Commit 0317268f authored by Antoine Tenart's avatar Antoine Tenart Committed by Guo Mengqi
Browse files

tunnels: fix out of bounds access when building IPv6 PMTU error 

stable inclusion
from stable-v5.10.210
commit e77bf828f1ca1c47fcff58bdc26b60a9d3dfbe1d
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9DNVF

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e77bf828f1ca1c47fcff58bdc26b60a9d3dfbe1d



--------------------------------

[ Upstream commit d75abeec401f8c86b470e7028a13fcdc87e5dd06 ]

If the ICMPv6 error is built from a non-linear skb we get the following
splat,

  BUG: KASAN: slab-out-of-bounds in do_csum+0x220/0x240
  Read of size 4 at addr ffff88811d402c80 by task netperf/820
  CPU: 0 PID: 820 Comm: netperf Not tainted 6.8.0-rc1+ #543
  ...
   kasan_report+0xd8/0x110
   do_csum+0x220/0x240
   csum_partial+0xc/0x20
   skb_tunnel_check_pmtu+0xeb9/0x3280
   vxlan_xmit_one+0x14c2/0x4080
   vxlan_xmit+0xf61/0x5c00
   dev_hard_start_xmit+0xfb/0x510
   __dev_queue_xmit+0x7cd/0x32a0
   br_dev_queue_push_xmit+0x39d/0x6a0

Use skb_checksum instead of csum_partial who cannot deal with non-linear
SKBs.

Fixes: 4cb47a86 ("tunnels: PMTU discovery support for directly bridged IP packets")
Signed-off-by: default avatarAntoine Tenart <atenart@kernel.org>
Reviewed-by: default avatarJiri Pirko <jiri@nvidia.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarWang Hai <wanghai38@huawei.com>
parent 1df0d53c

net/ipv4/ip_tunnel_core.c

+1 −1
Original line number Diff line number Diff line
@@ -332,7 +332,7 @@ static int iptunnel_pmtud_build_icmpv6(struct sk_buff *skb, int mtu) 
	};

	skb_reset_network_header(skb);



	csum = csum_partial(icmp6h, len, 0);

	csum = skb_checksum(skb, skb_transport_offset(skb), len, 0);

	icmp6h->icmp6_cksum = csum_ipv6_magic(&nip6h->saddr, &nip6h->daddr, len,

					      IPPROTO_ICMPV6, csum);