From: Florian Fainelli <f.fainelli@gmail.com>
To: netdev@vger.kernel.org
Cc: davem@davemloft.net, gregkh@linuxfoundation.org,
stable@vger.kernel.org, edumazet@google.com,
sthemmin@microsoft.com, Taehee Yoo <ap420073@gmail.com>
Subject: [PATCH stable 4.9 29/29] ip: frags: fix crash in ip_do_fragment()
Date: Tue, 9 Oct 2018 15:49:24 -0700 [thread overview]
Message-ID: <20181009224924.30151-30-f.fainelli@gmail.com> (raw)
In-Reply-To: <20181009224924.30151-1-f.fainelli@gmail.com>
From: Taehee Yoo <ap420073@gmail.com>
commit 5d407b071dc369c26a38398326ee2be53651cfe4 upstream
A kernel crash occurrs when defragmented packet is fragmented
in ip_do_fragment().
In defragment routine, skb_orphan() is called and
skb->ip_defrag_offset is set. but skb->sk and
skb->ip_defrag_offset are same union member. so that
frag->sk is not NULL.
Hence crash occurrs in skb->sk check routine in ip_do_fragment() when
defragmented packet is fragmented.
test commands:
%iptables -t nat -I POSTROUTING -j MASQUERADE
%hping3 192.168.4.2 -s 1000 -p 2000 -d 60000
splat looks like:
[ 261.069429] kernel BUG at net/ipv4/ip_output.c:636!
[ 261.075753] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 261.083854] CPU: 1 PID: 1349 Comm: hping3 Not tainted 4.19.0-rc2+ #3
[ 261.100977] RIP: 0010:ip_do_fragment+0x1613/0x2600
[ 261.106945] Code: e8 e2 38 e3 fe 4c 8b 44 24 18 48 8b 74 24 08 e9 92 f6 ff ff 80 3c 02 00 0f 85 da 07 00 00 48 8b b5 d0 00 00 00 e9 25 f6 ff ff <0f> 0b 0f 0b 44 8b 54 24 58 4c 8b 4c 24 18 4c 8b 5c 24 60 4c 8b 6c
[ 261.127015] RSP: 0018:ffff8801031cf2c0 EFLAGS: 00010202
[ 261.134156] RAX: 1ffff1002297537b RBX: ffffed0020639e6e RCX: 0000000000000004
[ 261.142156] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880114ba9bd8
[ 261.150157] RBP: ffff880114ba8a40 R08: ffffed0022975395 R09: ffffed0022975395
[ 261.158157] R10: 0000000000000001 R11: ffffed0022975394 R12: ffff880114ba9ca4
[ 261.166159] R13: 0000000000000010 R14: ffff880114ba9bc0 R15: dffffc0000000000
[ 261.174169] FS: 00007fbae2199700(0000) GS:ffff88011b400000(0000) knlGS:0000000000000000
[ 261.183012] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 261.189013] CR2: 00005579244fe000 CR3: 0000000119bf4000 CR4: 00000000001006e0
[ 261.198158] Call Trace:
[ 261.199018] ? dst_output+0x180/0x180
[ 261.205011] ? save_trace+0x300/0x300
[ 261.209018] ? ip_copy_metadata+0xb00/0xb00
[ 261.213034] ? sched_clock_local+0xd4/0x140
[ 261.218158] ? kill_l4proto+0x120/0x120 [nf_conntrack]
[ 261.223014] ? rt_cpu_seq_stop+0x10/0x10
[ 261.227014] ? find_held_lock+0x39/0x1c0
[ 261.233008] ip_finish_output+0x51d/0xb50
[ 261.237006] ? ip_fragment.constprop.56+0x220/0x220
[ 261.243011] ? nf_ct_l4proto_register_one+0x5b0/0x5b0 [nf_conntrack]
[ 261.250152] ? rcu_is_watching+0x77/0x120
[ 261.255010] ? nf_nat_ipv4_out+0x1e/0x2b0 [nf_nat_ipv4]
[ 261.261033] ? nf_hook_slow+0xb1/0x160
[ 261.265007] ip_output+0x1c7/0x710
[ 261.269005] ? ip_mc_output+0x13f0/0x13f0
[ 261.273002] ? __local_bh_enable_ip+0xe9/0x1b0
[ 261.278152] ? ip_fragment.constprop.56+0x220/0x220
[ 261.282996] ? nf_hook_slow+0xb1/0x160
[ 261.287007] raw_sendmsg+0x21f9/0x4420
[ 261.291008] ? dst_output+0x180/0x180
[ 261.297003] ? sched_clock_cpu+0x126/0x170
[ 261.301003] ? find_held_lock+0x39/0x1c0
[ 261.306155] ? stop_critical_timings+0x420/0x420
[ 261.311004] ? check_flags.part.36+0x450/0x450
[ 261.315005] ? _raw_spin_unlock_irq+0x29/0x40
[ 261.320995] ? _raw_spin_unlock_irq+0x29/0x40
[ 261.326142] ? cyc2ns_read_end+0x10/0x10
[ 261.330139] ? raw_bind+0x280/0x280
[ 261.334138] ? sched_clock_cpu+0x126/0x170
[ 261.338995] ? check_flags.part.36+0x450/0x450
[ 261.342991] ? __lock_acquire+0x4500/0x4500
[ 261.348994] ? inet_sendmsg+0x11c/0x500
[ 261.352989] ? dst_output+0x180/0x180
[ 261.357012] inet_sendmsg+0x11c/0x500
[ ... ]
v2:
- clear skb->sk at reassembly routine.(Eric Dumarzet)
Fixes: fa0f527358bd ("ip: use rb trees for IP frag queue.")
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv4/ip_fragment.c | 1 +
net/ipv6/netfilter/nf_conntrack_reasm.c | 1 +
2 files changed, 2 insertions(+)
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 8f899c13a392..cc8c6ac84d08 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -597,6 +597,7 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
nextp = &fp->next;
fp->prev = NULL;
memset(&fp->rbnode, 0, sizeof(fp->rbnode));
+ fp->sk = NULL;
head->data_len += fp->len;
head->len += fp->len;
if (head->ip_summed != fp->ip_summed)
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 907c2d5753dd..b9147558a8f2 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -452,6 +452,7 @@ nf_ct_frag6_reasm(struct frag_queue *fq, struct sk_buff *prev, struct net_devic
else if (head->ip_summed == CHECKSUM_COMPLETE)
head->csum = csum_add(head->csum, fp->csum);
head->truesize += fp->truesize;
+ fp->sk = NULL;
}
sub_frag_mem_limit(fq->q.net, head->truesize);
--
2.17.1
next prev parent reply other threads:[~2018-10-10 6:09 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-09 22:48 [PATCH stable 4.9 00/29] backport of IP fragmentation fixes Florian Fainelli
2018-10-09 22:48 ` [PATCH stable 4.9 01/29] inet: frags: change inet_frags_init_net() return value Florian Fainelli
2018-10-09 22:48 ` [PATCH stable 4.9 02/29] inet: frags: add a pointer to struct netns_frags Florian Fainelli
2018-10-09 22:48 ` [PATCH stable 4.9 03/29] inet: frags: refactor ipfrag_init() Florian Fainelli
2018-10-09 22:48 ` [PATCH stable 4.9 04/29] inet: frags: refactor ipv6_frag_init() Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 05/29] inet: frags: refactor lowpan_net_frag_init() Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 06/29] ipv6: export ip6 fragments sysctl to unprivileged users Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 07/29] rhashtable: add schedule points Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 08/29] inet: frags: use rhashtables for reassembly units Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 09/29] inet: frags: remove some helpers Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 10/29] inet: frags: get rif of inet_frag_evicting() Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 11/29] inet: frags: remove inet_frag_maybe_warn_overflow() Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 12/29] inet: frags: break the 2GB limit for frags storage Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 13/29] inet: frags: do not clone skb in ip_expire() Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 14/29] ipv6: frags: rewrite ip6_expire_frag_queue() Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 15/29] rhashtable: reorganize struct rhashtable layout Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 16/29] inet: frags: reorganize struct netns_frags Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 17/29] inet: frags: get rid of ipfrag_skb_cb/FRAG_CB Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 18/29] inet: frags: fix ip6frag_low_thresh boundary Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 19/29] ip: discard IPv4 datagrams with overlapping segments Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 20/29] net: speed up skb_rbtree_purge() Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 21/29] net: modify skb_rbtree_purge to return the truesize of all purged skbs Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 22/29] ipv6: defrag: drop non-last frags smaller than min mtu Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 23/29] net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 24/29] net: add rb_to_skb() and other rb tree helpers Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 25/29] net: sk_buff rbnode reorg Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 26/29] ipv4: frags: precedence bug in ip_expire() Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 27/29] ip: add helpers to process in-order fragments faster Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 28/29] ip: process in-order fragments efficiently Florian Fainelli
2018-10-09 22:49 ` Florian Fainelli [this message]
2018-10-10 0:46 ` [PATCH stable 4.9 00/29] backport of IP fragmentation fixes Eric Dumazet
2018-10-10 4:15 ` Florian Fainelli
2018-10-10 23:18 ` Stephen Hemminger
2018-10-10 23:23 ` Florian Fainelli
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