3.16.37-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Ashutosh Dixit <ashutosh.di...@intel.com> 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 <wpengfein...@gmail.com> Reviewed-by: Sudeep Dutt <sudeep.d...@intel.com> Signed-off-by: Ashutosh Dixit <ashutosh.di...@intel.com> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> [bwh: Backported to 3.16: - Adjust filename, context - goto exit on failure] Signed-off-by: Ben Hutchings <b...@decadent.org.uk> --- drivers/misc/mic/host/mic_virtio.c | 5 +++++ 1 file changed, 5 insertions(+) --- 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_ __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++) {
