svn commit: r332034 - head/sys/compat/linux

[Ed Maste]

Author: emaste
Date: Wed Apr  4 14:41:48 2018
New Revision: 332034
URL: https://svnweb.freebsd.org/changeset/base/332034

Log:
  linux_ioctl_hdio: fix kernel memory disclosure
  
  Stack-allocated struct linux_hd_big_geometry has undeclared padding
  copied to userland.
  
  admbugs:	765
  Reported by:	Vlad Tsyrklevich
  MFC after:	1 day
  Security:	Kernel memory disclosure
  Sponsored by:	The FreeBSD Foundation

Modified:
  head/sys/compat/linux/linux_ioctl.c

Modified: head/sys/compat/linux/linux_ioctl.c
==============================================================================
--- head/sys/compat/linux/linux_ioctl.c	Wed Apr  4 14:31:56 2018	(r332033)
+++ head/sys/compat/linux/linux_ioctl.c	Wed Apr  4 14:41:48 2018	(r332034)
@@ -253,6 +253,7 @@ linux_ioctl_hdio(struct thread *td, struct linux_ioctl
 		} else if ((args->cmd & 0xffff) == LINUX_HDIO_GET_GEO_BIG) {
 			struct linux_hd_big_geometry hdbg;
 
+			memset(&hdbg, 0, sizeof(hdbg));
 			hdbg.cylinders = fwcylinders;
 			hdbg.heads = fwheads;
 			hdbg.sectors = fwsectors;