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 (
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|---|---|---|
| .. | ||
| core.c | ||
| Kconfig | ||
| Makefile | ||
| nf_conntrack_amanda.c | ||
| nf_conntrack_core.c | ||
| nf_conntrack_ecache.c | ||
| nf_conntrack_expect.c | ||
| nf_conntrack_extend.c | ||
| nf_conntrack_ftp.c | ||
| nf_conntrack_h323_asn1.c | ||
| nf_conntrack_h323_main.c | ||
| nf_conntrack_h323_types.c | ||
| nf_conntrack_helper.c | ||
| nf_conntrack_irc.c | ||
| nf_conntrack_l3proto_generic.c | ||
| nf_conntrack_netbios_ns.c | ||
| nf_conntrack_netlink.c | ||
| nf_conntrack_pptp.c | ||
| nf_conntrack_proto_dccp.c | ||
| nf_conntrack_proto_generic.c | ||
| nf_conntrack_proto_gre.c | ||
| nf_conntrack_proto_sctp.c | ||
| nf_conntrack_proto_tcp.c | ||
| nf_conntrack_proto_udp.c | ||
| nf_conntrack_proto_udplite.c | ||
| nf_conntrack_proto.c | ||
| nf_conntrack_sane.c | ||
| nf_conntrack_sip.c | ||
| nf_conntrack_standalone.c | ||
| nf_conntrack_tftp.c | ||
| nf_internals.h | ||
| nf_log.c | ||
| nf_queue.c | ||
| nf_sockopt.c | ||
| nfnetlink_log.c | ||
| nfnetlink_queue.c | ||
| nfnetlink.c | ||
| x_tables.c | ||
| xt_CLASSIFY.c | ||
| xt_comment.c | ||
| xt_connbytes.c | ||
| xt_connlimit.c | ||
| xt_connmark.c | ||
| xt_CONNMARK.c | ||
| xt_CONNSECMARK.c | ||
| xt_conntrack.c | ||
| xt_dccp.c | ||
| xt_dscp.c | ||
| xt_DSCP.c | ||
| xt_esp.c | ||
| xt_hashlimit.c | ||
| xt_helper.c | ||
| xt_iprange.c | ||
| xt_length.c | ||
| xt_limit.c | ||
| xt_mac.c | ||
| xt_mark.c | ||
| xt_MARK.c | ||
| xt_multiport.c | ||
| xt_NFLOG.c | ||
| xt_NFQUEUE.c | ||
| xt_NOTRACK.c | ||
| xt_owner.c | ||
| xt_physdev.c | ||
| xt_pkttype.c | ||
| xt_policy.c | ||
| xt_quota.c | ||
| xt_rateest.c | ||
| xt_RATEEST.c | ||
| xt_realm.c | ||
| xt_sctp.c | ||
| xt_SECMARK.c | ||
| xt_state.c | ||
| xt_statistic.c | ||
| xt_string.c | ||
| xt_tcpmss.c | ||
| xt_TCPMSS.c | ||
| xt_TCPOPTSTRIP.c | ||
| xt_tcpudp.c | ||
| xt_time.c | ||
| xt_TRACE.c | ||
| xt_u32.c | ||