From: linmiaohe <linmiaohe@huawei.com>
To: <davem@davemloft.net>, <kuznet@ms2.inr.ac.ru>,
<yoshfuji@linux-ipv6.org>, <netdev@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Cc: Mingfangsen <mingfangsen@huawei.com>
Subject: [PATCH net] net: sit: fix UBSAN Undefined behaviour in check_6rd
Date: Mon, 11 Mar 2019 16:29:32 +0800 [thread overview]
Message-ID: <694fb074-53a3-af60-6561-57c022445a48@huawei.com> (raw)
From: Miaohe Lin <linmiaohe@huawei.com>
In func check_6rd,tunnel->ip6rd.relay_prefixlen may equal to
32,so UBSAN complain about it.
UBSAN: Undefined behaviour in net/ipv6/sit.c:781:47
shift exponent 32 is too large for 32-bit type 'unsigned int'
CPU: 6 PID: 20036 Comm: syz-executor.0 Not tainted 4.19.27 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1
04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xca/0x13e lib/dump_stack.c:113
ubsan_epilogue+0xe/0x81 lib/ubsan.c:159
__ubsan_handle_shift_out_of_bounds+0x293/0x2e8 lib/ubsan.c:425
check_6rd.constprop.9+0x433/0x4e0 net/ipv6/sit.c:781
try_6rd net/ipv6/sit.c:806 [inline]
ipip6_tunnel_xmit net/ipv6/sit.c:866 [inline]
sit_tunnel_xmit+0x141c/0x2720 net/ipv6/sit.c:1033
__netdev_start_xmit include/linux/netdevice.h:4300 [inline]
netdev_start_xmit include/linux/netdevice.h:4309 [inline]
xmit_one net/core/dev.c:3243 [inline]
dev_hard_start_xmit+0x17c/0x780 net/core/dev.c:3259
__dev_queue_xmit+0x1656/0x2500 net/core/dev.c:3829
neigh_output include/net/neighbour.h:501 [inline]
ip6_finish_output2+0xa36/0x2290 net/ipv6/ip6_output.c:120
ip6_finish_output+0x3e7/0xa20 net/ipv6/ip6_output.c:154
NF_HOOK_COND include/linux/netfilter.h:278 [inline]
ip6_output+0x1e2/0x720 net/ipv6/ip6_output.c:171
dst_output include/net/dst.h:444 [inline]
ip6_local_out+0x99/0x170 net/ipv6/output_core.c:176
ip6_send_skb+0x9d/0x2f0 net/ipv6/ip6_output.c:1697
ip6_push_pending_frames+0xc0/0x100 net/ipv6/ip6_output.c:1717
rawv6_push_pending_frames net/ipv6/raw.c:616 [inline]
rawv6_sendmsg+0x2435/0x3530 net/ipv6/raw.c:946
inet_sendmsg+0xf8/0x5c0 net/ipv4/af_inet.c:798
sock_sendmsg_nosec net/socket.c:621 [inline]
sock_sendmsg+0xc8/0x110 net/socket.c:631
___sys_sendmsg+0x6cf/0x890 net/socket.c:2114
__sys_sendmsg+0xf0/0x1b0 net/socket.c:2152
do_syscall_64+0xc8/0x580 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Signed-off-by: linmiaohe <linmiaohe@huawei.com>
---
net/ipv6/sit.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 09e440e8dfae..07e21a82ce4c 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -778,8 +778,9 @@ static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
pbw0 = tunnel->ip6rd.prefixlen >> 5;
pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
- d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
- tunnel->ip6rd.relay_prefixlen;
+ d = tunnel->ip6rd.relay_prefixlen < 32 ?
+ (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
+ tunnel->ip6rd.relay_prefixlen : 0;
pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
if (pbi1 > 0)
--
2.16.2
next reply other threads:[~2019-03-11 8:29 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-11 8:29 linmiaohe [this message]
2019-03-11 17:29 ` [PATCH net] net: sit: fix UBSAN Undefined behaviour in check_6rd David Miller
2019-03-11 17:30 ` David Miller
2019-03-12 6:01 ` linmiaohe
2019-03-12 6:08 ` linmiaohe
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