Use unsigned int for index value.

Without this change a local attacker could trigger a panic by
tricking the kernel into accessing undefined kernel memory.

We would like to acknowledge Francisco Falcon from CORE Security
Technologies who discovered the issue and reported to the
FreeBSD Security Team.

More information can be found at CORE Security's advisory at:
http://www.coresecurity.com/content/freebsd-kernel-multiple-vulnerabilities

This is an errata candidate for releng/10.1 and releng/9.3.  Earlier
releases are not affected.

Reported by:	Francisco Falcon from CORE Security Technologies
Security:	CVE-2014-0998
Reviewed by:	dumbbell
MFC after:	3 days
This commit is contained in:
Xin LI 2015-01-27 19:35:41 +00:00
parent 6a58f0e913
commit 9049b13f8f
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=277806

View File

@ -2367,20 +2367,23 @@ vtterm_ioctl(struct terminal *tm, u_long cmd, caddr_t data,
}
VT_UNLOCK(vd);
return (EINVAL);
case VT_WAITACTIVE:
case VT_WAITACTIVE: {
unsigned int idx;
error = 0;
i = *(unsigned int *)data;
if (i > VT_MAXWINDOWS)
idx = *(unsigned int *)data;
if (idx > VT_MAXWINDOWS)
return (EINVAL);
if (i != 0)
vw = vd->vd_windows[i - 1];
if (idx > 0)
vw = vd->vd_windows[idx - 1];
VT_LOCK(vd);
while (vd->vd_curwindow != vw && error == 0)
error = cv_wait_sig(&vd->vd_winswitch, &vd->vd_lock);
VT_UNLOCK(vd);
return (error);
}
case VT_SETMODE: { /* set screen switcher mode */
struct vt_mode *mode;
struct proc *p1;