In the Linux kernel, the following vulnerability has been resolved:
workqueue: Fix selection of wake_cpu in kick_pool()
With cpu_possible_mask=0-63 and cpu_online_mask=0-7 the following
kernel oops was observed:
smp: Bringing up secondary CPUs ...
smp: Brought up 1 node, 8 CPUs
Unable to handle kernel pointer dereference in virtual kernel address space
Failing address: 0000000000000000 TEID: 0000000000000803
[..]
Call Trace:
arch_vcpu_is_preempted+0x12/0x80
select_idle_sibling+0x42/0x560
select_task_rq_fair+0x29a/0x3b0
try_to_wake_up+0x38e/0x6e0
kick_pool+0xa4/0x198
__queue_work.part.0+0x2bc/0x3a8
call_timer_fn+0x36/0x160
__run_timers+0x1e2/0x328
__run_timer_base+0x5a/0x88
run_timer_softirq+0x40/0x78
__do_softirq+0x118/0x388
irq_exit_rcu+0xc0/0xd8
do_ext_irq+0xae/0x168
ext_int_handler+0xbe/0xf0
psw_idle_exit+0x0/0xc
default_idle_call+0x3c/0x110
do_idle+0xd4/0x158
cpu_startup_entry+0x40/0x48
rest_init+0xc6/0xc8
start_kernel+0x3c4/0x5e0
startup_continue+0x3c/0x50
The crash is caused by calling arch_vcpu_is_preempted() for an offline
CPU. To avoid this, select the cpu with cpumask_any_and_distribute()
to mask __pod_cpumask with cpu_online_mask. In case no cpu is left in
the pool, skip the assignment.
tj: This doesn't fully fix the bug as CPUs can still go down between picking
the target CPU and the wake call. Fixing that likely requires adding
cpu_online() test to either the sched or s390 arch code. However, regardless
of how that is fixed, workqueue shouldn't be picking a CPU which isn't
online as that would result in unpredictable and worse behavior.
Metrics
Affected Vendors & Products
References
History
Wed, 06 Nov 2024 08:15:00 +0000
Type | Values Removed | Values Added |
---|---|---|
First Time appeared |
Linux
Linux linux Kernel |
|
CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.6:-:*:*:*:*:*:* |
|
Vendors & Products |
Linux
Linux linux Kernel |
|
Metrics |
ssvc
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2024-05-30T15:28:56.214Z
Updated: 2024-11-05T09:27:31.704Z
Reserved: 2024-05-30T15:25:07.065Z
Link: CVE-2024-36888
Vulnrichment
Updated: 2024-08-02T03:43:49.849Z
NVD
Status : Awaiting Analysis
Published: 2024-05-30T16:15:12.323
Modified: 2024-07-03T02:03:42.560
Link: CVE-2024-36888
Redhat