svn commit: r360705 - stable/11/sys/kern
Michael Tuexen
tuexen at FreeBSD.org
Wed May 6 21:59:59 UTC 2020
Author: tuexen
Date: Wed May 6 21:59:58 2020
New Revision: 360705
URL: https://svnweb.freebsd.org/changeset/base/360705
Log:
MFC r349989: Improve input validation for l_linger
When using the SOL_SOCKET level socket option SO_LINGER, the structure
struct linger is used as the option value. The component l_linger is of
type int, but internally copied to the field so_linger of the structure
struct socket. The type of so_linger is short, but it is assumed to be
non-negative and the value is used to compute ticks to be stored in a
variable of type int.
Therefore, perform input validation on l_linger similar to the one
performed by NetBSD and OpenBSD.
Thanks to syzkaller for making me aware of this issue.
Thanks to markj@ for pointing out that a similar check should be added
to so_linger_set().
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D20948
Modified:
stable/11/sys/kern/uipc_socket.c
Directory Properties:
stable/11/ (props changed)
Modified: stable/11/sys/kern/uipc_socket.c
==============================================================================
--- stable/11/sys/kern/uipc_socket.c Wed May 6 19:58:37 2020 (r360704)
+++ stable/11/sys/kern/uipc_socket.c Wed May 6 21:59:58 2020 (r360705)
@@ -2535,7 +2535,12 @@ sosetopt(struct socket *so, struct sockopt *sopt)
error = sooptcopyin(sopt, &l, sizeof l, sizeof l);
if (error)
goto bad;
-
+ if (l.l_linger < 0 ||
+ l.l_linger > USHRT_MAX ||
+ l.l_linger > (INT_MAX / hz)) {
+ error = EDOM;
+ goto bad;
+ }
SOCK_LOCK(so);
so->so_linger = l.l_linger;
if (l.l_onoff)
@@ -3701,6 +3706,9 @@ so_linger_get(const struct socket *so)
void
so_linger_set(struct socket *so, int val)
{
+
+ KASSERT(val >= 0 && val <= USHRT_MAX && val <= (INT_MAX / hz),
+ ("%s: val %d out of range", __func__, val));
so->so_linger = val;
}
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