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| author | Steffen Maier <maier@linux.vnet.ibm.com> | 2011-11-18 20:00:40 +0100 |
|---|---|---|
| committer | James Bottomley <JBottomley@Parallels.com> | 2011-12-14 15:40:43 +0400 |
| commit | 44f747fff6e9f027a4866c1a6864e26ae7c510c8 (patch) | |
| tree | bbaf28b480018835fb61db1dd13ce8bd4d4e8b97 /drivers/s390/scsi | |
| parent | 7e1e7ead88dff75b11b86ee0d5232c4591be1326 (diff) | |
| download | linux-44f747fff6e9f027a4866c1a6864e26ae7c510c8.tar.gz linux-44f747fff6e9f027a4866c1a6864e26ae7c510c8.tar.bz2 linux-44f747fff6e9f027a4866c1a6864e26ae7c510c8.zip | |
[SCSI] zfcp: return early from slave_destroy if slave_alloc returned early
zfcp_scsi_slave_destroy erroneously always tried to finish its task
even if the corresponding previous zfcp_scsi_slave_alloc returned
early. This can lead to kernel page faults on accessing uninitialized
fields of struct zfcp_scsi_dev in zfcp_erp_lun_shutdown_wait. Take the
port field of the struct to determine if slave_alloc returned early.
This zfcp bug is exposed by 4e6c82b (in turn fixing f7c9c6b to be
compatible with 21208ae) which can call slave_destroy for a
corresponding previous slave_alloc that did not finish.
This patch is based on James Bottomley's fix suggestion in
http://www.spinics.net/lists/linux-scsi/msg55449.html.
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Cc: <stable@kernel.org> #2.6.38+
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/s390/scsi')
| -rw-r--r-- | drivers/s390/scsi/zfcp_scsi.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c index 11f07f888223..b79576b64f45 100644 --- a/drivers/s390/scsi/zfcp_scsi.c +++ b/drivers/s390/scsi/zfcp_scsi.c @@ -55,6 +55,10 @@ static void zfcp_scsi_slave_destroy(struct scsi_device *sdev) { struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev); + /* if previous slave_alloc returned early, there is nothing to do */ + if (!zfcp_sdev->port) + return; + zfcp_erp_lun_shutdown_wait(sdev, "scssd_1"); put_device(&zfcp_sdev->port->dev); } |