diff options
| author | Ye Bin | 2021-01-13 14:31:03 +0800 |
|---|---|---|
| committer | Martin K. Petersen | 2021-07-29 21:58:35 -0400 |
| commit | bc546c0c9abb3bb2fb46866b3d1e6ade9695a5f6 (patch) | |
| tree | 1fdea263b82dbf1f29cd73a5490ac773d8b71f78 | |
| parent | 77541f78eadfe9fdb018a7b8b69f0f2af2cf4b82 (diff) | |
scsi: scsi_dh_rdac: Avoid crash during rdac_bus_attach()
The following BUG_ON() was observed during RDAC scan:
[595952.944297] kernel BUG at drivers/scsi/device_handler/scsi_dh_rdac.c:427!
[595952.951143] Internal error: Oops - BUG: 0 [#1] SMP
......
[595953.251065] Call trace:
[595953.259054] check_ownership+0xb0/0x118
[595953.269794] rdac_bus_attach+0x1f0/0x4b0
[595953.273787] scsi_dh_handler_attach+0x3c/0xe8
[595953.278211] scsi_dh_add_device+0xc4/0xe8
[595953.282291] scsi_sysfs_add_sdev+0x8c/0x2a8
[595953.286544] scsi_probe_and_add_lun+0x9fc/0xd00
[595953.291142] __scsi_scan_target+0x598/0x630
[595953.295395] scsi_scan_target+0x120/0x130
[595953.299481] fc_user_scan+0x1a0/0x1c0 [scsi_transport_fc]
[595953.304944] store_scan+0xb0/0x108
[595953.308420] dev_attr_store+0x44/0x60
[595953.312160] sysfs_kf_write+0x58/0x80
[595953.315893] kernfs_fop_write+0xe8/0x1f0
[595953.319888] __vfs_write+0x60/0x190
[595953.323448] vfs_write+0xac/0x1c0
[595953.326836] ksys_write+0x74/0xf0
[595953.330221] __arm64_sys_write+0x24/0x30
Code is in check_ownership:
list_for_each_entry_rcu(tmp, &h->ctlr->dh_list, node) {
/* h->sdev should always be valid */
BUG_ON(!tmp->sdev);
tmp->sdev->access_state = access_state;
}
rdac_bus_attach
initialize_controller
list_add_rcu(&h->node, &h->ctlr->dh_list);
h->sdev = sdev;
rdac_bus_detach
list_del_rcu(&h->node);
h->sdev = NULL;
Fix the race between rdac_bus_attach() and rdac_bus_detach() where h->sdev
is NULL when processing the RDAC attach.
Link: https://lore.kernel.org/r/20210113063103.2698953-1-yebin10@huawei.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
| -rw-r--r-- | drivers/scsi/device_handler/scsi_dh_rdac.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c b/drivers/scsi/device_handler/scsi_dh_rdac.c index 25f6e1ac9e7b..66652ab409cc 100644 --- a/drivers/scsi/device_handler/scsi_dh_rdac.c +++ b/drivers/scsi/device_handler/scsi_dh_rdac.c @@ -453,8 +453,8 @@ static int initialize_controller(struct scsi_device *sdev, if (!h->ctlr) err = SCSI_DH_RES_TEMP_UNAVAIL; else { - list_add_rcu(&h->node, &h->ctlr->dh_list); h->sdev = sdev; + list_add_rcu(&h->node, &h->ctlr->dh_list); } spin_unlock(&list_lock); err = SCSI_DH_OK; @@ -778,11 +778,11 @@ static void rdac_bus_detach( struct scsi_device *sdev ) spin_lock(&list_lock); if (h->ctlr) { list_del_rcu(&h->node); - h->sdev = NULL; kref_put(&h->ctlr->kref, release_controller); } spin_unlock(&list_lock); sdev->handler_data = NULL; + synchronize_rcu(); kfree(h); } |