> sizeof(__u8) is by definition 1 so it's perhaps surplus ? Now the size is now determined from the structure definition in include/uapi/linux/hyperv.h > - C style comments for coding style Fixed > Also your patch block is devoid of a few thins like the file name... I'm sorry, the (missing) filename mistake occured in copy-paste process. Here is the patch as it (I hope) should look like: --- From: Matej Mužila <mmuzila@xxxxxxxxxx> Check if cpmsg->size is in limits of DATA_FRAGMENT Signed-off-by: Matej Mužila <mmuzila@xxxxxxxxxx> --- If corrupted data are read from /dev/vmbus/hv_fcopy, pwrite can read from memory outside of the buffer (defined at line 138). Added check. --- diff --git a/tools/hv/hv_fcopy_daemon.c b/tools/hv/hv_fcopy_daemon.c index 6f27e2f..1fc2dc2 100644 --- a/tools/hv/hv_fcopy_daemon.c +++ b/tools/hv/hv_fcopy_daemon.c @@ -104,6 +104,10 @@ static int hv_copy_data(struct hv_do_fcopy *cpmsg) { ssize_t bytes_written; + /* Check if the cpmsg->size is in limits of DATA_FRAGMENT */ + if (cpmsg->size > sizeof(cpmsg->data)) + return HV_E_FAIL; + bytes_written = pwrite(target_fd, cpmsg->data, cpmsg->size, cpmsg->offset); _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel