lkml.org 
[lkml]   [2021]   [Sep]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.19 15/33] ip_gre: add validation for csum_start
Date
From: Shreyansh Chouhan <chouhan.shreyansh630@gmail.com>

[ Upstream commit 1d011c4803c72f3907eccfc1ec63caefb852fcbf ]

Validate csum_start in gre_handle_offloads before we call _gre_xmit so
that we do not crash later when the csum_start value is used in the
lco_csum function call.

This patch deals with ipv4 code.

Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.")
Reported-by: syzbot+ff8e1b9f2f36481e2efc@syzkaller.appspotmail.com
Signed-off-by: Shreyansh Chouhan <chouhan.shreyansh630@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv4/ip_gre.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index de6f89511a21..a8a37d112820 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -449,6 +449,8 @@ static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,

static int gre_handle_offloads(struct sk_buff *skb, bool csum)
{
+ if (csum && skb_checksum_start(skb) < skb->data)
+ return -EINVAL;
return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
}

--
2.30.2


\
 
 \ /
  Last update: 2021-09-01 14:37    [W:0.403 / U:1.992 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site