IB/hfi1: Split copy_to_user data copy for better security

A copy_to_user() call assumes that two members of a data structure
are sequential.  Since this may not always be true, separate the copies
to ensure a safe copy.

Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Michael J. Ruhl 2017-07-24 07:46:42 -07:00 committed by Doug Ledford
parent 5e2d6764a7
commit f13a6e5e2e

View File

@ -268,12 +268,14 @@ static long hfi1_file_ioctl(struct file *fp, unsigned int cmd,
/*
* Copy the number of tidlist entries we used
* and the length of the buffer we registered.
* These fields are adjacent in the structure so
* we can copy them at the same time.
*/
addr = arg + offsetof(struct hfi1_tid_info, tidcnt);
if (copy_to_user((void __user *)addr, &tinfo.tidcnt,
sizeof(tinfo.tidcnt) +
sizeof(tinfo.tidcnt)))
return -EFAULT;
addr = arg + offsetof(struct hfi1_tid_info, length);
if (copy_to_user((void __user *)addr, &tinfo.length,
sizeof(tinfo.length)))
ret = -EFAULT;
}