| Message ID | 20240723115047.13092-1-mheyne@amazon.de |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [5.10] scsi: core: Fix a use-after-free | expand |
On Tue, Jul 23, 2024 at 11:50:46AM +0000, Maximilian Heyne wrote: > From: Bart Van Assche <bvanassche@acm.org> > > [ Upstream commit 8fe4ce5836e932f5766317cb651c1ff2a4cd0506 ] > > There are two .exit_cmd_priv implementations. Both implementations use > resources associated with the SCSI host. Make sure that these resources are > still available when .exit_cmd_priv is called by waiting inside > scsi_remove_host() until the tag set has been freed. > > This commit fixes the following use-after-free: > > ================================================================== > BUG: KASAN: use-after-free in srp_exit_cmd_priv+0x27/0xd0 [ib_srp] > Read of size 8 at addr ffff888100337000 by task multipathd/16727 > Call Trace: > <TASK> > dump_stack_lvl+0x34/0x44 > print_report.cold+0x5e/0x5db > kasan_report+0xab/0x120 > srp_exit_cmd_priv+0x27/0xd0 [ib_srp] > scsi_mq_exit_request+0x4d/0x70 > blk_mq_free_rqs+0x143/0x410 > __blk_mq_free_map_and_rqs+0x6e/0x100 > blk_mq_free_tag_set+0x2b/0x160 > scsi_host_dev_release+0xf3/0x1a0 > device_release+0x54/0xe0 > kobject_put+0xa5/0x120 > device_release+0x54/0xe0 > kobject_put+0xa5/0x120 > scsi_device_dev_release_usercontext+0x4c1/0x4e0 > execute_in_process_context+0x23/0x90 > device_release+0x54/0xe0 > kobject_put+0xa5/0x120 > scsi_disk_release+0x3f/0x50 > device_release+0x54/0xe0 > kobject_put+0xa5/0x120 > disk_release+0x17f/0x1b0 > device_release+0x54/0xe0 > kobject_put+0xa5/0x120 > dm_put_table_device+0xa3/0x160 [dm_mod] > dm_put_device+0xd0/0x140 [dm_mod] > free_priority_group+0xd8/0x110 [dm_multipath] > free_multipath+0x94/0xe0 [dm_multipath] > dm_table_destroy+0xa2/0x1e0 [dm_mod] > __dm_destroy+0x196/0x350 [dm_mod] > dev_remove+0x10c/0x160 [dm_mod] > ctl_ioctl+0x2c2/0x590 [dm_mod] > dm_ctl_ioctl+0x5/0x10 [dm_mod] > __x64_sys_ioctl+0xb4/0xf0 > dm_ctl_ioctl+0x5/0x10 [dm_mod] > __x64_sys_ioctl+0xb4/0xf0 > do_syscall_64+0x3b/0x90 > entry_SYSCALL_64_after_hwframe+0x46/0xb0 > > Link: https://lore.kernel.org/r/20220826002635.919423-1-bvanassche@acm.org > Fixes: 65ca846a5314 ("scsi: core: Introduce {init,exit}_cmd_priv()") > Cc: Ming Lei <ming.lei@redhat.com> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Mike Christie <michael.christie@oracle.com> > Cc: Hannes Reinecke <hare@suse.de> > Cc: John Garry <john.garry@huawei.com> > Cc: Li Zhijian <lizhijian@fujitsu.com> > Reported-by: Li Zhijian <lizhijian@fujitsu.com> > Tested-by: Li Zhijian <lizhijian@fujitsu.com> > Signed-off-by: Bart Van Assche <bvanassche@acm.org> > Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> > [mheyne: fixed contextual conflicts: > - drivers/scsi/hosts.c: due to missing commit 973dac8a8a14 ("scsi: core: Refine how we set tag_set NUMA node") > - drivers/scsi/scsi_sysfs.c: due to missing commit 6f8191fdf41d ("block: simplify disk shutdown") > - drivers/scsi/scsi_scan.c: due to missing commit 59506abe5e34 ("scsi: core: Inline scsi_mq_alloc_queue()")] > Signed-off-by: Maximilian Heyne <mheyne@amazon.de> > Cc: stable@vger.kernel.org # v5.10 Both now backported, thanks. greg k-h
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 297f2b412d07..17fa1cd91da6 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -182,6 +182,15 @@ void scsi_remove_host(struct Scsi_Host *shost) scsi_proc_host_rm(shost); scsi_proc_hostdir_rm(shost->hostt); + /* + * New SCSI devices cannot be attached anymore because of the SCSI host + * state so drop the tag set refcnt. Wait until the tag set refcnt drops + * to zero because .exit_cmd_priv implementations may need the host + * pointer. + */ + kref_put(&shost->tagset_refcnt, scsi_mq_free_tags); + wait_for_completion(&shost->tagset_freed); + spin_lock_irqsave(shost->host_lock, flags); if (scsi_host_set_state(shost, SHOST_DEL)) BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY)); @@ -240,6 +249,9 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, shost->dma_dev = dma_dev; + kref_init(&shost->tagset_refcnt); + init_completion(&shost->tagset_freed); + /* * Increase usage count temporarily here so that calling * scsi_autopm_put_host() will trigger runtime idle if there is @@ -312,6 +324,7 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, pm_runtime_disable(&shost->shost_gendev); pm_runtime_set_suspended(&shost->shost_gendev); pm_runtime_put_noidle(&shost->shost_gendev); + kref_put(&shost->tagset_refcnt, scsi_mq_free_tags); fail: return error; } @@ -344,9 +357,6 @@ static void scsi_host_dev_release(struct device *dev) kfree(dev_name(&shost->shost_dev)); } - if (shost->tag_set.tags) - scsi_mq_destroy_tags(shost); - kfree(shost->shost_data); ida_simple_remove(&host_index_ida, shost->host_no); diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 14dec86ff749..64ae7bc2de60 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1923,9 +1923,13 @@ int scsi_mq_setup_tags(struct Scsi_Host *shost) return blk_mq_alloc_tag_set(tag_set); } -void scsi_mq_destroy_tags(struct Scsi_Host *shost) +void scsi_mq_free_tags(struct kref *kref) { + struct Scsi_Host *shost = container_of(kref, typeof(*shost), + tagset_refcnt); + blk_mq_free_tag_set(&shost->tag_set); + complete(&shost->tagset_freed); } /** diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h index 1183dbed687c..3fee9af05925 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -93,7 +93,7 @@ extern void scsi_requeue_run_queue(struct work_struct *work); extern struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev); extern void scsi_start_queue(struct scsi_device *sdev); extern int scsi_mq_setup_tags(struct Scsi_Host *shost); -extern void scsi_mq_destroy_tags(struct Scsi_Host *shost); +extern void scsi_mq_free_tags(struct kref *kref); extern void scsi_exit_queue(void); extern void scsi_evt_thread(struct work_struct *work); struct request_queue; diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 6f7c4d41c51d..e8703b043805 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -273,6 +273,7 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, kfree(sdev); goto out; } + kref_get(&sdev->host->tagset_refcnt); WARN_ON_ONCE(!blk_get_queue(sdev->request_queue)); sdev->request_queue->queuedata = sdev; diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 6cc4d0792e3d..bb37d698da1a 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -1481,6 +1481,7 @@ void __scsi_remove_device(struct scsi_device *sdev) mutex_unlock(&sdev->state_mutex); blk_cleanup_queue(sdev->request_queue); + kref_put(&sdev->host->tagset_refcnt, scsi_mq_free_tags); cancel_work_sync(&sdev->requeue_work); if (sdev->host->hostt->slave_destroy) diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index 4a9f1e6e3aac..3979e946c3fd 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -548,6 +548,8 @@ struct Scsi_Host { struct scsi_host_template *hostt; struct scsi_transport_template *transportt; + struct kref tagset_refcnt; + struct completion tagset_freed; /* Area to keep a shared tag map */ struct blk_mq_tag_set tag_set;