In the Linux kernel, the following vulnerability has been resolved:
rcu/nocb: Fix rcuog wake-up from offline softirq
After a CPU has set itself offline and before it eventually calls
rcutree_report_cpu_dead(), there are still opportunities for callbacks
to be enqueued, for example from a softirq. When that happens on NOCB,
the rcuog wake-up is deferred through an IPI to an online CPU in order
not to call into the scheduler and risk arming the RT-bandwidth after
hrtimers have been migrated out and disabled.
But performing a synchronized IPI from a softirq is buggy as reported in
the following scenario:
WARNING: CPU: 1 PID: 26 at kernel/smp.c:633 smp_call_function_single
Modules linked in: rcutorture torture
CPU: 1 UID: 0 PID: 26 Comm: migration/1 Not tainted 6.11.0-rc1-00012-g9139f93209d1 #1
Stopper: multi_cpu_stop+0x0/0x320 <- __stop_cpus+0xd0/0x120
RIP: 0010:smp_call_function_single
<IRQ>
swake_up_one_online
__call_rcu_nocb_wake
__call_rcu_common
? rcu_torture_one_read
call_timer_fn
__run_timers
run_timer_softirq
handle_softirqs
irq_exit_rcu
? tick_handle_periodic
sysvec_apic_timer_interrupt
</IRQ>
Fix this with forcing deferred rcuog wake up through the NOCB timer when
the CPU is offline. The actual wake up will happen from
rcutree_report_cpu_dead().
CVSS
No CVSS.
References
Configurations
No configuration.
History
21 Oct 2024, 20:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2024-10-21 20:15
Updated : 2024-10-21 20:15
NVD link : CVE-2024-50032
Mitre link : CVE-2024-50032
CVE.ORG link : CVE-2024-50032
JSON object : View
Products Affected
No product.
CWE
No CWE.