From: Michal Miroslaw Date: Sun, 4 Mar 2007 23:59:01 +0000 (-0800) Subject: [NETFILTER]: nfnetlink_log: fix NULL pointer dereference X-Git-Tag: v2.6.21-rc3~2^2~11 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a497097d35d37b47e885cf15bcaea01f279fe5e6;p=linux-2.6 [NETFILTER]: nfnetlink_log: fix NULL pointer dereference Fix the nasty NULL dereference on multiple packets per netlink message. BUG: unable to handle kernel NULL pointer dereference at virtual address 00000004 printing eip: f8a4b3bf *pde = 00000000 Oops: 0002 [#1] SMP Modules linked in: nfnetlink_log ipt_ttl ipt_REDIRECT xt_tcpudp iptable_nat nf_nat nf_conntrack_ipv4 xt_state ipt_ipp2p xt_NFLOG xt_hashlimit ip6_tables iptable_filter xt_multiport xt_mark ipt_set iptable_raw xt_MARK iptable_mangle ip_tables cls_fw cls_u32 sch_esfq sch_htb ip_set_ipmap ip_set ipt_ULOG x_tables dm_snapshot dm_mirror loop e1000 parport_pc parport e100 floppy ide_cd cdrom CPU: 0 EIP: 0060:[] Not tainted VLI EFLAGS: 00010206 (2.6.20 #5) EIP is at __nfulnl_send+0x24/0x51 [nfnetlink_log] eax: 00000000 ebx: f2b5cbc0 ecx: c03f5f54 edx: c03f4000 esi: f2b5cbc8 edi: c03f5f54 ebp: f8a4b3ec esp: c03f5f30 ds: 007b es: 007b ss: 0068 Process swapper (pid: 0, ti=c03f4000 task=c03bece0 task.ti=c03f4000) Stack: f2b5cbc0 f8a4b401 00000100 c0444080 c012af49 00000000 f6f19100 f6f19000 c1707800 c03f5f54 c03f5f54 00000123 00000021 c03e8d08 c0426380 00000009 c0126932 00000000 00000046 c03e9980 c03e6000 0047b007 c01269bd 00000000 Call Trace: [] nfulnl_timer+0x15/0x25 [nfnetlink_log] [] run_timer_softirq+0x10a/0x164 [] __do_softirq+0x60/0xba [] do_softirq+0x31/0x35 [] do_IRQ+0x62/0x74 [] common_interrupt+0x23/0x28 [] default_idle+0x0/0x3f [] default_idle+0x2d/0x3f [] cpu_idle+0xa0/0xb9 [] start_kernel+0x1a8/0x1ac [] unknown_bootoption+0x0/0x181 ======================= Code: 5e 5f 5b 5e 5f 5d c3 53 89 c3 8d 40 1c 83 7b 1c 00 74 05 e8 2c ee 6d c7 83 7b 14 00 75 04 31 c0 eb 34 83 7b 10 01 76 09 8b 43 18 <66> c7 40 04 03 00 8b 53 34 8b 43 14 b9 40 00 00 00 e8 08 9a 84 EIP: [] __nfulnl_send+0x24/0x51 [nfnetlink_log] SS:ESP 0068:c03f5f30 <0>Kernel panic - not syncing: Fatal exception in interrupt <0>Rebooting in 5 seconds.. Panic no more! Signed-off-by: Micha Mirosaw Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c index 27b844a67e..1b940512d8 100644 --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -560,6 +560,7 @@ __build_packet_message(struct nfulnl_instance *inst, } nlh->nlmsg_len = inst->skb->tail - old_tail; + inst->lastnlh = nlh; return 0; nlmsg_failure: