From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Vasily Averin <vvs@virtuozzo.com>,
"David S . Miller" <davem@davemloft.net>,
Sasha Levin <sashal@kernel.org>,
netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 5.10 07/17] ipv6: allocate enough headroom in ip6_finish_output2()
Date: Thu, 22 Jul 2021 23:57:38 -0400 [thread overview]
Message-ID: <20210723035748.531594-7-sashal@kernel.org> (raw)
In-Reply-To: <20210723035748.531594-1-sashal@kernel.org>
From: Vasily Averin <vvs@virtuozzo.com>
[ Upstream commit 5796015fa968a3349027a27dcd04c71d95c53ba5 ]
When TEE target mirrors traffic to another interface, sk_buff may
not have enough headroom to be processed correctly.
ip_finish_output2() detect this situation for ipv4 and allocates
new skb with enogh headroom. However ipv6 lacks this logic in
ip_finish_output2 and it leads to skb_under_panic:
skbuff: skb_under_panic: text:ffffffffc0866ad4 len:96 put:24
head:ffff97be85e31800 data:ffff97be85e317f8 tail:0x58 end:0xc0 dev:gre0
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:110!
invalid opcode: 0000 [#1] SMP PTI
CPU: 2 PID: 393 Comm: kworker/2:2 Tainted: G OE 5.13.0 #13
Hardware name: Virtuozzo KVM, BIOS 1.11.0-2.vz7.4 04/01/2014
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:skb_panic+0x48/0x4a
Call Trace:
skb_push.cold.111+0x10/0x10
ipgre_header+0x24/0xf0 [ip_gre]
neigh_connected_output+0xae/0xf0
ip6_finish_output2+0x1a8/0x5a0
ip6_output+0x5c/0x110
nf_dup_ipv6+0x158/0x1000 [nf_dup_ipv6]
tee_tg6+0x2e/0x40 [xt_TEE]
ip6t_do_table+0x294/0x470 [ip6_tables]
nf_hook_slow+0x44/0xc0
nf_hook.constprop.34+0x72/0xe0
ndisc_send_skb+0x20d/0x2e0
ndisc_send_ns+0xd1/0x210
addrconf_dad_work+0x3c8/0x540
process_one_work+0x1d1/0x370
worker_thread+0x30/0x390
kthread+0x116/0x130
ret_from_fork+0x22/0x30
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv6/ip6_output.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 077d43af8226..f16f88ab608c 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -60,10 +60,38 @@ static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff *
{
struct dst_entry *dst = skb_dst(skb);
struct net_device *dev = dst->dev;
+ unsigned int hh_len = LL_RESERVED_SPACE(dev);
+ int delta = hh_len - skb_headroom(skb);
const struct in6_addr *nexthop;
struct neighbour *neigh;
int ret;
+ /* Be paranoid, rather than too clever. */
+ if (unlikely(delta > 0) && dev->header_ops) {
+ /* pskb_expand_head() might crash, if skb is shared */
+ if (skb_shared(skb)) {
+ struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
+
+ if (likely(nskb)) {
+ if (skb->sk)
+ skb_set_owner_w(skb, skb->sk);
+ consume_skb(skb);
+ } else {
+ kfree_skb(skb);
+ }
+ skb = nskb;
+ }
+ if (skb &&
+ pskb_expand_head(skb, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
+ kfree_skb(skb);
+ skb = NULL;
+ }
+ if (!skb) {
+ IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS);
+ return -ENOMEM;
+ }
+ }
+
if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
--
2.30.2
next prev parent reply other threads:[~2021-07-23 3:58 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-23 3:57 [PATCH AUTOSEL 5.10 01/17] net/802/mrp: fix memleak in mrp_request_join() Sasha Levin
2021-07-23 3:57 ` [PATCH AUTOSEL 5.10 02/17] net/802/garp: fix memleak in garp_request_join() Sasha Levin
2021-07-23 3:57 ` [PATCH AUTOSEL 5.10 03/17] net: annotate data race around sk_ll_usec Sasha Levin
2021-07-23 3:57 ` [PATCH AUTOSEL 5.10 04/17] sctp: move 198 addresses from unusable to private scope Sasha Levin
2021-07-23 3:57 ` [PATCH AUTOSEL 5.10 05/17] rcu-tasks: Don't delete holdouts within trc_inspect_reader() Sasha Levin
2021-07-23 3:57 ` [PATCH AUTOSEL 5.10 06/17] rcu-tasks: Don't delete holdouts within trc_wait_for_one_reader() Sasha Levin
2021-07-23 3:57 ` Sasha Levin [this message]
2021-07-23 3:57 ` [PATCH AUTOSEL 5.10 08/17] drm/ttm: add a check against null pointer dereference Sasha Levin
2021-07-23 3:57 ` [PATCH AUTOSEL 5.10 09/17] hfs: add missing clean-up in hfs_fill_super Sasha Levin
2021-07-23 3:57 ` [PATCH AUTOSEL 5.10 10/17] hfs: fix high memory mapping in hfs_bnode_read Sasha Levin
2021-07-23 3:57 ` [PATCH AUTOSEL 5.10 11/17] hfs: add lock nesting notation to hfs_find_init Sasha Levin
2021-07-23 3:57 ` [PATCH AUTOSEL 5.10 12/17] firmware: arm_scmi: Fix possible scmi_linux_errmap buffer overflow Sasha Levin
2021-07-23 3:57 ` [PATCH AUTOSEL 5.10 13/17] firmware: arm_scmi: Fix range check for the maximum number of pending messages Sasha Levin
2021-07-23 3:57 ` [PATCH AUTOSEL 5.10 14/17] cifs: fix the out of range assignment to bit fields in parse_server_interfaces Sasha Levin
2021-07-23 3:57 ` [PATCH AUTOSEL 5.10 15/17] iomap: remove the length variable in iomap_seek_data Sasha Levin
2021-07-23 3:57 ` [PATCH AUTOSEL 5.10 16/17] iomap: remove the length variable in iomap_seek_hole Sasha Levin
2021-07-23 3:57 ` [PATCH AUTOSEL 5.10 17/17] ARM: dts: versatile: Fix up interrupt controller node names Sasha Levin
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