forked from Minki/linux
9a732ed6d0
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 (
|
||
|---|---|---|
| .. | ||
| ipvs | ||
| netfilter | ||
| af_inet.c | ||
| ah4.c | ||
| arp.c | ||
| cipso_ipv4.c | ||
| datagram.c | ||
| devinet.c | ||
| esp4.c | ||
| fib_frontend.c | ||
| fib_hash.c | ||
| fib_lookup.h | ||
| fib_rules.c | ||
| fib_semantics.c | ||
| fib_trie.c | ||
| icmp.c | ||
| igmp.c | ||
| inet_connection_sock.c | ||
| inet_diag.c | ||
| inet_fragment.c | ||
| inet_hashtables.c | ||
| inet_lro.c | ||
| inet_timewait_sock.c | ||
| inetpeer.c | ||
| ip_forward.c | ||
| ip_fragment.c | ||
| ip_gre.c | ||
| ip_input.c | ||
| ip_options.c | ||
| ip_output.c | ||
| ip_sockglue.c | ||
| ipcomp.c | ||
| ipconfig.c | ||
| ipip.c | ||
| ipmr.c | ||
| Kconfig | ||
| Makefile | ||
| netfilter.c | ||
| proc.c | ||
| protocol.c | ||
| raw.c | ||
| route.c | ||
| syncookies.c | ||
| sysctl_net_ipv4.c | ||
| tcp_bic.c | ||
| tcp_cong.c | ||
| tcp_cubic.c | ||
| tcp_diag.c | ||
| tcp_highspeed.c | ||
| tcp_htcp.c | ||
| tcp_hybla.c | ||
| tcp_illinois.c | ||
| tcp_input.c | ||
| tcp_ipv4.c | ||
| tcp_lp.c | ||
| tcp_minisocks.c | ||
| tcp_output.c | ||
| tcp_probe.c | ||
| tcp_scalable.c | ||
| tcp_timer.c | ||
| tcp_vegas.c | ||
| tcp_vegas.h | ||
| tcp_veno.c | ||
| tcp_westwood.c | ||
| tcp_yeah.c | ||
| tcp.c | ||
| tunnel4.c | ||
| udp_impl.h | ||
| udp.c | ||
| udplite.c | ||
| xfrm4_input.c | ||
| xfrm4_mode_beet.c | ||
| xfrm4_mode_transport.c | ||
| xfrm4_mode_tunnel.c | ||
| xfrm4_output.c | ||
| xfrm4_policy.c | ||
| xfrm4_state.c | ||
| xfrm4_tunnel.c | ||