diff options
| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2022-07-13 23:51:53 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-07-29 18:19:12 +0300 |
| commit | b96ed5ccb09ae71103023ed13acefb194f609794 (patch) | |
| tree | d06f582f9e158920fce027c8efe74ad408ad68ff | |
| parent | 5e343e3ef464a5dbcc8fd3a99830908e31a4a61d (diff) | |
| download | linux-b96ed5ccb09ae71103023ed13acefb194f609794.tar.xz | |
ip: Fix data-races around sysctl_ip_fwd_use_pmtu.
[ Upstream commit 60c158dc7b1f0558f6cadd5b50d0386da0000d50 ]
While reading sysctl_ip_fwd_use_pmtu, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.
Fixes: f87c10a8aa1e ("ipv4: introduce ip_dst_mtu_maybe_forward and protect forwarding path against pmtu spoofing")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | include/net/ip.h | 2 | ||||
| -rw-r--r-- | net/ipv4/route.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/include/net/ip.h b/include/net/ip.h index 76aaa7eb5b82..a7e40ef02732 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -440,7 +440,7 @@ static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst, struct net *net = dev_net(dst->dev); unsigned int mtu; - if (net->ipv4.sysctl_ip_fwd_use_pmtu || + if (READ_ONCE(net->ipv4.sysctl_ip_fwd_use_pmtu) || ip_mtu_locked(dst) || !forwarding) return dst_mtu(dst); diff --git a/net/ipv4/route.c b/net/ipv4/route.c index aab8ac383d5d..374647693d7a 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1442,7 +1442,7 @@ u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) struct fib_info *fi = res->fi; u32 mtu = 0; - if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu || + if (READ_ONCE(dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu) || fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) mtu = fi->fib_mtu; |