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authorAshutosh Dixit <ashutosh.dixit@intel.com>2016-04-27 14:36:05 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-04-27 15:30:58 -0700
commit82dc4afd7e65455464f0fc2fe6976efde54fe451 (patch)
tree8d84c648ca1e8f0684ac16435dfa9f5c91c30747 /drivers
parentc3b46c73264b03000d1e18b22f5caf63332547c9 (diff)
misc: mic: Fix for double fetch security bug in VOP driver
The MIC VOP driver does two successive reads from user space to read a variable length data structure. Kernel memory corruption can result if the data structure changes between the two reads. This patch disallows the chance of this happening. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=116651 Reported by: Pengfei Wang <wpengfeinudt@gmail.com> Reviewed-by: Sudeep Dutt <sudeep.dutt@intel.com> Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/misc/mic/vop/vop_vringh.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/misc/mic/vop/vop_vringh.c b/drivers/misc/mic/vop/vop_vringh.c
index e94c7fb6712a..88e45234d527 100644
--- a/drivers/misc/mic/vop/vop_vringh.c
+++ b/drivers/misc/mic/vop/vop_vringh.c
@@ -945,6 +945,11 @@ static long vop_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
ret = -EFAULT;
goto free_ret;
}
+ /* Ensure desc has not changed between the two reads */
+ if (memcmp(&dd, dd_config, sizeof(dd))) {
+ ret = -EINVAL;
+ goto free_ret;
+ }
mutex_lock(&vdev->vdev_mutex);
mutex_lock(&vi->vop_mutex);
ret = vop_virtio_add_device(vdev, dd_config);

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