From: Gaurav Singh <gaurav1086@gmail.com>
To: gaurav1086@gmail.com, "David S. Miller" <davem@davemloft.net>,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
Jakub Kicinski <kuba@kernel.org>, Shaohua Li <shli@fb.com>,
netdev@vger.kernel.org (open list:NETWORKING [IPv4/IPv6]),
linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] [net/ipv6] ip6_output: Add ipv6_pinfo null check
Date: Sat, 8 Aug 2020 13:06:52 -0400 [thread overview]
Message-ID: <20200808170653.8515-1-gaurav1086@gmail.com> (raw)
In-Reply-To: <20200728021348.4116-1-gaurav1086@gmail.com>
This PR fixes a possible segmentation violation.
In function: ip6_xmit(), we have
const struct ipv6_pinfo *np = inet6_sk(sk); which returns NULL
unconditionally (regardless sk being NULL or not).
In include/linux/ipv6.h:
static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
{
return NULL;
}
Further down the function, there's a check:
if (np) hlimit = hp->htop_limit
Thereafter, we have a call
ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel,
ip6_autoflowlabel(net, np), fl6));
Hence np = NULL gets passed in
the function ip6_autoflowlabel() that accesses np without check which
may cause a segment violation.
Fixes: 513674b5a2c9c ("net: reevalulate autoflowlabel setting after sysctl setting")
Signed-off-by: Gaurav Singh <gaurav1086@gmail.com>
---
net/ipv6/ip6_output.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 8a8c2d0cfcc8..94a07c9bd925 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -181,10 +181,10 @@ int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np)
{
- if (!np->autoflowlabel_set)
- return ip6_default_np_autolabel(net);
- else
+ if (np && np->autoflowlabel_set)
return np->autoflowlabel;
+ else
+ return ip6_default_np_autolabel(net);
}
/*
--
2.17.1
next prev parent reply other threads:[~2020-08-08 17:07 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-27 3:38 [PATCH] [net/ipv6] ip6_output: Add ipv6_pinfo null check Gaurav Singh
2020-07-27 5:18 ` kernel test robot
2020-07-27 10:34 ` kernel test robot
2020-07-27 18:39 ` David Miller
2020-07-27 19:50 ` Cong Wang
2020-07-28 2:13 ` Gaurav Singh
2020-07-28 3:12 ` Cong Wang
2020-07-28 14:41 ` Eric Dumazet
2020-08-08 17:06 ` Gaurav Singh [this message]
2020-08-08 17:37 ` Cong Wang
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