averello/linux-stable-mirror
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2026-07-08 18:13:59 +02:00
Code Issues Packages Projects Releases Wiki Activity

ipv4: properly combine dev_base_seq and ipv4.dev_addr_genid

Browse Source 
[ Upstream commit 081a0e3b0d ]

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 8e29f988ad
commit b43a4fb42f
1 changed files with 17 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files
net/ipv4/devinet.c
+17 -4
View File
@@ -1804,6 +1804,21 @@ done:
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)
{
const struct nlmsghdr *nlh = cb->nlh;
@@ -1855,8 +1870,7 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
idx = 0;
head = &tgt_net->dev_index_head[h];
rcu_read_lock();
cb->seq = atomic_read(&tgt_net->ipv4.dev_addr_genid) ^
tgt_net->dev_base_seq;
cb->seq = inet_base_seq(tgt_net);
hlist_for_each_entry_rcu(dev, head, index_hlist) {
if (idx < s_idx)
goto cont;
@@ -2257,8 +2271,7 @@ static int inet_netconf_dump_devconf(struct sk_buff *skb,
idx = 0;
head = &net->dev_index_head[h];
rcu_read_lock();
cb->seq = atomic_read(&net->ipv4.dev_addr_genid) ^
net->dev_base_seq;
cb->seq = inet_base_seq(net);
hlist_for_each_entry_rcu(dev, head, index_hlist) {
if (idx < s_idx)
goto cont;