| Message ID | 1273649526.2621.3.camel@edumazet-laptop |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
Eric Dumazet wrote: > Le mardi 11 mai 2010 à 20:25 -0700, Stephen Hemminger a écrit : >> This is a regression that is showing up now in net-next, not sure what >> changed recently in bridge netfilter that could be causing it? >> >> [ 4593.956206] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 >> [ 4593.956219] IP: [<ffffffffa03357a4>] br_nf_forward_finish+0x154/0x170 [bridge] >> [ 4593.956232] PGD 195ece067 PUD 1ba005067 PMD 0 >> [ 4593.956241] Oops: 0000 [#1] SMP >> [ 4593.956248] last sysfs file: /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:08/ATK0110:00/hwmon/hwmon0/temp2_label >> [ 4593.956253] CPU 3 >> [ 4593.956256] Modules linked in: netconsole configfs hid_belkin tun ntfs vfat msdos fat autofs4 binfmt_misc ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp llc kvm_intel kvm radeon ttm drm_kms_helper drm i2c_algo_bit snd_hda_codec_analog ipv6 snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_dummy snd_seq_oss snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device psmouse asus_atk0110 snd serio_raw soundcore snd_page_alloc usbhid mvsas libsas scsi_transport_sas floppy sky2 e1000e [last unloaded: netconsole] >> [ 4593.956375] >> [ 4593.956380] Pid: 29512, comm: kvm Not tainted 2.6.34-rc7-net #195 P6T DELUXE/System Product Name >> [ 4593.956384] RIP: 0010:[<ffffffffa03357a4>] [<ffffffffa03357a4>] br_nf_forward_finish+0x154/0x170 [bridge] >> [ 4593.956395] RSP: 0018:ffff880001e63b78 EFLAGS: 00010246 >> [ 4593.956399] RAX: 0000000000000608 RBX: ffff880057181700 RCX: ffff8801b813d000 >> [ 4593.956402] RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff880057181700 >> [ 4593.956406] RBP: ffff880001e63ba8 R08: ffff8801b9d97000 R09: ffffffffa0335650 >> [ 4593.956410] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801b813d000 >> [ 4593.956413] R13: ffffffff81ab3940 R14: ffff880057181700 R15: 0000000000000002 >> [ 4593.956418] FS: 00007fc40d380710(0000) GS:ffff880001e60000(0000) knlGS:0000000000000000 >> [ 4593.956422] CS: 0010 DS: 002b ES: 002b CR0: 000000008005003b >> [ 4593.956426] CR2: 0000000000000018 CR3: 00000001ba1d7000 CR4: 00000000000026e0 >> [ 4593.956429] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >> [ 4593.956433] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 >> [ 4593.956437] Process kvm (pid: 29512, threadinfo ffff8801ba566000, task ffff8801b8003870) >> [ 4593.956441] Stack: >> [ 4593.956443] 0000000100000020 ffff880001e63ba0 ffff880001e63ba0 ffff880057181700 >> [ 4593.956451] <0> ffffffffa0335650 ffffffff81ab3940 ffff880001e63bd8 ffffffffa03350e6 >> [ 4593.956462] <0> ffff880001e63c40 000000000000024d ffff880057181700 0000000080000000 >> [ 4593.956474] Call Trace: >> [ 4593.956478] <IRQ> >> [ 4593.956488] [<ffffffffa0335650>] ? br_nf_forward_finish+0x0/0x170 [bridge] >> [ 4593.956496] [<ffffffffa03350e6>] NF_HOOK_THRESH+0x56/0x60 [bridge] >> [ 4593.956504] [<ffffffffa0335282>] br_nf_forward_arp+0x112/0x120 [bridge] >> [ 4593.956511] [<ffffffff813f7184>] nf_iterate+0x64/0xa0 >> [ 4593.956519] [<ffffffffa032f920>] ? br_forward_finish+0x0/0x60 [bridge] >> [ 4593.956524] [<ffffffff813f722c>] nf_hook_slow+0x6c/0x100 >> [ 4593.956531] [<ffffffffa032f920>] ? br_forward_finish+0x0/0x60 [bridge] >> [ 4593.956538] [<ffffffffa032f800>] ? __br_forward+0x0/0xc0 [bridge] >> [ 4593.956545] [<ffffffffa032f86d>] __br_forward+0x6d/0xc0 [bridge] >> [ 4593.956550] [<ffffffff813c5d8e>] ? skb_clone+0x3e/0x70 > > Not sure, but br_nf_forward_ip() has following check : > > if (!skb->nf_bridge) > return NF_ACCEPT; > > while br_nf_forward_arp() missed this check ... > > So we can dereference null pointer later That looks correct to me, offset 0x18 would be nf_bridge_info->mask. Bart, please review, thanks. > > diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c > index 93f80fe..cd2e5f5 100644 > --- a/net/bridge/br_netfilter.c > +++ b/net/bridge/br_netfilter.c > @@ -723,6 +723,9 @@ static unsigned int br_nf_forward_arp(unsigned int hook, struct sk_buff *skb, > return NF_ACCEPT; > #endif > > + if (!skb->nf_bridge) > + return NF_ACCEPT; > + > if (skb->protocol != htons(ETH_P_ARP)) { > if (!IS_VLAN_ARP(skb)) > return NF_ACCEPT; > > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index 93f80fe..cd2e5f5 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -723,6 +723,9 @@ static unsigned int br_nf_forward_arp(unsigned int hook, struct sk_buff *skb, return NF_ACCEPT; #endif + if (!skb->nf_bridge) + return NF_ACCEPT; + if (skb->protocol != htons(ETH_P_ARP)) { if (!IS_VLAN_ARP(skb)) return NF_ACCEPT;