linux/net/ipv6
Arnaud Ebalard 9a732ed6d0 netfilter: {nfnetlink,ip,ip6}_queue: fix skb_over_panic when enlarging packets
While reinjecting *bigger* modified versions of IPv6 packets using
libnetfilter_queue, things work fine on a 2.6.24 kernel (2.6.22 too)
but I get the following on recents kernels (2.6.25, trace below is
against today's net-2.6 git tree):

skb_over_panic: text:c04fddb0 len:696 put:632 head:f7592c00 data:f7592c00 tail:0xf7592eb8 end:0xf7592e80 dev:eth0
------------[ cut here ]------------
invalid opcode: 0000 [#1] PREEMPT 
Process sendd (pid: 3657, ti=f6014000 task=f77c31d0 task.ti=f6014000)
Stack: c071e638 c04fddb0 000002b8 00000278 f7592c00 f7592c00 f7592eb8 f7592e80 
       f763c000 f6bc5200 f7592c40 f6015c34 c04cdbfc f6bc5200 00000278 f6015c60 
       c04fddb0 00000020 f72a10c0 f751b420 00000001 0000000a 000002b8 c065582c 
Call Trace:
 [<c04fddb0>] ? nfqnl_recv_verdict+0x1c0/0x2e0
 [<c04cdbfc>] ? skb_put+0x3c/0x40
 [<c04fddb0>] ? nfqnl_recv_verdict+0x1c0/0x2e0
 [<c04fd115>] ? nfnetlink_rcv_msg+0xf5/0x160
 [<c04fd03e>] ? nfnetlink_rcv_msg+0x1e/0x160
 [<c04fd020>] ? nfnetlink_rcv_msg+0x0/0x160
 [<c04f8ed7>] ? netlink_rcv_skb+0x77/0xa0
 [<c04fcefc>] ? nfnetlink_rcv+0x1c/0x30
 [<c04f8c73>] ? netlink_unicast+0x243/0x2b0
 [<c04cfaba>] ? memcpy_fromiovec+0x4a/0x70
 [<c04f9406>] ? netlink_sendmsg+0x1c6/0x270
 [<c04c8244>] ? sock_sendmsg+0xc4/0xf0
 [<c011970d>] ? set_next_entity+0x1d/0x50
 [<c0133a80>] ? autoremove_wake_function+0x0/0x40
 [<c0118f9e>] ? __wake_up_common+0x3e/0x70
 [<c0342fbf>] ? n_tty_receive_buf+0x34f/0x1280
 [<c011d308>] ? __wake_up+0x68/0x70
 [<c02cea47>] ? copy_from_user+0x37/0x70
 [<c04cfd7c>] ? verify_iovec+0x2c/0x90
 [<c04c837a>] ? sys_sendmsg+0x10a/0x230
 [<c011967a>] ? __dequeue_entity+0x2a/0xa0
 [<c011970d>] ? set_next_entity+0x1d/0x50
 [<c0345397>] ? pty_write+0x47/0x60
 [<c033d59b>] ? tty_default_put_char+0x1b/0x20
 [<c011d2e9>] ? __wake_up+0x49/0x70
 [<c033df99>] ? tty_ldisc_deref+0x39/0x90
 [<c033ff20>] ? tty_write+0x1a0/0x1b0
 [<c04c93af>] ? sys_socketcall+0x7f/0x260
 [<c0102ff9>] ? sysenter_past_esp+0x6a/0x91
 [<c05f0000>] ? snd_intel8x0m_probe+0x270/0x6e0
 =======================
Code: 00 00 89 5c 24 14 8b 98 9c 00 00 00 89 54 24 0c 89 5c 24 10 8b 40 50 89 4c 24 04 c7 04 24 38 e6 71 c0 89 44 24 08 e8 c4 46 c5 ff <0f> 0b eb fe 55 89 e5 56 89 d6 53 89 c3 83 ec 0c 8b 40 50 39 d0 
EIP: [<c04ccdfc>] skb_over_panic+0x5c/0x60 SS:ESP 0068:f6015bf8


Looking at the code, I ended up in nfq_mangle() function (called by
nfqnl_recv_verdict()) which performs a call to skb_copy_expand() due to
the increased size of data passed to the function. AFAICT, it should ask
for 'diff' instead of 'diff - skb_tailroom(e->skb)'. Because the
resulting sk_buff has not enough space to support the skb_put(skb, diff)
call a few lines later, this results in the call to skb_over_panic().

The patch below asks for allocation of a copy with enough space for
mangled packet and the same amount of headroom as old sk_buff. While
looking at how the regression appeared (e2b58a67), I noticed the same
pattern in ipq_mangle_ipv6() and ipq_mangle_ipv4(). The patch corrects
those locations too.

Tested with bigger reinjected IPv6 packets (nfqnl_mangle() path), things
are ok (2.6.25 and today's net-2.6 git tree).

Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-29 03:16:34 -07:00
..
netfilter netfilter: {nfnetlink,ip,ip6}_queue: fix skb_over_panic when enlarging packets 2008-04-29 03:16:34 -07:00
addrconf_core.c [IPV6]: ipv6_addr_type() doesn't know about RFC4193 addresses. 2007-07-31 02:28:21 -07:00
addrconf.c [NETNS]: Remove empty ->init callback. 2008-04-21 14:33:16 -07:00
addrlabel.c [NET] NETNS: Omit sock->sk_net without CONFIG_NET_NS. 2008-03-26 04:39:55 +09:00
af_inet6.c [IPV6] MROUTE: Support multicast forwarding. 2008-04-05 22:33:38 +09:00
ah6.c [IPSEC]: Fix bogus usage of u64 on input sequence number 2008-02-12 22:50:35 -08:00
anycast.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2008-04-14 02:30:23 -07:00
datagram.c [NETNS][IPV6]: inet6_addr - check ipv6 address per namespace 2008-01-28 15:01:44 -08:00
esp6.c [ESP]: Ensure IV is in linear part of the skb to avoid BUG() due to OOB access 2008-03-27 16:08:03 -07:00
exthdrs_core.c [NET] IPV6: Fix whitespace errors. 2007-02-10 23:19:42 -08:00
exthdrs.c [NETNS][IPV6]: inet6_addr - make ipv6_chk_home_addr namespace aware 2008-01-28 15:01:46 -08:00
fib6_rules.c [IPV6] FIB_RULE: Sparse: fib6_rules_cleanup() is of void. 2008-04-11 19:47:53 +09:00
icmp.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2008-04-14 02:30:23 -07:00
inet6_connection_sock.c [SOCK]: Add some notes about per-bind-bucket sock lookup. 2008-04-14 02:42:27 -07:00
inet6_hashtables.c [SOCK][NETNS]: Add a struct net argument to sock_prot_inuse_add and _get. 2008-03-31 19:41:46 -07:00
ip6_fib.c [NETNS]: The ip6_fib_timer can work with garbage on net namespace stop. 2008-04-21 14:23:03 -07:00
ip6_flowlabel.c [NETNS][IPV6] flowlabels - make proc per namespace 2008-03-26 16:53:30 -07:00
ip6_input.c [IPV6]: Kill several warnings without CONFIG_IPV6_MROUTE. 2008-04-11 19:47:49 +09:00
ip6_output.c [IPV6]: Make address arguments const. 2008-04-12 13:43:18 +09:00
ip6_tunnel.c [IP6TUNNEL]: Allow to create IP6 tunnels in net namespaces. 2008-04-16 01:24:13 -07:00
ip6mr.c ipv6: result of csum_fold() is already 16bit, no need to cast 2008-04-27 14:26:49 -07:00
ipcomp6.c [IPCOMP]: Disable BH on output when using shared tfm 2008-02-28 11:23:17 -08:00
ipv6_sockglue.c ipv4/ipv6 compat: Fix SSM applications on 64bit kernels. 2008-04-27 14:26:53 -07:00
Kconfig Revert "ipv6: Fix typo in net/ipv6/Kconfig" 2008-04-27 14:26:50 -07:00
Makefile [IPV6] MROUTE: Support multicast forwarding. 2008-04-05 22:33:38 +09:00
mcast.c [IPV6]: Use in6addr_any where appropriate. 2008-04-12 13:43:20 +09:00
mip6.c [IPV6] MIP6: Use our standard definitions for paddings. 2008-04-12 13:43:22 +09:00
ndisc.c [IPV6]: Define constants for link-local multicast addresses. 2008-04-12 13:43:19 +09:00
netfilter.c [NETFILTER]: Add partial checksum validation helper 2008-04-14 11:15:49 +02:00
proc.c [IPV6][NETNS]: Display per-net info in sockstat6 file. 2008-03-31 19:43:43 -07:00
protocol.c [IPV6]: Decentralize EXPORT_SYMBOLs. 2007-04-25 22:23:36 -07:00
raw.c ipv6 RAW: Disallow IPPROTO_IPV6-level IPV6_CHECKSUM socket option on ICMPv6 sockets. 2008-04-24 21:30:38 -07:00
reassembly.c [NET]: Rename inet_frag.h identifiers COMPLETE, FIRST_IN, LAST_IN to INET_FRAG_* 2008-03-28 16:35:27 -07:00
route.c [NETNS]: Don't initialize err variable twice. 2008-04-21 14:25:23 -07:00
sit.c [SIT]: Allow to create SIT tunnels in net namespaces. 2008-04-16 01:17:18 -07:00
syncookies.c [Syncookies]: Add support for TCP options via timestamps. 2008-04-10 03:12:40 -07:00
sysctl_net_ipv6.c [IPV6] SYSCTL: complete initialization for sysctl table in subsystem code. 2008-03-04 15:18:23 +09:00
tcp_ipv6.c [INET]: Drop the inet_inherit_port() call. 2008-04-17 23:17:34 -07:00
tunnel6.c [IPV6]: Replace sk_buff ** with sk_buff * in input handlers 2007-10-15 12:50:28 -07:00
udp_impl.h [UDP]: Make full use of proto.h.udp_hash innovation. 2008-03-22 16:51:21 -07:00
udp.c [IPv6]: Change IPv6 unspecified destination address to ::1 for raw and un-connected sockets 2008-04-12 13:43:27 +09:00
udplite.c [UDP]: Remove owner from udp_seq_afinfo. 2008-03-28 18:25:53 -07:00
xfrm6_input.c [XFRM] IPV6: Optimize xfrm6_input_addr(). 2008-03-25 10:23:56 +09:00
xfrm6_mode_beet.c [IPSEC]: Fix BEET output 2008-03-26 16:51:09 -07:00
xfrm6_mode_ro.c [IPSEC]: Make x->lastused an unsigned long 2008-01-28 14:53:52 -08:00
xfrm6_mode_transport.c [IPSEC]: Use IPv6 calling convention as the convention for x->mode->output 2007-10-10 16:55:54 -07:00
xfrm6_mode_tunnel.c [IPSEC]: Fix inter address family IPsec tunnel handling. 2008-03-24 14:51:51 -07:00
xfrm6_output.c [IPSEC]: Fix inter address family IPsec tunnel handling. 2008-03-24 14:51:51 -07:00
xfrm6_policy.c [NET] NETNS: Omit net_device->nd_net without CONFIG_NET_NS. 2008-03-26 04:39:53 +09:00
xfrm6_state.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2008-03-27 18:48:56 -07:00
xfrm6_tunnel.c [XFRM] IPV6: Optimize __xfrm_tunnel_alloc_spi(). 2008-03-25 10:23:57 +09:00