diff options
| author | Ashutosh Dixit <ashutosh.dixit@intel.com> | 2016-04-27 14:36:05 -0700 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2016-08-22 22:38:29 +0100 |
| commit | 72aaf646fb6b6f8f7befb44cbd5b1acd3bb5b483 (patch) | |
| tree | 370d8908f63390afda419a9ba0422d840446ff0d | |
| parent | c6287499662db0b0caee72d6453e445a2c6162af (diff) | |
misc: mic: Fix for double fetch security bug in VOP driver
commit 9bf292bfca94694a721449e3fd752493856710f6 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16:
- Adjust filename, context
- goto exit on failure]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | drivers/misc/mic/host/mic_virtio.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/misc/mic/host/mic_virtio.c b/drivers/misc/mic/host/mic_virtio.c index 7e1ef0ebbb80..dba3c19929db 100644 --- a/drivers/misc/mic/host/mic_virtio.c +++ b/drivers/misc/mic/host/mic_virtio.c @@ -456,6 +456,11 @@ static int mic_copy_dp_entry(struct mic_vdev *mvdev, __func__, __LINE__, ret); goto exit; } + /* Ensure desc has not changed between the two reads */ + if (memcmp(&dd, dd_config, sizeof(dd))) { + ret = -EINVAL; + goto exit; + } vqconfig = mic_vq_config(dd_config); for (i = 0; i < dd.num_vq; i++) { |