diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-02-15 17:21:07 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-03-01 13:26:36 +0100 |
| commit | e5703735e57a3f1171b9b708f58850af55ef9602 (patch) | |
| tree | 4dbfd05124415c9d0c77a14d353096a4a65fe99c | |
| parent | b43a4fb42fefa69b00a4bc697c59b8107d9293cb (diff) | |
ipv6: properly combine dev_base_seq and ipv6.dev_addr_genid
[ Upstream commit e898e4cd1aab271ca414f9ac6e08e4c761f6913c ]
net->dev_base_seq and ipv6.dev_addr_genid are monotonically increasing.
If we XOR their values, we could miss to detect if both values
were changed with the same amount.
Fixes: 63998ac24f83 ("ipv6: provide addr and netconf dump consistency info")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | net/ipv6/addrconf.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index b8dc20fe7a4e..46527b5cc8f0 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -706,6 +706,22 @@ errout: return err; } +/* Combine dev_addr_genid and dev_base_seq to detect changes. + */ +static u32 inet6_base_seq(const struct net *net) +{ + u32 res = atomic_read(&net->ipv6.dev_addr_genid) + + net->dev_base_seq; + + /* Must not return 0 (see nl_dump_check_consistent()). + * Chose a value far away from 0. + */ + if (!res) + res = 0x80000000; + return res; +} + + static int inet6_netconf_dump_devconf(struct sk_buff *skb, struct netlink_callback *cb) { @@ -739,8 +755,7 @@ static int inet6_netconf_dump_devconf(struct sk_buff *skb, idx = 0; head = &net->dev_index_head[h]; rcu_read_lock(); - cb->seq = atomic_read(&net->ipv6.dev_addr_genid) ^ - net->dev_base_seq; + cb->seq = inet6_base_seq(net); hlist_for_each_entry_rcu(dev, head, index_hlist) { if (idx < s_idx) goto cont; @@ -5326,7 +5341,7 @@ static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, } rcu_read_lock(); - cb->seq = atomic_read(&tgt_net->ipv6.dev_addr_genid) ^ tgt_net->dev_base_seq; + cb->seq = inet6_base_seq(tgt_net); for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) { idx = 0; head = &tgt_net->dev_index_head[h]; |