptrval____) object type: timer_list hint: 0x0
WARNING: lib/debugobjects.c:632 at debug_object_assert_init+0x178/0x230, CPU#0: swapper/0/0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 7.2.0-rc5 #3 PREEMPTLAZY
RIP: 0010:debug_object_assert_init+0x18f/0x230
Call Trace:
<TASK>
__mod_timer
mce_timer_kick
cmci_discover
intel_init_cmci
mce_intel_feature_init
mcheck_cpu_init
identify_cpu
identify_boot_cpu
arch_cpu_finalize_init
start_kernel
A second splat follows right after, from timer_setup() finding that same
timer already queued:
ODEBUG: init active (active state 0) object: (____ptrval____) object type: timer_list hint: stub_timer+0x0/0x10
This is happening because CMCI storm detection is trying to modify the timer
before latter was properly set up.
Set up the timer first. __mcheck_cpu_setup_timer() only calls timer_setup(),
and depends on neither the generic nor the vendor init.
[ bp: Massage commit message. ]