svn commit: r275035 - head/sys/i386/i386

[John Baldwin]

Author: jhb
Date: Tue Nov 25 12:52:00 2014
New Revision: 275035
URL: https://svnweb.freebsd.org/changeset/base/275035

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

Modified:
  head/sys/i386/i386/machdep.c

Modified: head/sys/i386/i386/machdep.c
==============================================================================
--- head/sys/i386/i386/machdep.c	Tue Nov 25 12:45:31 2014	(r275034)
+++ head/sys/i386/i386/machdep.c	Tue Nov 25 12:52:00 2014	(r275035)
@@ -1060,6 +1060,11 @@ 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) {
@@ -3858,7 +3863,8 @@ 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);