kernel.git/net/ipv6/sit.c, branch linux-2.6.33.y

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

2011-03-21T19:45:36Z

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

net: Simplify ipip6 aka sit pernet operations.

2009-12-02T00:15:59Z

Take advantage of the new pernet automatic storage management, and stop using compatibility network namespace functions. Signed-off-by: Eric W. Biederman Signed-off-by: David S. Miller

netns: net_identifiers should be read_mostly

2009-11-18T13:03:25Z

Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

sit: Clean up DF code by copying from IPIP

2009-11-11T04:54:43Z

This patch rearranges the SIT DF bit handling using the new IPIP DF code. The only externally visible effect should be the case where PMTU is enabled and the MTU is exactly 1280 bytes. In this case the previous code would send packets out with DF off while the new code would set the DF bit. This is inline with RFC 4213. Signed-off-by: Herbert Xu Thanks, Signed-off-by: David S. Miller

ipv6 sit: Optimize multiple unregistration

2009-10-29T08:13:51Z

Speedup module unloading by factorizing synchronize_rcu() calls Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ipv6 sit: RCU conversion phase II

2009-10-24T13:07:56Z

SIT tunnels use one rwlock to protect their hash tables. This locking scheme can be converted to RCU for free, since netdevice already must wait for a RCU grace period at dismantle time. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ipv6 sit: RCU conversion phase I

2009-10-24T13:07:55Z

SIT tunnels use one rwlock to protect their prl entries. This first patch adds RCU locking for prl management, with standard call_rcu() calls. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ipv6 sit: Set relay to 0.0.0.0 directly if relay_prefixlen == 0.

2009-10-12T06:41:10Z

ipv6 sit: Set relay to 0.0.0.0 directly if relay_prefixlen == 0. Do not use bit-shift if relay_prefixlen == 0; relay_prefix << 32 does not result in 0. Signed-off-by: YOSHIFUJI Hideaki Signed-off-by: David S. Miller

ipv6 sit: Fix 6rd relay address.

2009-10-12T06:41:08Z

ipv6 sit: Fix 6rd relay address. Relay's address should be extracted from real IPv6 address instead of configured prefix. Signed-off-by: YOSHIFUJI Hideaki Signed-off-by: David S. Miller

ipv6 sit: Ensure to initialize 6rd parameters.

2009-10-12T06:41:07Z

ipv6 sit: Ensure to initialize 6rd parameters. Signed-off-by: YOSHIFUJI Hideaki Signed-off-by: David S. Miller