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X-MS-Exchange-CrossTenant-AuthSource: CY8PR10MB7243.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Sep 2023 15:51:06.9472 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: D7iFR7RXuMpcgzklMdN2dtpx9tgtSqYl5lX0QqSQgLMwOd48H5i7tFe/ntF67nj+rQ1lw2LsP01zfgWSwu6A8sBIJNVO/EeB/3uSc5SbfJc= X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH2PR10MB4245 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.267,Aquarius:18.0.957,Hydra:6.0.601,FMLib:17.11.176.26 definitions=2023-09-06_06,2023-09-05_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 mlxlogscore=999 adultscore=0 phishscore=0 bulkscore=0 mlxscore=0 suspectscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2308100000 definitions=main-2309060138 X-Proofpoint-GUID: bav-dau3u9HbtkW5eNNsckFWTBjoYPQC X-Proofpoint-ORIG-GUID: bav-dau3u9HbtkW5eNNsckFWTBjoYPQC Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/3/23 6:28 AM, Huang Cun wrote: > When a disk fails to attach, the struct rdac_dh_data is released, > but it is not removed from the ctlr->dh_list. When attaching another > disk, the released rdac_dh_data will be accessed and the following > BUG_ON() may be observed: > > [ 414.696167] scsi 5:0:0:7: rdac: Attach failed (8) > ... > [ 423.615364] kernel BUG at drivers/scsi/device_handler/scsi_dh_rdac.c:427! > [ 423.615731] invalid opcode: 0000 [#1] SMP NOPTI > ... > [ 423.623247] Call Trace: > [ 423.623598] rdac_bus_attach+0x203/0x4c0 > [ 423.623949] ? scsi_dh_handler_attach+0x2d/0x90 > [ 423.624300] scsi_dh_handler_attach+0x2d/0x90 > [ 423.624652] scsi_sysfs_add_sdev+0x88/0x270 > [ 423.625004] scsi_probe_and_add_lun+0xc47/0xd50 > [ 423.625354] scsi_report_lun_scan+0x339/0x3b0 > [ 423.625705] __scsi_scan_target+0xe9/0x220 > [ 423.626056] scsi_scan_target+0xf6/0x100 > [ 423.626404] fc_scsi_scan_rport+0xa5/0xb0 > [ 423.626757] process_one_work+0x15e/0x3f0 > [ 423.627106] worker_thread+0x4c/0x440 > [ 423.627453] ? rescuer_thread+0x350/0x350 > [ 423.627804] kthread+0xf8/0x130 > [ 423.628153] ? kthread_destroy_worker+0x40/0x40 > [ 423.628509] ret_from_fork+0x1f/0x40 > > Fixes: 1a5dc166cd88 ("scsi_dh_rdac: update 'access_state' field") > Signed-off-by: Huang Cun > Signed-off-by: Ding Hui > Cc: Donglin Peng > --- > drivers/scsi/device_handler/scsi_dh_rdac.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c b/drivers/scsi/device_handler/scsi_dh_rdac.c > index c5538645057a..9d487c2b7708 100644 > --- a/drivers/scsi/device_handler/scsi_dh_rdac.c > +++ b/drivers/scsi/device_handler/scsi_dh_rdac.c > @@ -762,8 +762,10 @@ static int rdac_bus_attach(struct scsi_device *sdev) > > clean_ctlr: > spin_lock(&list_lock); > + list_del_rcu(&h->node); > kref_put(&h->ctlr->kref, release_controller); > spin_unlock(&list_lock); > + synchronize_rcu(); > Should this be: spin_lock(&list_lock); list_del_rcu(&h->node); spin_unlock(&list_lock); synchronize_rcu(); kref_put(&h->ctlr->kref, release_controller); ? If you do the synchronize_rcu after the kref_put, then the kref_put could free the rdac_dh_data, while check_ownership is still accessing the rdac_dh_data, right?