diff options
author | Martin Peschke <mpeschke@linux.vnet.ibm.com> | 2012-09-04 13:23:36 (GMT) |
---|---|---|
committer | James Bottomley <JBottomley@Parallels.com> | 2012-09-24 08:11:02 (GMT) |
commit | d436de8ce25f53a8a880a931886821f632247943 (patch) | |
tree | df2f2056c79b3bd51d4f90fc0f272d46be1adec3 | |
parent | 43f60cbd56c4a3a8f7fb009ac52d6d57ac864921 (diff) | |
download | linux-d436de8ce25f53a8a880a931886821f632247943.tar.xz |
[SCSI] zfcp: only access zfcp_scsi_dev for valid scsi_device
__scsi_remove_device (e.g. due to dev_loss_tmo) calls
zfcp_scsi_slave_destroy which in turn sends a close LUN FSF request to
the adapter. After 30 seconds without response,
zfcp_erp_timeout_handler kicks the ERP thread failing the close LUN
ERP action. zfcp_erp_wait in zfcp_erp_lun_shutdown_wait and thus
zfcp_scsi_slave_destroy returns and then scsi_device is no longer
valid. Sometime later the response to the close LUN FSF request may
finally come in. However, commit
b62a8d9b45b971a67a0f8413338c230e3117dff5
"[SCSI] zfcp: Use SCSI device data zfcp_scsi_dev instead of zfcp_unit"
introduced a number of attempts to unconditionally access struct
zfcp_scsi_dev through struct scsi_device causing a use-after-free.
This leads to an Oops due to kernel page fault in one of:
zfcp_fsf_abort_fcp_command_handler, zfcp_fsf_open_lun_handler,
zfcp_fsf_close_lun_handler, zfcp_fsf_req_trace,
zfcp_fsf_fcp_handler_common.
Move dereferencing of zfcp private data zfcp_scsi_dev allocated in
scsi_device via scsi_transport_reserve_device after the check for
potentially aborted FSF request and thus no longer valid scsi_device.
Only then assign sdev_to_zfcp(sdev) to the local auto variable struct
zfcp_scsi_dev *zfcp_sdev.
Signed-off-by: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> #2.6.37+
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
-rw-r--r-- | drivers/s390/scsi/zfcp_fsf.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c index 9ffdc33..c96320d 100644 --- a/drivers/s390/scsi/zfcp_fsf.c +++ b/drivers/s390/scsi/zfcp_fsf.c @@ -801,12 +801,14 @@ out: static void zfcp_fsf_abort_fcp_command_handler(struct zfcp_fsf_req *req) { struct scsi_device *sdev = req->data; - struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev); + struct zfcp_scsi_dev *zfcp_sdev; union fsf_status_qual *fsq = &req->qtcb->header.fsf_status_qual; if (req->status & ZFCP_STATUS_FSFREQ_ERROR) return; + zfcp_sdev = sdev_to_zfcp(sdev); + switch (req->qtcb->header.fsf_status) { case FSF_PORT_HANDLE_NOT_VALID: if (fsq->word[0] == fsq->word[1]) { @@ -1769,13 +1771,15 @@ static void zfcp_fsf_open_lun_handler(struct zfcp_fsf_req *req) { struct zfcp_adapter *adapter = req->adapter; struct scsi_device *sdev = req->data; - struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev); + struct zfcp_scsi_dev *zfcp_sdev; struct fsf_qtcb_header *header = &req->qtcb->header; struct fsf_qtcb_bottom_support *bottom = &req->qtcb->bottom.support; if (req->status & ZFCP_STATUS_FSFREQ_ERROR) return; + zfcp_sdev = sdev_to_zfcp(sdev); + atomic_clear_mask(ZFCP_STATUS_COMMON_ACCESS_DENIED | ZFCP_STATUS_COMMON_ACCESS_BOXED | ZFCP_STATUS_LUN_SHARED | @@ -1886,11 +1890,13 @@ out: static void zfcp_fsf_close_lun_handler(struct zfcp_fsf_req *req) { struct scsi_device *sdev = req->data; - struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev); + struct zfcp_scsi_dev *zfcp_sdev; if (req->status & ZFCP_STATUS_FSFREQ_ERROR) return; + zfcp_sdev = sdev_to_zfcp(sdev); + switch (req->qtcb->header.fsf_status) { case FSF_PORT_HANDLE_NOT_VALID: zfcp_erp_adapter_reopen(zfcp_sdev->port->adapter, 0, "fscuh_1"); @@ -1980,7 +1986,7 @@ static void zfcp_fsf_req_trace(struct zfcp_fsf_req *req, struct scsi_cmnd *scsi) { struct fsf_qual_latency_info *lat_in; struct latency_cont *lat = NULL; - struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(scsi->device); + struct zfcp_scsi_dev *zfcp_sdev; struct zfcp_blk_drv_data blktrc; int ticks = req->adapter->timer_ticks; @@ -1995,6 +2001,7 @@ static void zfcp_fsf_req_trace(struct zfcp_fsf_req *req, struct scsi_cmnd *scsi) if (req->adapter->adapter_features & FSF_FEATURE_MEASUREMENT_DATA && !(req->status & ZFCP_STATUS_FSFREQ_ERROR)) { + zfcp_sdev = sdev_to_zfcp(scsi->device); blktrc.flags |= ZFCP_BLK_LAT_VALID; blktrc.channel_lat = lat_in->channel_lat * ticks; blktrc.fabric_lat = lat_in->fabric_lat * ticks; @@ -2032,12 +2039,14 @@ static void zfcp_fsf_fcp_handler_common(struct zfcp_fsf_req *req) { struct scsi_cmnd *scmnd = req->data; struct scsi_device *sdev = scmnd->device; - struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev); + struct zfcp_scsi_dev *zfcp_sdev; struct fsf_qtcb_header *header = &req->qtcb->header; if (unlikely(req->status & ZFCP_STATUS_FSFREQ_ERROR)) return; + zfcp_sdev = sdev_to_zfcp(sdev); + switch (header->fsf_status) { case FSF_HANDLE_MISMATCH: case FSF_PORT_HANDLE_NOT_VALID: |