kernel.git/net/ipv4/ip_gre.c, branch linux-2.6.37.y

net: don't allow CAP_NET_ADMIN to load non-netdev kernel modules

2011-03-14T21:17:37Z

commit 8909c9ad8ff03611c9c96c9a92656213e4bb495b upstream. Since a8f80e8ff94ecba629542d9b4b5f5a8ee3eb565c any process with CAP_NET_ADMIN may load any module from /lib/modules/. This doesn't mean that CAP_NET_ADMIN is a superset of CAP_SYS_MODULE as modules are limited to /lib/modules/**. However, CAP_NET_ADMIN capability shouldn't allow anybody load any module not related to networking. This patch restricts an ability of autoloading modules to netdev modules with explicit aliases. This fixes CVE-2011-1019. Arnd Bergmann suggested to leave untouched the old pre-v2.6.32 behavior of loading netdev modules by name (without any prefix) for processes with CAP_SYS_MODULE to maintain the compatibility with network scripts that use autoloading netdev modules by aliases like "eth0", "wlan0". Currently there are only three users of the feature in the upstream kernel: ipip, ip_gre and sit. root@albatros:~# capsh --drop=$(seq -s, 0 11),$(seq -s, 13 34) -- root@albatros:~# grep Cap /proc/$$/status CapInh: 0000000000000000 CapPrm: fffffff800001000 CapEff: fffffff800001000 CapBnd: fffffff800001000 root@albatros:~# modprobe xfs FATAL: Error inserting xfs (/lib/modules/2.6.38-rc6-00001-g2bf4ca3/kernel/fs/xfs/xfs.ko): Operation not permitted root@albatros:~# lsmod | grep xfs root@albatros:~# ifconfig xfs xfs: error fetching interface information: Device not found root@albatros:~# lsmod | grep xfs root@albatros:~# lsmod | grep sit root@albatros:~# ifconfig sit sit: error fetching interface information: Device not found root@albatros:~# lsmod | grep sit root@albatros:~# ifconfig sit0 sit0 Link encap:IPv6-in-IPv4 NOARP MTU:1480 Metric:1 root@albatros:~# lsmod | grep sit sit 10457 0 tunnel4 2957 1 sit For CAP_SYS_MODULE module loading is still relaxed: root@albatros:~# grep Cap /proc/$$/status CapInh: 0000000000000000 CapPrm: ffffffffffffffff CapEff: ffffffffffffffff CapBnd: ffffffffffffffff root@albatros:~# ifconfig xfs xfs: error fetching interface information: Device not found root@albatros:~# lsmod | grep xfs xfs 745319 0 Reference: https://lkml.org/lkml/2011/2/24/203 Signed-off-by: Vasiliy Kulikov Signed-off-by: Michael Tokarev Acked-by: David S. Miller Acked-by: Kees Cook Signed-off-by: James Morris Signed-off-by: Greg Kroah-Hartman

ip_gre: fix fallback tunnel setup

2010-10-30T23:21:28Z

Before making the fallback tunnel visible to lookups, we should make sure it is completely setup, once ipgre_tunnel_init() had been called and tstats per_cpu pointer allocated. move rcu_assign_pointer(ign->tunnels_wc[0], tunnel); from ipgre_fb_tunnel_init() to ipgre_init_net() Based on a patch from Pavel Emelyanov Reported-by: Pavel Emelyanov Signed-off-by: Eric Dumazet Acked-by: Pavel Emelyanov Signed-off-by: David S. Miller

tunnels: Fix tunnels change rcu protection

2010-10-27T21:20:08Z

After making rcu protection for tunnels (ipip, gre, sit and ip6) a bug was introduced into the SIOCCHGTUNNEL code. The tunnel is first unlinked, then addresses change, then it is linked back probably into another bucket. But while changing the parms, the hash table is unlocked to readers and they can lookup the improper tunnel. Respective commits are b7285b79 (ipip: get rid of ipip_lock), 1507850b (gre: get rid of ipgre_lock), 3a43be3c (sit: get rid of ipip6_lock) and 94767632 (ip6tnl: get rid of ip6_tnl_lock). The quick fix is to wait for quiescent state to pass after unlinking, but if it is inappropriate I can invent something better, just let me know. Signed-off-by: Pavel Emelyanov Acked-by: Eric Dumazet Signed-off-by: David S. Miller

inet: RCU changes in inetdev_by_index()

2010-10-19T10:50:48Z

Convert inetdev_by_index() to not increment in_dev refcount. Callers hold RCU or RTNL, and should not decrement in_dev refcount. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: add a core netdev->rx_dropped counter

2010-10-05T21:47:55Z

In various situations, a device provides a packet to our stack and we drop it before it enters protocol stack : - softnet backlog full (accounted in /proc/net/softnet_stat) - bad vlan tag (not accounted) - unknown/unregistered protocol (not accounted) We can handle a per-device counter of such dropped frames at core level, and automatically adds it to the device provided stats (rx_dropped), so that standard tools can be used (ifconfig, ip link, cat /proc/net/dev) This is a generalization of commit 8990f468a (net: rx_dropped accounting), thus reverting it. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ip_gre: comments change

2010-09-30T06:35:10Z

HARD_TX_LOCK no longer protects tunnels from dead loops, but xmit_recursion percpu counter. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ip_gre: lockless xmit

2010-09-29T20:25:38Z

GRE tunnels can benefit from lockless xmits, using NETIF_F_LLTX Note: If tunnels are created with the "oseq" option, LLTX is not enabled : Even using an atomic_t o_seq, we would increase chance for packets being out of order at receiver. Bench on a 16 cpus machine (dual E5540 cpus), 16 threads sending 10000000 UDP frames via one gre tunnel (size:200 bytes per frame) Before patch : real 3m0.094s user 0m9.365s sys 47m50.103s After patch: real 0m29.756s user 0m11.097s sys 7m33.012s Last problem to solve is the contention on dst : 38660.00 21.4% __ip_route_output_key vmlinux 20786.00 11.5% dst_release vmlinux 14191.00 7.8% __xfrm_lookup vmlinux 12410.00 6.9% ip_finish_output vmlinux 4540.00 2.5% ip_push_pending_frames vmlinux 4427.00 2.4% ip_append_data vmlinux 4265.00 2.4% __alloc_skb vmlinux 4140.00 2.3% __ip_local_out vmlinux 3991.00 2.2% dev_queue_xmit vmlinux Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ip_gre: percpu stats accounting

2010-09-28T04:30:43Z

Le lundi 27 septembre 2010 à 14:29 +0100, Ben Hutchings a écrit : > > diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c > > index 5d6ddcb..de39b22 100644 > > --- a/net/ipv4/ip_gre.c > > +++ b/net/ipv4/ip_gre.c > [...] > > @@ -377,7 +405,7 @@ static struct ip_tunnel *ipgre_tunnel_locate(struct net *net, > > if (parms->name[0]) > > strlcpy(name, parms->name, IFNAMSIZ); > > else > > - sprintf(name, "gre%%d"); > > + strcpy(name, "gre%d"); > > > > dev = alloc_netdev(sizeof(*t), name, ipgre_tunnel_setup); > > if (!dev) > [...] > > This is a valid fix, but doesn't belong in this patch! > Sorry ? It was not a fix, but at most a cleanup ;) Anyway I forgot the gretap case... [PATCH 2/4 v2] ip_gre: percpu stats accounting Maintain per_cpu tx_bytes, tx_packets, rx_bytes, rx_packets. Other seldom used fields are kept in netdev->stats structure, possibly unsafe. This is a preliminary work to support lockless transmit path, and correct RX stats, that are already unsafe. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6

2010-09-27T08:03:03Z

Conflicts: drivers/net/qlcnic/qlcnic_init.c net/ipv4/ip_output.c

net: return operator cleanup

2010-09-23T21:33:39Z

Change "return (EXPR);" to "return EXPR;" return is not a function, parentheses are not required. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller