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authorBenjamin Block <bblock@linux.ibm.com>2019-07-02 23:02:01 +0200
committerMartin K. Petersen <martin.petersen@oracle.com>2019-07-11 21:04:22 -0400
commit106d45f350c7cac876844dc685845cba4ffdb70b (patch)
tree6f68cf4e5780c123d2b51f3513fb822e21045886 /drivers/s390/scsi
parentscsi: zfcp: fix request object use-after-free in send path causing seqno errors (diff)
downloadlinux-dev-106d45f350c7cac876844dc685845cba4ffdb70b.tar.xz
linux-dev-106d45f350c7cac876844dc685845cba4ffdb70b.zip
scsi: zfcp: fix request object use-after-free in send path causing wrong traces
When tracing instances where we open and close WKA ports, we also pass the request-ID of the respective FSF command. But after successfully sending the FSF command we must not use the request-object anymore, as this might result in an use-after-free (see "zfcp: fix request object use-after-free in send path causing seqno errors" ). To fix this add a new variable that caches the request-ID before sending the request. This won't change during the hand-off to the FCP channel, and so it's safe to trace this cached request-ID later, instead of using the request object. Signed-off-by: Benjamin Block <bblock@linux.ibm.com> Fixes: d27a7cb91960 ("zfcp: trace on request for open and close of WKA port") Cc: <stable@vger.kernel.org> #2.6.38+ Reviewed-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/s390/scsi')
-rw-r--r--drivers/s390/scsi/zfcp_fsf.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index c5b2615b49ef..296bbc3c4606 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -1627,6 +1627,7 @@ int zfcp_fsf_open_wka_port(struct zfcp_fc_wka_port *wka_port)
{
struct zfcp_qdio *qdio = wka_port->adapter->qdio;
struct zfcp_fsf_req *req;
+ unsigned long req_id = 0;
int retval = -EIO;
spin_lock_irq(&qdio->req_q_lock);
@@ -1649,6 +1650,8 @@ int zfcp_fsf_open_wka_port(struct zfcp_fc_wka_port *wka_port)
hton24(req->qtcb->bottom.support.d_id, wka_port->d_id);
req->data = wka_port;
+ req_id = req->req_id;
+
zfcp_fsf_start_timer(req, ZFCP_FSF_REQUEST_TIMEOUT);
retval = zfcp_fsf_req_send(req);
if (retval)
@@ -1657,7 +1660,7 @@ int zfcp_fsf_open_wka_port(struct zfcp_fc_wka_port *wka_port)
out:
spin_unlock_irq(&qdio->req_q_lock);
if (!retval)
- zfcp_dbf_rec_run_wka("fsowp_1", wka_port, req->req_id);
+ zfcp_dbf_rec_run_wka("fsowp_1", wka_port, req_id);
return retval;
}
@@ -1683,6 +1686,7 @@ int zfcp_fsf_close_wka_port(struct zfcp_fc_wka_port *wka_port)
{
struct zfcp_qdio *qdio = wka_port->adapter->qdio;
struct zfcp_fsf_req *req;
+ unsigned long req_id = 0;
int retval = -EIO;
spin_lock_irq(&qdio->req_q_lock);
@@ -1705,6 +1709,8 @@ int zfcp_fsf_close_wka_port(struct zfcp_fc_wka_port *wka_port)
req->data = wka_port;
req->qtcb->header.port_handle = wka_port->handle;
+ req_id = req->req_id;
+
zfcp_fsf_start_timer(req, ZFCP_FSF_REQUEST_TIMEOUT);
retval = zfcp_fsf_req_send(req);
if (retval)
@@ -1713,7 +1719,7 @@ int zfcp_fsf_close_wka_port(struct zfcp_fc_wka_port *wka_port)
out:
spin_unlock_irq(&qdio->req_q_lock);
if (!retval)
- zfcp_dbf_rec_run_wka("fscwp_1", wka_port, req->req_id);
+ zfcp_dbf_rec_run_wka("fscwp_1", wka_port, req_id);
return retval;
}