xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

ipv4: properly combine dev_base_seq and ipv4.dev_addr_genid

Browse Source 
[ Upstream commit 081a0e3b0d4c061419d3f4679dec9f68725b17e4 ]

net->dev_base_seq and ipv4.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: 0465277f6b ("ipv4: provide addr and netconf dump consistency info")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.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>
This commit is contained in:
Eric Dumazet
2024-02-15 17:21:06 +00:00
committed by Greg Kroah-Hartman
parent fc30793e06
commit dcc1375d41
1 changed files with 17 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
net/ipv4/devinet.c
View File

@@ -1798,6 +1798,21 @@ done:
return err; return err;
} }
/* Combine dev_addr_genid and dev_base_seq to detect changes.
*/
static u32 inet_base_seq(const struct net *net)
{
u32 res = atomic_read(&net->ipv4.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 inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb) static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
{ {
const struct nlmsghdr *nlh = cb->nlh; const struct nlmsghdr *nlh = cb->nlh;
@@ -1849,8 +1864,7 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
idx = 0; idx = 0;
head = &tgt_net->dev_index_head[h]; head = &tgt_net->dev_index_head[h];
rcu_read_lock(); rcu_read_lock();
cb->seq = atomic_read(&tgt_net->ipv4.dev_addr_genid) ^ cb->seq = inet_base_seq(tgt_net);
tgt_net->dev_base_seq;
hlist_for_each_entry_rcu(dev, head, index_hlist) { hlist_for_each_entry_rcu(dev, head, index_hlist) {
if (idx < s_idx) if (idx < s_idx)
goto cont; goto cont;
@@ -2249,8 +2263,7 @@ static int inet_netconf_dump_devconf(struct sk_buff *skb,
idx = 0; idx = 0;
head = &net->dev_index_head[h]; head = &net->dev_index_head[h];
rcu_read_lock(); rcu_read_lock();
cb->seq = atomic_read(&net->ipv4.dev_addr_genid) ^ cb->seq = inet_base_seq(net);
net->dev_base_seq;
hlist_for_each_entry_rcu(dev, head, index_hlist) { hlist_for_each_entry_rcu(dev, head, index_hlist) {
if (idx < s_idx) if (idx < s_idx)
goto cont; goto cont;