From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Vasily Averin <vvs@virtuozzo.com>,
"David S. Miller" <davem@davemloft.net>,
Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.10 13/24] ipv6: allocate enough headroom in ip6_finish_output2()
Date: Thu, 29 Jul 2021 15:54:33 +0200 [thread overview]
Message-ID: <20210729135137.680910375@linuxfoundation.org> (raw)
In-Reply-To: <20210729135137.267680390@linuxfoundation.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 341d0c7acc8b..781d3bc64b71 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:[~2021-07-29 13:58 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-29 13:54 [PATCH 5.10 00/24] 5.10.55-rc1 review Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 01/24] tools: Allow proper CC/CXX/... override with LLVM=1 in Makefile.include Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 02/24] [PATCH] io_uring: fix link timeout refs Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 03/24] KVM: x86: determine if an exception has an error code only when injecting it Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 04/24] af_unix: fix garbage collect vs MSG_PEEK Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 05/24] workqueue: fix UAF in pwq_unbound_release_workfn() Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 06/24] cgroup1: fix leaked context root causing sporadic NULL deref in LTP Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 07/24] net/802/mrp: fix memleak in mrp_request_join() Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 08/24] net/802/garp: fix memleak in garp_request_join() Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 09/24] net: annotate data race around sk_ll_usec Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 10/24] sctp: move 198 addresses from unusable to private scope Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 11/24] rcu-tasks: Dont delete holdouts within trc_inspect_reader() Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 12/24] rcu-tasks: Dont delete holdouts within trc_wait_for_one_reader() Greg Kroah-Hartman
2021-07-29 13:54 ` Greg Kroah-Hartman [this message]
2021-07-29 13:54 ` [PATCH 5.10 14/24] drm/ttm: add a check against null pointer dereference Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 15/24] hfs: add missing clean-up in hfs_fill_super Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 16/24] hfs: fix high memory mapping in hfs_bnode_read Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 17/24] hfs: add lock nesting notation to hfs_find_init Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 18/24] firmware: arm_scmi: Fix possible scmi_linux_errmap buffer overflow Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 19/24] firmware: arm_scmi: Fix range check for the maximum number of pending messages Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 20/24] cifs: fix the out of range assignment to bit fields in parse_server_interfaces Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 21/24] iomap: remove the length variable in iomap_seek_data Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 22/24] iomap: remove the length variable in iomap_seek_hole Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 23/24] ARM: dts: versatile: Fix up interrupt controller node names Greg Kroah-Hartman
2021-07-29 13:54 ` [PATCH 5.10 24/24] ipv6: ip6_finish_output2: set sk into newly allocated nskb Greg Kroah-Hartman
2021-07-29 18:35 ` [PATCH 5.10 00/24] 5.10.55-rc1 review Jon Hunter
2021-07-29 19:47 ` Pavel Machek
2021-07-29 22:53 ` Shuah Khan
2021-07-30 4:58 ` Greg Kroah-Hartman
2021-07-29 23:36 ` Florian Fainelli
2021-07-30 2:40 ` Shuah Khan
2021-07-30 6:23 ` Naresh Kamboju
2021-07-30 10:12 ` Sudip Mukherjee
2021-07-31 4:43 ` Guenter Roeck
2021-07-31 7:51 ` Fox Chen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210729135137.680910375@linuxfoundation.org \
--to=gregkh@linuxfoundation.org \
--cc=davem@davemloft.net \
--cc=linux-kernel@vger.kernel.org \
--cc=sashal@kernel.org \
--cc=stable@vger.kernel.org \
--cc=vvs@virtuozzo.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.