diff mbox

scsi: fc: check for rport presence in fc_block_scsi_eh

Message ID 20170925120049.19689-1-jthumshirn@suse.de (mailing list archive)
State Superseded
Headers show

Commit Message

Johannes Thumshirn Sept. 25, 2017, noon UTC
Coverity-scan recently found a possible NULL pointer dereference in
fc_block_scsi_eh() as starget_to_rport() either returns the rport for
the startget or NULL.

While it is rather unlikely to have fc_block_scsi_eh() called without
an rport associated it's a good idea to catch potential misuses of the
API gracefully.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/scsi/scsi_transport_fc.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Bart Van Assche Sept. 25, 2017, 11:29 p.m. UTC | #1
On Mon, 2017-09-25 at 14:00 +0200, Johannes Thumshirn wrote:
> Coverity-scan recently found a possible NULL pointer dereference in

> fc_block_scsi_eh() as starget_to_rport() either returns the rport for

> the startget or NULL.

> 

> While it is rather unlikely to have fc_block_scsi_eh() called without

> an rport associated it's a good idea to catch potential misuses of the

> API gracefully.

> 

> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>

> ---

>  drivers/scsi/scsi_transport_fc.c | 3 +++

>  1 file changed, 3 insertions(+)

> 

> diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c

> index ba9d70f8a6a1..830ce53f30fb 100644

> --- a/drivers/scsi/scsi_transport_fc.c

> +++ b/drivers/scsi/scsi_transport_fc.c

> @@ -3328,6 +3328,9 @@ int fc_block_scsi_eh(struct scsi_cmnd *cmnd)

>  {

>  	struct fc_rport *rport = starget_to_rport(scsi_target(cmnd->device));

>  

> +	if (WARN_ON(!rport))

> +		return 0;

> +

>  	return fc_block_rport(rport);

>  }

>  EXPORT_SYMBOL(fc_block_scsi_eh);


Did you perhaps intend to use WARN_ON_ONCE() instead of WARN_ON()? Anyway:

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Johannes Thumshirn Sept. 26, 2017, 6:55 a.m. UTC | #2
On Mon, Sep 25, 2017 at 11:29:07PM +0000, Bart Van Assche wrote:
> Did you perhaps intend to use WARN_ON_ONCE() instead of WARN_ON()?

Now that you're saying it. I'll send a v2.

Thanks,
	Johannes
diff mbox

Patch

diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
index ba9d70f8a6a1..830ce53f30fb 100644
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -3328,6 +3328,9 @@  int fc_block_scsi_eh(struct scsi_cmnd *cmnd)
 {
 	struct fc_rport *rport = starget_to_rport(scsi_target(cmnd->device));
 
+	if (WARN_ON(!rport))
+		return 0;
+
 	return fc_block_rport(rport);
 }
 EXPORT_SYMBOL(fc_block_scsi_eh);