svn commit: r276085 - stable/10/sys/i386/i386

[John Baldwin]

Author: jhb
Date: Mon Dec 22 21:46:35 2014
New Revision: 276085
URL: https://svnweb.freebsd.org/changeset/base/276085

Log:
  MFC 275035:
  MFamd64: Check for invalid flags in the machine context in sigreturn()
  and setcontext().

Modified:
  stable/10/sys/i386/i386/machdep.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/i386/i386/machdep.c
==============================================================================
--- stable/10/sys/i386/i386/machdep.c	Mon Dec 22 21:32:39 2014	(r276084)
+++ stable/10/sys/i386/i386/machdep.c	Mon Dec 22 21:46:35 2014	(r276085)
@@ -1043,6 +1043,11 @@ sys_sigreturn(td, uap)
 	if (error != 0)
 		return (error);
 	ucp = &uc;
+	if ((ucp->uc_mcontext.mc_flags & ~_MC_FLAG_MASK) != 0) {
+		uprintf("pid %d (%s): sigreturn mc_flags %x\n", p->p_pid,
+		    td->td_name, ucp->uc_mcontext.mc_flags);
+		return (EINVAL);
+	}
 	regs = td->td_frame;
 	eflags = ucp->uc_mcontext.mc_eflags;
 	if (eflags & PSL_VM) {
@@ -3540,7 +3545,8 @@ set_mcontext(struct thread *td, const mc
 	int eflags, ret;
 
 	tp = td->td_frame;
-	if (mcp->mc_len != sizeof(*mcp))
+	if (mcp->mc_len != sizeof(*mcp) ||
+	    (mcp->mc_flags & ~_MC_FLAG_MASK) != 0)
 		return (EINVAL);
 	eflags = (mcp->mc_eflags & PSL_USERCHANGE) |
 	    (tp->tf_eflags & ~PSL_USERCHANGE);