Date: Wed, 29 Nov 2017 09:40:11 +0000 (UTC) From: Hans Petter Selasky <hselasky@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r326362 - in head: share/man/man4 sys/net Message-ID: <201711290940.vAT9eBWV096246@repo.freebsd.org>
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Author: hselasky Date: Wed Nov 29 09:40:11 2017 New Revision: 326362 URL: https://svnweb.freebsd.org/changeset/base/326362 Log: Disallow TUN and TAP character device IOCTLs to modify the network device type to any value. This can cause page faults and panics due to accessing uninitialized fields in the "struct ifnet" which are specific to the network device type. MFC after: 1 week Found by: jau@iki.fi PR: 223767 Sponsored by: Mellanox Technologies Modified: head/share/man/man4/tap.4 head/share/man/man4/tun.4 head/sys/net/if_tap.c head/sys/net/if_tun.c Modified: head/share/man/man4/tap.4 ============================================================================== --- head/share/man/man4/tap.4 Wed Nov 29 09:18:24 2017 (r326361) +++ head/share/man/man4/tap.4 Wed Nov 29 09:40:11 2017 (r326362) @@ -1,7 +1,7 @@ .\" $FreeBSD$ .\" Based on PR#2411 .\" -.Dd April 10, 2015 +.Dd November 29, 2017 .Dt TAP 4 .Os .Sh NAME @@ -171,7 +171,14 @@ calls are supported .In net/if_tap.h ) : .Bl -tag -width VMIO_SIOCSETMACADDR .It Dv TAPSIFINFO -Set network interface information (line speed, MTU and type). +Set network interface information (line speed and MTU). +The type must be the same as returned by +.Dv TAPGIFINFO +or set to +.Dv IFT_ETHER +else the +.Xr ioctl 2 +call will fail. The argument should be a pointer to a .Va struct tapinfo . .It Dv TAPGIFINFO Modified: head/share/man/man4/tun.4 ============================================================================== --- head/share/man/man4/tun.4 Wed Nov 29 09:18:24 2017 (r326361) +++ head/share/man/man4/tun.4 Wed Nov 29 09:40:11 2017 (r326362) @@ -2,7 +2,7 @@ .\" $FreeBSD$ .\" Based on PR#2411 .\" -.Dd November 30, 2014 +.Dd November 29, 2017 .Dt TUN 4 .Os .Sh NAME @@ -208,8 +208,15 @@ this stores the internal debugging variable's value in .It Dv TUNSIFINFO The argument should be a pointer to an .Vt struct tuninfo -and allows setting the MTU, the type, and the baudrate of the tunnel +and allows setting the MTU and the baudrate of the tunnel device. +The type must be the same as returned by +.Dv TUNGIFINFO +or set to +.Dv IFT_PPP +else the +.Xr ioctl 2 +call will fail. The .Vt struct tuninfo is declared in Modified: head/sys/net/if_tap.c ============================================================================== --- head/sys/net/if_tap.c Wed Nov 29 09:18:24 2017 (r326361) +++ head/sys/net/if_tap.c Wed Nov 29 09:40:11 2017 (r326362) @@ -737,9 +737,10 @@ tapioctl(struct cdev *dev, u_long cmd, caddr_t data, i switch (cmd) { case TAPSIFINFO: tapp = (struct tapinfo *)data; + if (ifp->if_type != tapp->type) + return (EPROTOTYPE); mtx_lock(&tp->tap_mtx); ifp->if_mtu = tapp->mtu; - ifp->if_type = tapp->type; ifp->if_baudrate = tapp->baudrate; mtx_unlock(&tp->tap_mtx); break; Modified: head/sys/net/if_tun.c ============================================================================== --- head/sys/net/if_tun.c Wed Nov 29 09:18:24 2017 (r326361) +++ head/sys/net/if_tun.c Wed Nov 29 09:40:11 2017 (r326362) @@ -676,9 +676,10 @@ tunioctl(struct cdev *dev, u_long cmd, caddr_t data, i if (error) return (error); } + if (TUN2IFP(tp)->if_type != tunp->type) + return (EPROTOTYPE); mtx_lock(&tp->tun_mtx); TUN2IFP(tp)->if_mtu = tunp->mtu; - TUN2IFP(tp)->if_type = tunp->type; TUN2IFP(tp)->if_baudrate = tunp->baudrate; mtx_unlock(&tp->tun_mtx); break;
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