From 9d89081d698132b5f964aea88112f76492563ee9 Mon Sep 17 00:00:00 2001 From: Tomas Winkler Date: Mon, 3 Jan 2011 11:26:08 -0800 Subject: [PATCH] bridge: fix br_multicast_ipv6_rcv for paged skbs use pskb_may_pull to access ipv6 header correctly for paged skbs It was omitted in the bridge code leading to crash in blind __skb_pull since the skb is cloned undonditionally we also simplify the the exit path this fixes bug https://bugzilla.kernel.org/show_bug.cgi?id=25202 Dec 15 14:36:40 User-PC hostapd: wlan0: STA 00:15:00:60:5d:34 IEEE 802.11: authenticated Dec 15 14:36:40 User-PC hostapd: wlan0: STA 00:15:00:60:5d:34 IEEE 802.11: associated (aid 2) Dec 15 14:36:40 User-PC hostapd: wlan0: STA 00:15:00:60:5d:34 RADIUS: starting accounting session 4D0608A3-00000005 Dec 15 14:36:41 User-PC kernel: [175576.120287] ------------[ cut here ]------------ Dec 15 14:36:41 User-PC kernel: [175576.120452] kernel BUG at include/linux/skbuff.h:1178! Dec 15 14:36:41 User-PC kernel: [175576.120609] invalid opcode: 0000 [#1] SMP Dec 15 14:36:41 User-PC kernel: [175576.120749] last sysfs file: /sys/devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/uevent Dec 15 14:36:41 User-PC kernel: [175576.121035] Modules linked in: approvals binfmt_misc bridge stp llc parport_pc ppdev arc4 iwlagn snd_hda_codec_realtek iwlcore i915 snd_hda_intel mac80211 joydev snd_hda_codec snd_hwdep snd_pcm snd_seq_midi drm_kms_helper snd_rawmidi drm snd_seq_midi_event snd_seq snd_timer snd_seq_device cfg80211 eeepc_wmi usbhid psmouse intel_agp i2c_algo_bit intel_gtt uvcvideo agpgart videodev sparse_keymap snd shpchp v4l1_compat lp hid video serio_raw soundcore output snd_page_alloc ahci libahci atl1c Dec 15 14:36:41 User-PC kernel: [175576.122712] Dec 15 14:36:41 User-PC kernel: [175576.122769] Pid: 0, comm: kworker/0:0 Tainted: G W 2.6.37-rc5-wl+ #3 1015PE/1016P Dec 15 14:36:41 User-PC kernel: [175576.123012] EIP: 0060:[] EFLAGS: 00010283 CPU: 1 Dec 15 14:36:41 User-PC kernel: [175576.123193] EIP is at br_multicast_rcv+0xc95/0xe1c [bridge] Dec 15 14:36:41 User-PC kernel: [175576.123362] EAX: 0000001c EBX: f5626318 ECX: 00000000 EDX: 00000000 Dec 15 14:36:41 User-PC kernel: [175576.123550] ESI: ec512262 EDI: f5626180 EBP: f60b5ca0 ESP: f60b5bd8 Dec 15 14:36:41 User-PC kernel: [175576.123737] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 Dec 15 14:36:41 User-PC kernel: [175576.123902] Process kworker/0:0 (pid: 0, ti=f60b4000 task=f60a8000 task.ti=f60b0000) Dec 15 14:36:41 User-PC kernel: [175576.124137] Stack: Dec 15 14:36:41 User-PC kernel: [175576.124181] ec556500 f6d06800 f60b5be8 c01087d8 ec512262 00000030 00000024 f5626180 Dec 15 14:36:41 User-PC kernel: [175576.124181] f572c200 ef463440 f5626300 3affffff f6d06dd0 e60766a4 000000c4 f6d06860 Dec 15 14:36:41 User-PC kernel: [175576.124181] ffffffff ec55652c 00000001 f6d06844 f60b5c64 c0138264 c016e451 c013e47d Dec 15 14:36:41 User-PC kernel: [175576.124181] Call Trace: Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? sched_clock+0x8/0x10 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? enqueue_entity+0x174/0x440 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? sched_clock_cpu+0x131/0x190 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? select_task_rq_fair+0x2ad/0x730 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? nf_iterate+0x71/0x90 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? br_handle_frame_finish+0x184/0x220 [bridge] Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? br_handle_frame_finish+0x0/0x220 [bridge] Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? br_handle_frame+0x189/0x230 [bridge] Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? br_handle_frame_finish+0x0/0x220 [bridge] Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? br_handle_frame+0x0/0x230 [bridge] Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? __netif_receive_skb+0x1b6/0x5b0 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? skb_copy_bits+0x110/0x210 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? netif_receive_skb+0x6f/0x80 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? ieee80211_deliver_skb+0x8c/0x1a0 [mac80211] Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? ieee80211_rx_handlers+0xeb6/0x1aa0 [mac80211] Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? __netif_receive_skb+0x380/0x5b0 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? sched_clock_local+0xb2/0x190 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? default_spin_lock_flags+0x8/0x10 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? _raw_spin_lock_irqsave+0x2f/0x50 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? ieee80211_prepare_and_rx_handle+0x201/0xa90 [mac80211] Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? ieee80211_rx+0x2a4/0x830 [mac80211] Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? iwl_update_stats+0xa6/0x2a0 [iwlcore] Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? iwlagn_rx_reply_rx+0x292/0x3b0 [iwlagn] Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? _raw_spin_lock_irqsave+0x2f/0x50 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? iwl_rx_handle+0xe7/0x350 [iwlagn] Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? iwl_irq_tasklet+0xf7/0x5c0 [iwlagn] Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? __rcu_process_callbacks+0x201/0x2d0 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? tasklet_action+0xc5/0x100 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? __do_softirq+0x97/0x1d0 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? nmi_stack_correct+0x2f/0x34 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? __do_softirq+0x0/0x1d0 Dec 15 14:36:41 User-PC kernel: [175576.124181] Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? irq_exit+0x65/0x70 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? do_IRQ+0x52/0xc0 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? common_interrupt+0x30/0x38 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? intel_idle+0xc2/0x160 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? cpuidle_idle_call+0x6b/0x100 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? cpu_idle+0x8a/0xf0 Dec 15 14:36:41 User-PC kernel: [175576.124181] [] ? start_secondary+0x1e8/0x1ee Cc: David Miller Cc: Johannes Berg Cc: Stephen Hemminger Signed-off-by: Tomas Winkler Signed-off-by: David S. Miller --- net/bridge/br_multicast.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index f19e347f56f6..543b3262d002 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1430,7 +1430,7 @@ static int br_multicast_ipv6_rcv(struct net_bridge *br, struct net_bridge_port *port, struct sk_buff *skb) { - struct sk_buff *skb2 = skb; + struct sk_buff *skb2; struct ipv6hdr *ip6h; struct icmp6hdr *icmp6h; u8 nexthdr; @@ -1469,15 +1469,15 @@ static int br_multicast_ipv6_rcv(struct net_bridge *br, if (!skb2) return -ENOMEM; + err = -EINVAL; + if (!pskb_may_pull(skb2, offset + sizeof(struct icmp6hdr))) + goto out; + len -= offset - skb_network_offset(skb2); __skb_pull(skb2, offset); skb_reset_transport_header(skb2); - err = -EINVAL; - if (!pskb_may_pull(skb2, sizeof(*icmp6h))) - goto out; - icmp6h = icmp6_hdr(skb2); switch (icmp6h->icmp6_type) { @@ -1516,7 +1516,12 @@ static int br_multicast_ipv6_rcv(struct net_bridge *br, switch (icmp6h->icmp6_type) { case ICMPV6_MGM_REPORT: { - struct mld_msg *mld = (struct mld_msg *)icmp6h; + struct mld_msg *mld; + if (!pskb_may_pull(skb2, sizeof(*mld))) { + err = -EINVAL; + goto out; + } + mld = (struct mld_msg *)skb_transport_header(skb2); BR_INPUT_SKB_CB(skb2)->mrouters_only = 1; err = br_ip6_multicast_add_group(br, port, &mld->mld_mca); break; @@ -1529,15 +1534,18 @@ static int br_multicast_ipv6_rcv(struct net_bridge *br, break; case ICMPV6_MGM_REDUCTION: { - struct mld_msg *mld = (struct mld_msg *)icmp6h; + struct mld_msg *mld; + if (!pskb_may_pull(skb2, sizeof(*mld))) { + err = -EINVAL; + goto out; + } + mld = (struct mld_msg *)skb_transport_header(skb2); br_ip6_multicast_leave_group(br, port, &mld->mld_mca); } } out: - __skb_push(skb2, offset); - if (skb2 != skb) - kfree_skb(skb2); + kfree_skb(skb2); return err; } #endif -- GitLab