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authorMichael S. Tsirkin <mst@redhat.com>2012-08-18 15:44:09 -0700
committerNicholas Bellinger <nab@linux-iscsi.org>2012-08-20 14:52:11 -0700
commit6de7145ca3db231a84b7516a6cb25878da6ebb19 (patch)
tree3958d4cf730acc08fb9f9f1ad3be4cb132eca17e /drivers/vhost
parent74f4cf290918f05b6489aa732dfb08aa5606b9d6 (diff)
downloadlinux-linaro-stable-6de7145ca3db231a84b7516a6cb25878da6ebb19.tar.gz
tcm_vhost: Fix vhost_scsi_target structure alignment
Here TRANSPORT_IQN_LEN is 224, which is a multiple of 4. Since vhost_tpgt is 2 bytes and abi_version is 4, the total size would be 230. But gcc needs struct size be aligned to first field size, which is 4 bytes, so it pads the structure by extra 2 bytes to the total of 232. This padding is very undesirable in an ABI: - it can not be initialized easily - it can not be checked easily - it can leak information between kernel and userspace Simplest solution is probably just to make the padding explicit. (v2: Add check for zero'ed backend->reserved field for VHOST_SCSI_SET_ENDPOINT and VHOST_SCSI_CLEAR_ENDPOINT ops as requested by MST) Reported-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/vhost')
-rw-r--r--drivers/vhost/tcm_vhost.c4
-rw-r--r--drivers/vhost/tcm_vhost.h1
2 files changed, 5 insertions, 0 deletions
diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c
index 74b2edaaf1f6..ed8e2e6c8df2 100644
--- a/drivers/vhost/tcm_vhost.c
+++ b/drivers/vhost/tcm_vhost.c
@@ -995,11 +995,15 @@ static long vhost_scsi_ioctl(struct file *f, unsigned int ioctl,
case VHOST_SCSI_SET_ENDPOINT:
if (copy_from_user(&backend, argp, sizeof backend))
return -EFAULT;
+ if (backend.reserved != 0)
+ return -EOPNOTSUPP;
return vhost_scsi_set_endpoint(vs, &backend);
case VHOST_SCSI_CLEAR_ENDPOINT:
if (copy_from_user(&backend, argp, sizeof backend))
return -EFAULT;
+ if (backend.reserved != 0)
+ return -EOPNOTSUPP;
return vhost_scsi_clear_endpoint(vs, &backend);
case VHOST_SCSI_GET_ABI_VERSION:
diff --git a/drivers/vhost/tcm_vhost.h b/drivers/vhost/tcm_vhost.h
index e9d5c020fb39..d9e93557d669 100644
--- a/drivers/vhost/tcm_vhost.h
+++ b/drivers/vhost/tcm_vhost.h
@@ -93,6 +93,7 @@ struct vhost_scsi_target {
int abi_version;
char vhost_wwpn[TRANSPORT_IQN_LEN];
unsigned short vhost_tpgt;
+ unsigned short reserved;
};
/* VHOST_SCSI specific defines */