Message ID | 1566182345-7544-1-git-send-email-zhengbin13@huawei.com (mailing list archive) |
---|---|
State | Not Applicable |
Headers | show |
Series | [4.19-stable] SCSI: fix queue cleanup race before scsi_requeue_run_queue is done | expand |
On Mon, Aug 19, 2019 at 10:39:05AM +0800, zhengbin wrote: > KASAN reports a use-after-free in 4.19-stable, > which won't happen after commit 47cdee29ef9d > ("block: move blk_exit_queue into __blk_release_queue"). > However, backport this patch to 4.19-stable will be a lot of work and > the risk is great. Moreover, we should make sure scsi_requeue_run_queue > is done before blk_cleanup_queue. I have backported that patchset to v4.18 based kernel, and it won't take lots of work at all. > > BUG: KASAN: use-after-free in dd_has_work+0x50/0xe8 > Read of size 8 at addr ffff808b57c6f168 by task kworker/53:1H/6910 > > CPU: 53 PID: 6910 Comm: kworker/53:1H Kdump: loaded Tainted: G > Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.59 01/31/2019 > Workqueue: kblockd scsi_requeue_run_queue > Call trace: > dump_backtrace+0x0/0x270 > show_stack+0x24/0x30 > dump_stack+0xb4/0xe4 > print_address_description+0x68/0x278 > kasan_report+0x204/0x330 > __asan_load8+0x88/0xb0 > dd_has_work+0x50/0xe8 > blk_mq_run_hw_queue+0x19c/0x218 > blk_mq_run_hw_queues+0x7c/0xb0 > scsi_run_queue+0x3ec/0x520 > scsi_requeue_run_queue+0x2c/0x38 > process_one_work+0x2e4/0x6d8 > worker_thread+0x6c/0x6a8 > kthread+0x1b4/0x1c0 > ret_from_fork+0x10/0x18 > > Allocated by task 46843: > kasan_kmalloc+0xe0/0x190 > kmem_cache_alloc_node_trace+0x10c/0x258 > dd_init_queue+0x68/0x190 > blk_mq_init_sched+0x1cc/0x300 > elevator_init_mq+0x90/0xe0 > blk_mq_init_allocated_queue+0x700/0x728 > blk_mq_init_queue+0x48/0x90 > scsi_mq_alloc_queue+0x34/0xb0 > scsi_alloc_sdev+0x340/0x530 > scsi_probe_and_add_lun+0x46c/0x1260 > __scsi_scan_target+0x1b8/0x7b0 > scsi_scan_target+0x140/0x150 > fc_scsi_scan_rport+0x164/0x178 [scsi_transport_fc] > process_one_work+0x2e4/0x6d8 > worker_thread+0x6c/0x6a8 > kthread+0x1b4/0x1c0 > ret_from_fork+0x10/0x18 > > Freed by task 46843: > __kasan_slab_free+0x120/0x228 > kasan_slab_free+0x10/0x18 > kfree+0x88/0x218 > dd_exit_queue+0x5c/0x78 > blk_mq_exit_sched+0x104/0x130 > elevator_exit+0xa8/0xc8 > blk_exit_queue+0x48/0x78 > blk_cleanup_queue+0x170/0x248 > __scsi_remove_device+0x84/0x1b0 > scsi_probe_and_add_lun+0xd00/0x1260 > __scsi_scan_target+0x1b8/0x7b0 > scsi_scan_target+0x140/0x150 > fc_scsi_scan_rport+0x164/0x178 [scsi_transport_fc] > process_one_work+0x2e4/0x6d8 > worker_thread+0x6c/0x6a8 > kthread+0x1b4/0x1c0 > ret_from_fork+0x10/0x18 > > Fixes: 8dc765d438f1 ("SCSI: fix queue cleanup race before queue initialization is done") > Signed-off-by: zhengbin <zhengbin13@huawei.com> > --- > drivers/scsi/scsi_lib.c | 24 ++++++++++++++++++------ > drivers/scsi/scsi_sysfs.c | 3 ++- > 2 files changed, 20 insertions(+), 7 deletions(-) > > diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c > index 75b926e..42f1475 100644 > --- a/drivers/scsi/scsi_lib.c > +++ b/drivers/scsi/scsi_lib.c > @@ -208,7 +208,13 @@ static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy) > } > spin_lock_irqsave(q->queue_lock, flags); > blk_requeue_request(q, cmd->request); > - kblockd_schedule_work(&device->requeue_work); > + /* > + * need to get q_usage_counter which will be > + * put in scsi_requeue_run_queue. > + */ > + percpu_ref_get(&q->q_usage_counter); > + if (!kblockd_schedule_work(&device->requeue_work)) > + percpu_ref_put(&q->q_usage_counter); > spin_unlock_irqrestore(q->queue_lock, flags); > } > > @@ -548,6 +554,11 @@ void scsi_requeue_run_queue(struct work_struct *work) > sdev = container_of(work, struct scsi_device, requeue_work); > q = sdev->request_queue; > scsi_run_queue(q); > + /* > + * need to put q_usage_counter which is got in > + * scsi_end_request or __scsi_queue_insert. > + */ > + percpu_ref_put(&q->q_usage_counter); > } > > /* > @@ -706,12 +717,13 @@ static bool scsi_end_request(struct request *req, blk_status_t error, > __blk_mq_end_request(req, error); > > if (scsi_target(sdev)->single_lun || > - !list_empty(&sdev->host->starved_list)) > - kblockd_schedule_work(&sdev->requeue_work); > - else > + !list_empty(&sdev->host->starved_list)) { > + if (!kblockd_schedule_work(&sdev->requeue_work)) > + percpu_ref_put(&q->q_usage_counter); > + } else { > blk_mq_run_hw_queues(q, true); > - > - percpu_ref_put(&q->q_usage_counter); > + percpu_ref_put(&q->q_usage_counter); > + } > } else { > unsigned long flags; > > diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c > index 3aee946..2dc422e 100644 > --- a/drivers/scsi/scsi_sysfs.c > +++ b/drivers/scsi/scsi_sysfs.c > @@ -1392,7 +1392,8 @@ void __scsi_remove_device(struct scsi_device *sdev) > mutex_unlock(&sdev->state_mutex); > > blk_cleanup_queue(sdev->request_queue); > - cancel_work_sync(&sdev->requeue_work); > + if (cancel_work_sync(&sdev->requeue_work)) > + percpu_ref_put(&sdev->request_queue->q_usage_counter); > > if (sdev->host->hostt->slave_destroy) > sdev->host->hostt->slave_destroy(sdev); Getting/putting the percpu ref from different contexts is just a nightmare for maintaining the correctness. Thanks, Ming
On 2019/8/19 12:08, Ming Lei wrote: > On Mon, Aug 19, 2019 at 10:39:05AM +0800, zhengbin wrote: >> KASAN reports a use-after-free in 4.19-stable, >> which won't happen after commit 47cdee29ef9d >> ("block: move blk_exit_queue into __blk_release_queue"). >> However, backport this patch to 4.19-stable will be a lot of work and >> the risk is great. Moreover, we should make sure scsi_requeue_run_queue >> is done before blk_cleanup_queue. > I have backported that patchset to v4.18 based kernel, and it won't > take lots of work at all. In fact, I want to backport it to 4.19, if backport, we need to do: 1. need to backport 0d945c1f966b ("block: remove the queue_lock indirection"), cause commit 47cdee29ef9d ("block: move blk_exit_queue into __blk_release_queue") reverts a063057d7c73 ("block: Fix a race between request queue removal and the block cgroup controller"), if we do not backport 0d945c1f966b, the bug fixed by a063057d7c73 will exist too. 2. If we backport 0d945c1f966b, see the comment: "With the legacy request path gone there is no good reason to keep queue_lock as a pointer". we need to backport the driver patches which kill the queue_lock. For example: 89c6b1650969 ("paride: convert pcd to blk-mq") --->the second para of blk_init_queue is queue_lock 99fe8b02a825 ("paride: convert pd to blk-mq") ... 3. In SCSI, 4.19-stable has blk-sq(single queue) & mq. Blk-sq uses queue_lock, while these need to adapt. For example: scsi_lib.c: spin_lock_irqsave(q->queue_lock, flags); scsi_lib.c: spin_unlock_irqrestore(q->queue_lock, flags); scsi_lib.c: * drops the queue_lock and can add us back to the scsi_lib.c: spin_lock_irqsave(q->queue_lock, flags); scsi_lib.c: spin_unlock_irqrestore(q->queue_lock, flags); scsi_lib.c: spin_lock_irqsave(q->queue_lock, flags); scsi_lib.c: spin_unlock_irqrestore(q->queue_lock, flags); scsi_lib.c: * Called with the queue_lock held. ... >> BUG: KASAN: use-after-free in dd_has_work+0x50/0xe8 >> Read of size 8 at addr ffff808b57c6f168 by task kworker/53:1H/6910 >> >> CPU: 53 PID: 6910 Comm: kworker/53:1H Kdump: loaded Tainted: G >> Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.59 01/31/2019 >> Workqueue: kblockd scsi_requeue_run_queue >> Call trace: >> dump_backtrace+0x0/0x270 >> show_stack+0x24/0x30 >> dump_stack+0xb4/0xe4 >> print_address_description+0x68/0x278 >> kasan_report+0x204/0x330 >> __asan_load8+0x88/0xb0 >> dd_has_work+0x50/0xe8 >> blk_mq_run_hw_queue+0x19c/0x218 >> blk_mq_run_hw_queues+0x7c/0xb0 >> scsi_run_queue+0x3ec/0x520 >> scsi_requeue_run_queue+0x2c/0x38 >> process_one_work+0x2e4/0x6d8 >> worker_thread+0x6c/0x6a8 >> kthread+0x1b4/0x1c0 >> ret_from_fork+0x10/0x18 >> >> Allocated by task 46843: >> kasan_kmalloc+0xe0/0x190 >> kmem_cache_alloc_node_trace+0x10c/0x258 >> dd_init_queue+0x68/0x190 >> blk_mq_init_sched+0x1cc/0x300 >> elevator_init_mq+0x90/0xe0 >> blk_mq_init_allocated_queue+0x700/0x728 >> blk_mq_init_queue+0x48/0x90 >> scsi_mq_alloc_queue+0x34/0xb0 >> scsi_alloc_sdev+0x340/0x530 >> scsi_probe_and_add_lun+0x46c/0x1260 >> __scsi_scan_target+0x1b8/0x7b0 >> scsi_scan_target+0x140/0x150 >> fc_scsi_scan_rport+0x164/0x178 [scsi_transport_fc] >> process_one_work+0x2e4/0x6d8 >> worker_thread+0x6c/0x6a8 >> kthread+0x1b4/0x1c0 >> ret_from_fork+0x10/0x18 >> >> Freed by task 46843: >> __kasan_slab_free+0x120/0x228 >> kasan_slab_free+0x10/0x18 >> kfree+0x88/0x218 >> dd_exit_queue+0x5c/0x78 >> blk_mq_exit_sched+0x104/0x130 >> elevator_exit+0xa8/0xc8 >> blk_exit_queue+0x48/0x78 >> blk_cleanup_queue+0x170/0x248 >> __scsi_remove_device+0x84/0x1b0 >> scsi_probe_and_add_lun+0xd00/0x1260 >> __scsi_scan_target+0x1b8/0x7b0 >> scsi_scan_target+0x140/0x150 >> fc_scsi_scan_rport+0x164/0x178 [scsi_transport_fc] >> process_one_work+0x2e4/0x6d8 >> worker_thread+0x6c/0x6a8 >> kthread+0x1b4/0x1c0 >> ret_from_fork+0x10/0x18 >> >> Fixes: 8dc765d438f1 ("SCSI: fix queue cleanup race before queue initialization is done") >> Signed-off-by: zhengbin <zhengbin13@huawei.com> >> --- >> drivers/scsi/scsi_lib.c | 24 ++++++++++++++++++------ >> drivers/scsi/scsi_sysfs.c | 3 ++- >> 2 files changed, 20 insertions(+), 7 deletions(-) >> >> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c >> index 75b926e..42f1475 100644 >> --- a/drivers/scsi/scsi_lib.c >> +++ b/drivers/scsi/scsi_lib.c >> @@ -208,7 +208,13 @@ static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy) >> } >> spin_lock_irqsave(q->queue_lock, flags); >> blk_requeue_request(q, cmd->request); >> - kblockd_schedule_work(&device->requeue_work); >> + /* >> + * need to get q_usage_counter which will be >> + * put in scsi_requeue_run_queue. >> + */ >> + percpu_ref_get(&q->q_usage_counter); >> + if (!kblockd_schedule_work(&device->requeue_work)) >> + percpu_ref_put(&q->q_usage_counter); >> spin_unlock_irqrestore(q->queue_lock, flags); >> } >> >> @@ -548,6 +554,11 @@ void scsi_requeue_run_queue(struct work_struct *work) >> sdev = container_of(work, struct scsi_device, requeue_work); >> q = sdev->request_queue; >> scsi_run_queue(q); >> + /* >> + * need to put q_usage_counter which is got in >> + * scsi_end_request or __scsi_queue_insert. >> + */ >> + percpu_ref_put(&q->q_usage_counter); >> } >> >> /* >> @@ -706,12 +717,13 @@ static bool scsi_end_request(struct request *req, blk_status_t error, >> __blk_mq_end_request(req, error); >> >> if (scsi_target(sdev)->single_lun || >> - !list_empty(&sdev->host->starved_list)) >> - kblockd_schedule_work(&sdev->requeue_work); >> - else >> + !list_empty(&sdev->host->starved_list)) { >> + if (!kblockd_schedule_work(&sdev->requeue_work)) >> + percpu_ref_put(&q->q_usage_counter); >> + } else { >> blk_mq_run_hw_queues(q, true); >> - >> - percpu_ref_put(&q->q_usage_counter); >> + percpu_ref_put(&q->q_usage_counter); >> + } >> } else { >> unsigned long flags; >> >> diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c >> index 3aee946..2dc422e 100644 >> --- a/drivers/scsi/scsi_sysfs.c >> +++ b/drivers/scsi/scsi_sysfs.c >> @@ -1392,7 +1392,8 @@ void __scsi_remove_device(struct scsi_device *sdev) >> mutex_unlock(&sdev->state_mutex); >> >> blk_cleanup_queue(sdev->request_queue); >> - cancel_work_sync(&sdev->requeue_work); >> + if (cancel_work_sync(&sdev->requeue_work)) >> + percpu_ref_put(&sdev->request_queue->q_usage_counter); >> >> if (sdev->host->hostt->slave_destroy) >> sdev->host->hostt->slave_destroy(sdev); > Getting/putting the percpu ref from different contexts is just a > nightmare for maintaining the correctness. > > > Thanks, > Ming > > . >
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 75b926e..42f1475 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -208,7 +208,13 @@ static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy) } spin_lock_irqsave(q->queue_lock, flags); blk_requeue_request(q, cmd->request); - kblockd_schedule_work(&device->requeue_work); + /* + * need to get q_usage_counter which will be + * put in scsi_requeue_run_queue. + */ + percpu_ref_get(&q->q_usage_counter); + if (!kblockd_schedule_work(&device->requeue_work)) + percpu_ref_put(&q->q_usage_counter); spin_unlock_irqrestore(q->queue_lock, flags); } @@ -548,6 +554,11 @@ void scsi_requeue_run_queue(struct work_struct *work) sdev = container_of(work, struct scsi_device, requeue_work); q = sdev->request_queue; scsi_run_queue(q); + /* + * need to put q_usage_counter which is got in + * scsi_end_request or __scsi_queue_insert. + */ + percpu_ref_put(&q->q_usage_counter); } /* @@ -706,12 +717,13 @@ static bool scsi_end_request(struct request *req, blk_status_t error, __blk_mq_end_request(req, error); if (scsi_target(sdev)->single_lun || - !list_empty(&sdev->host->starved_list)) - kblockd_schedule_work(&sdev->requeue_work); - else + !list_empty(&sdev->host->starved_list)) { + if (!kblockd_schedule_work(&sdev->requeue_work)) + percpu_ref_put(&q->q_usage_counter); + } else { blk_mq_run_hw_queues(q, true); - - percpu_ref_put(&q->q_usage_counter); + percpu_ref_put(&q->q_usage_counter); + } } else { unsigned long flags; diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 3aee946..2dc422e 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -1392,7 +1392,8 @@ void __scsi_remove_device(struct scsi_device *sdev) mutex_unlock(&sdev->state_mutex); blk_cleanup_queue(sdev->request_queue); - cancel_work_sync(&sdev->requeue_work); + if (cancel_work_sync(&sdev->requeue_work)) + percpu_ref_put(&sdev->request_queue->q_usage_counter); if (sdev->host->hostt->slave_destroy) sdev->host->hostt->slave_destroy(sdev);
KASAN reports a use-after-free in 4.19-stable, which won't happen after commit 47cdee29ef9d ("block: move blk_exit_queue into __blk_release_queue"). However, backport this patch to 4.19-stable will be a lot of work and the risk is great. Moreover, we should make sure scsi_requeue_run_queue is done before blk_cleanup_queue. BUG: KASAN: use-after-free in dd_has_work+0x50/0xe8 Read of size 8 at addr ffff808b57c6f168 by task kworker/53:1H/6910 CPU: 53 PID: 6910 Comm: kworker/53:1H Kdump: loaded Tainted: G Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.59 01/31/2019 Workqueue: kblockd scsi_requeue_run_queue Call trace: dump_backtrace+0x0/0x270 show_stack+0x24/0x30 dump_stack+0xb4/0xe4 print_address_description+0x68/0x278 kasan_report+0x204/0x330 __asan_load8+0x88/0xb0 dd_has_work+0x50/0xe8 blk_mq_run_hw_queue+0x19c/0x218 blk_mq_run_hw_queues+0x7c/0xb0 scsi_run_queue+0x3ec/0x520 scsi_requeue_run_queue+0x2c/0x38 process_one_work+0x2e4/0x6d8 worker_thread+0x6c/0x6a8 kthread+0x1b4/0x1c0 ret_from_fork+0x10/0x18 Allocated by task 46843: kasan_kmalloc+0xe0/0x190 kmem_cache_alloc_node_trace+0x10c/0x258 dd_init_queue+0x68/0x190 blk_mq_init_sched+0x1cc/0x300 elevator_init_mq+0x90/0xe0 blk_mq_init_allocated_queue+0x700/0x728 blk_mq_init_queue+0x48/0x90 scsi_mq_alloc_queue+0x34/0xb0 scsi_alloc_sdev+0x340/0x530 scsi_probe_and_add_lun+0x46c/0x1260 __scsi_scan_target+0x1b8/0x7b0 scsi_scan_target+0x140/0x150 fc_scsi_scan_rport+0x164/0x178 [scsi_transport_fc] process_one_work+0x2e4/0x6d8 worker_thread+0x6c/0x6a8 kthread+0x1b4/0x1c0 ret_from_fork+0x10/0x18 Freed by task 46843: __kasan_slab_free+0x120/0x228 kasan_slab_free+0x10/0x18 kfree+0x88/0x218 dd_exit_queue+0x5c/0x78 blk_mq_exit_sched+0x104/0x130 elevator_exit+0xa8/0xc8 blk_exit_queue+0x48/0x78 blk_cleanup_queue+0x170/0x248 __scsi_remove_device+0x84/0x1b0 scsi_probe_and_add_lun+0xd00/0x1260 __scsi_scan_target+0x1b8/0x7b0 scsi_scan_target+0x140/0x150 fc_scsi_scan_rport+0x164/0x178 [scsi_transport_fc] process_one_work+0x2e4/0x6d8 worker_thread+0x6c/0x6a8 kthread+0x1b4/0x1c0 ret_from_fork+0x10/0x18 Fixes: 8dc765d438f1 ("SCSI: fix queue cleanup race before queue initialization is done") Signed-off-by: zhengbin <zhengbin13@huawei.com> --- drivers/scsi/scsi_lib.c | 24 ++++++++++++++++++------ drivers/scsi/scsi_sysfs.c | 3 ++- 2 files changed, 20 insertions(+), 7 deletions(-) -- 2.7.4