diff options
| author | Steffen Maier <maier@linux.vnet.ibm.com> | 2017-02-08 15:34:22 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-02-14 15:22:52 -0800 |
| commit | 52e02d6bf304c73d000f7b3f1448d50c08b0befc (patch) | |
| tree | bcf3ccbcaedf4bea1c5326f10a1a2221db6a8183 | |
| parent | f2d256a2d49f535dcd9e1aad09f96ef0add706d2 (diff) | |
scsi: zfcp: fix use-after-free by not tracing WKA port open/close on failed send
commit 2dfa6688aafdc3f74efeb1cf05fb871465d67f79 upstream.
Dan Carpenter kindly reported:
<quote>
The patch d27a7cb91960: "zfcp: trace on request for open and close of
WKA port" from Aug 10, 2016, leads to the following static checker
warning:
drivers/s390/scsi/zfcp_fsf.c:1615 zfcp_fsf_open_wka_port()
warn: 'req' was already freed.
drivers/s390/scsi/zfcp_fsf.c
1609 zfcp_fsf_start_timer(req, ZFCP_FSF_REQUEST_TIMEOUT);
1610 retval = zfcp_fsf_req_send(req);
1611 if (retval)
1612 zfcp_fsf_req_free(req);
^^^
Freed.
1613 out:
1614 spin_unlock_irq(&qdio->req_q_lock);
1615 if (req && !IS_ERR(req))
1616 zfcp_dbf_rec_run_wka("fsowp_1", wka_port, req->req_id);
^^^^^^^^^^^
Use after free.
1617 return retval;
1618 }
Same thing for zfcp_fsf_close_wka_port() as well.
</quote>
Rather than relying on req being NULL (or ERR_PTR) for all cases where
we don't want to trace or should not trace,
simply check retval which is unconditionally initialized with -EIO != 0
and it can only become 0 on successful retval = zfcp_fsf_req_send(req).
With that we can also remove the then again unnecessary unconditional
initialization of req which was introduced with that earlier commit.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Suggested-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: d27a7cb91960 ("zfcp: trace on request for open and close of WKA port")
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/s390/scsi/zfcp_fsf.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c index 75f820ca17b7..27ff38f839fc 100644 --- a/drivers/s390/scsi/zfcp_fsf.c +++ b/drivers/s390/scsi/zfcp_fsf.c @@ -1583,7 +1583,7 @@ out: 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 = NULL; + struct zfcp_fsf_req *req; int retval = -EIO; spin_lock_irq(&qdio->req_q_lock); @@ -1612,7 +1612,7 @@ int zfcp_fsf_open_wka_port(struct zfcp_fc_wka_port *wka_port) zfcp_fsf_req_free(req); out: spin_unlock_irq(&qdio->req_q_lock); - if (req && !IS_ERR(req)) + if (!retval) zfcp_dbf_rec_run_wka("fsowp_1", wka_port, req->req_id); return retval; } @@ -1638,7 +1638,7 @@ static void zfcp_fsf_close_wka_port_handler(struct zfcp_fsf_req *req) 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 = NULL; + struct zfcp_fsf_req *req; int retval = -EIO; spin_lock_irq(&qdio->req_q_lock); @@ -1667,7 +1667,7 @@ int zfcp_fsf_close_wka_port(struct zfcp_fc_wka_port *wka_port) zfcp_fsf_req_free(req); out: spin_unlock_irq(&qdio->req_q_lock); - if (req && !IS_ERR(req)) + if (!retval) zfcp_dbf_rec_run_wka("fscwp_1", wka_port, req->req_id); return retval; } |