From: David Ahern <dsahern@kernel.org>
To: Jakub Kicinski <kuba@kernel.org>, davem@davemloft.net
Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com,
andrew+netdev@lunn.ch, horms@kernel.org
Subject: Re: [PATCH net] ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu()
Date: Sun, 1 Mar 2026 18:38:53 -0700 [thread overview]
Message-ID: <859d39ff-cb1e-4f3f-b154-d8bf2c7997c9@kernel.org> (raw)
In-Reply-To: <20260301194548.927324-1-kuba@kernel.org>
On 3/1/26 12:45 PM, Jakub Kicinski wrote:
> diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> index 85df25c36409..7db0c837196c 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -1063,7 +1063,8 @@ static struct net_device *ip6_rt_get_dev_rcu(const struct fib6_result *res)
> */
> if (netif_is_l3_slave(dev) &&
> !rt6_need_strict(&res->f6i->fib6_dst.addr))
> - dev = l3mdev_master_dev_rcu(dev);
> + dev = l3mdev_master_dev_rcu(dev) ? :
> + dev_net(dev)->loopback_dev;
how can the flag on the netdev say there is L3 master, yet the device
not be there within an rcu window?
> else if (!netif_is_l3_master(dev))
> dev = dev_net(dev)->loopback_dev;
> /* last case is netif_is_l3_master(dev) is true in which
next prev parent reply other threads:[~2026-03-02 1:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-01 19:45 [PATCH net] ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu() Jakub Kicinski
2026-03-02 1:38 ` David Ahern [this message]
2026-03-02 14:43 ` Jakub Kicinski
2026-03-03 0:09 ` David Ahern
2026-03-04 1:30 ` patchwork-bot+netdevbpf
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