hulk inclusion category: bugfix bugzilla: 188032, https://gitee.com/openeuler/kernel/issues/I64T3E CVE: NA
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Our test found the following problem in kernel 5.10:
BUG: KASAN: use-after-free in _raw_spin_lock_irqsave+0x71/0xe0 Write of size 4 at addr ffff8881432000e0 by task swapper/4/0 ... Call Trace: <IRQ> dump_stack+0x9c/0xd3 print_address_description.constprop.0+0x19/0x170 __kasan_report.cold+0x6c/0x84 kasan_report+0x3a/0x50 check_memory_region+0xfd/0x1f0 _raw_spin_lock_irqsave+0x71/0xe0 ioc_pd_free+0x9d/0x250 blkg_free.part.0+0x80/0x100 __blkg_release+0xf3/0x1c0 rcu_do_batch+0x292/0x700 rcu_core+0x270/0x2d0 __do_softirq+0xfd/0x402 </IRQ> asm_call_irq_on_stack+0x12/0x20 do_softirq_own_stack+0x37/0x50 irq_exit_rcu+0x134/0x1a0 sysvec_apic_timer_interrupt+0x36/0x80 asm_sysvec_apic_timer_interrupt+0x12/0x20
Freed by task 57: kfree+0xba/0x680 rq_qos_exit+0x5a/0x80 blk_cleanup_queue+0xce/0x1a0 virtblk_remove+0x77/0x130 [virtio_blk] virtio_dev_remove+0x56/0xe0 __device_release_driver+0x2ba/0x450 device_release_driver+0x29/0x40 bus_remove_device+0x1d8/0x2c0 device_del+0x333/0x7e0 device_unregister+0x27/0x90 unregister_virtio_device+0x22/0x40 virtio_pci_remove+0x53/0xb0 pci_device_remove+0x7a/0x130 __device_release_driver+0x2ba/0x450 device_release_driver+0x29/0x40 pci_stop_bus_device+0xcf/0x100 pci_stop_and_remove_bus_device+0x16/0x20 disable_slot+0xa1/0x110 acpiphp_disable_and_eject_slot+0x35/0xe0 hotplug_event+0x1b8/0x3c0 acpiphp_hotplug_notify+0x37/0x70 acpi_device_hotplug+0xee/0x320 acpi_hotplug_work_fn+0x69/0x80 process_one_work+0x3c5/0x730 worker_thread+0x93/0x650 kthread+0x1ba/0x210 ret_from_fork+0x22/0x30
It happened as follow:
T1 T2 T3 T4 //delete device del_gendisk bdi_unregister bdi_remove_from_list synchronize_rcu_expedited
//rmdir cgroup blkcg_destroy_blkgs blkg_destroy percpu_ref_kill blkg_release call_rcu blk_cleanup_queue rq_qos_exit ioc_rqos_exit kfree(ioc) __blkg_release blkg_free blkg_free_workfn pd_free_fn ioc_pd_free spin_lock_irqsave ->ioc is freed
Fix the problem by moving the operation on ioc in ioc_pd_free() to ioc_pd_offline(), and just free resource in ioc_pd_free() like iolatency and throttle.
Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost") Signed-off-by: Li Nan linan122@huawei.com --- block/blk-iocost.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/block/blk-iocost.c b/block/blk-iocost.c index c87320fa221e..9b9b7cce21d4 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -2957,7 +2957,7 @@ static void ioc_pd_init(struct blkg_policy_data *pd) spin_unlock_irqrestore(&ioc->lock, flags); }
-static void ioc_pd_free(struct blkg_policy_data *pd) +static void ioc_pd_offline(struct blkg_policy_data *pd) { struct ioc_gq *iocg = pd_to_iocg(pd); struct ioc *ioc = iocg->ioc; @@ -2981,6 +2981,12 @@ static void ioc_pd_free(struct blkg_policy_data *pd)
hrtimer_cancel(&iocg->waitq_timer); } +} + +static void ioc_pd_free(struct blkg_policy_data *pd) +{ + struct ioc_gq *iocg = pd_to_iocg(pd); + free_percpu(iocg->pcpu_stat); kfree(iocg); } @@ -3453,6 +3459,7 @@ static struct blkcg_policy blkcg_policy_iocost = { .cpd_free_fn = ioc_cpd_free, .pd_alloc_fn = ioc_pd_alloc, .pd_init_fn = ioc_pd_init, + .pd_offline_fn = ioc_pd_offline, .pd_free_fn = ioc_pd_free, .pd_stat_fn = ioc_pd_stat, };