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| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2022-07-13 13:51:53 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-07-15 11:49:55 +0100 |
| commit | 60c158dc7b1f0558f6cadd5b50d0386da0000d50 (patch) | |
| tree | 7f70607a57abd8881ac567ffdeb7f67c0960d47e /net/ipv4/route.c | |
| parent | 0968d2a441bf6afb551fd99e60fa65ed67068963 (diff) | |
| download | linux-60c158dc7b1f0558f6cadd5b50d0386da0000d50.tar.gz linux-60c158dc7b1f0558f6cadd5b50d0386da0000d50.tar.bz2 linux-60c158dc7b1f0558f6cadd5b50d0386da0000d50.zip | |
ip: Fix data-races around sysctl_ip_fwd_use_pmtu.
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>
Diffstat (limited to 'net/ipv4/route.c')
| -rw-r--r-- | net/ipv4/route.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 356f535f3443..91c4f60de75a 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1398,7 +1398,7 @@ 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; |