[PATCH 3.4 32/35] SCSI: storvsc: NULL pointer dereference fix

Greg Kroah-Hartman
2014-03-21T00:10:06Z

From: Ales Novak <alnovak@suse.cz>

commit b12bb60d6c350b348a4e1460cd68f97ccae9822e upstream.

If the initialization of storvsc fails, the storvsc_device_destroy()
causes NULL pointer dereference.

storvsc_bus_scan()
scsi_scan_target()
__scsi_scan_target()
scsi_probe_and_add_lun(hostdata=NULL)
scsi_alloc_sdev(hostdata=NULL)

sdev->hostdata = hostdata

now the host allocation fails

__scsi_remove_device(sdev)

calls sdev->host->hostt->slave_destroy() ==
storvsc_device_destroy(sdev)
access of sdev->hostdata->request_mempool

Signed-off-by: Ales Novak <alnovak@suse.cz>
Signed-off-by: Thomas Abraham <tabraham@suse.com>
Reviewed-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/scsi/storvsc_drv.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1131,6 +1131,9 @@ static void storvsc_device_destroy(struc
{
struct stor_mem_pools *memp = sdevice->hostdata;

+ if (!memp)
+ return;
+
mempool_destroy(memp->request_mempool);
kmem_cache_destroy(memp->request_pool);
kfree(memp);