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inet: annotate data-races around ifa->ifa_tstamp and ifa->ifa_cstamp

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ifa->ifa_tstamp can be read locklessly.

Add appropriate READ_ONCE()/WRITE_ONCE() annotations.

Do the same for ifa->ifa_cstamp to prepare upcoming changes.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2024-02-29 11:40:11 +00:00 committed by David S. Miller
parent 76f06cbd7b
commit 3cd3e72ccb
1 changed files with 13 additions and 10 deletions
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23
net/ipv4/devinet.c
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@ -713,13 +713,14 @@ static void check_lifetime(struct work_struct *work)
rcu_read_lock();
hlist_for_each_entry_rcu(ifa, &inet_addr_lst[i], hash) {
unsigned long age;
unsigned long age, tstamp;
if (ifa->ifa_flags & IFA_F_PERMANENT)
continue;
tstamp = READ_ONCE(ifa->ifa_tstamp);
/* We try to batch several events at once. */
age = (now - ifa->ifa_tstamp +
age = (now - tstamp +
ADDRCONF_TIMER_FUZZ_MINUS) / HZ;
if (ifa->ifa_valid_lft != INFINITY_LIFE_TIME &&
@ -729,17 +730,17 @@ static void check_lifetime(struct work_struct *work)
INFINITY_LIFE_TIME) {
continue;
} else if (age >= ifa->ifa_preferred_lft) {
if (time_before(ifa->ifa_tstamp +
if (time_before(tstamp +
ifa->ifa_valid_lft * HZ, next))
next = ifa->ifa_tstamp +
next = tstamp +
ifa->ifa_valid_lft * HZ;
if (!(ifa->ifa_flags & IFA_F_DEPRECATED))
change_needed = true;
} else if (time_before(ifa->ifa_tstamp +
} else if (time_before(tstamp +
ifa->ifa_preferred_lft * HZ,
next)) {
next = ifa->ifa_tstamp +
next = tstamp +
ifa->ifa_preferred_lft * HZ;
}
}
@ -819,9 +820,9 @@ static void set_ifa_lifetime(struct in_ifaddr *ifa, __u32 valid_lft,
ifa->ifa_flags |= IFA_F_DEPRECATED;
ifa->ifa_preferred_lft = timeout;
}
ifa->ifa_tstamp = jiffies;
WRITE_ONCE(ifa->ifa_tstamp, jiffies);
if (!ifa->ifa_cstamp)
ifa->ifa_cstamp = ifa->ifa_tstamp;
WRITE_ONCE(ifa->ifa_cstamp, ifa->ifa_tstamp);
}
static struct in_ifaddr *rtm_to_ifaddr(struct net *net, struct nlmsghdr *nlh,
@ -1676,6 +1677,7 @@ static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa,
{
struct ifaddrmsg *ifm;
struct nlmsghdr *nlh;
unsigned long tstamp;
u32 preferred, valid;
nlh = nlmsg_put(skb, args->portid, args->seq, args->event, sizeof(*ifm),
@ -1694,11 +1696,12 @@ static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa,
nla_put_s32(skb, IFA_TARGET_NETNSID, args->netnsid))
goto nla_put_failure;
tstamp = READ_ONCE(ifa->ifa_tstamp);
if (!(ifm->ifa_flags & IFA_F_PERMANENT)) {
preferred = ifa->ifa_preferred_lft;
valid = ifa->ifa_valid_lft;
if (preferred != INFINITY_LIFE_TIME) {
long tval = (jiffies - ifa->ifa_tstamp) / HZ;
long tval = (jiffies - tstamp) / HZ;
if (preferred > tval)
preferred -= tval;
@ -1728,7 +1731,7 @@ static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa,
nla_put_u32(skb, IFA_FLAGS, ifa->ifa_flags) ||
(ifa->ifa_rt_priority &&
nla_put_u32(skb, IFA_RT_PRIORITY, ifa->ifa_rt_priority)) ||
put_cacheinfo(skb, ifa->ifa_cstamp, ifa->ifa_tstamp,
put_cacheinfo(skb, READ_ONCE(ifa->ifa_cstamp), tstamp,
preferred, valid))
goto nla_put_failure;