From 9f6fa3c4e722cbb9a007c3b85797bebfcdee84e9 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 29 Feb 2024 11:40:13 +0000 Subject: inet: annotate data-races around ifa->ifa_preferred_lft ifa->ifa_preferred_lft can be read locklessly. Add appropriate READ_ONCE()/WRITE_ONCE() annotations. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/devinet.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index 99f3e7c57d36..368fb56e1f1b 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -714,11 +714,13 @@ 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, tstamp; + u32 preferred_lft; u32 valid_lft; if (ifa->ifa_flags & IFA_F_PERMANENT) continue; + preferred_lft = READ_ONCE(ifa->ifa_preferred_lft); valid_lft = READ_ONCE(ifa->ifa_valid_lft); tstamp = READ_ONCE(ifa->ifa_tstamp); /* We try to batch several events at once. */ @@ -728,20 +730,18 @@ static void check_lifetime(struct work_struct *work) if (valid_lft != INFINITY_LIFE_TIME && age >= valid_lft) { change_needed = true; - } else if (ifa->ifa_preferred_lft == + } else if (preferred_lft == INFINITY_LIFE_TIME) { continue; - } else if (age >= ifa->ifa_preferred_lft) { + } else if (age >= preferred_lft) { if (time_before(tstamp + valid_lft * HZ, next)) next = tstamp + valid_lft * HZ; if (!(ifa->ifa_flags & IFA_F_DEPRECATED)) change_needed = true; - } else if (time_before(tstamp + - ifa->ifa_preferred_lft * HZ, + } else if (time_before(tstamp + preferred_lft * HZ, next)) { - next = tstamp + - ifa->ifa_preferred_lft * HZ; + next = tstamp + preferred_lft * HZ; } } rcu_read_unlock(); @@ -818,7 +818,7 @@ static void set_ifa_lifetime(struct in_ifaddr *ifa, __u32 valid_lft, if (addrconf_finite_timeout(timeout)) { if (timeout == 0) ifa->ifa_flags |= IFA_F_DEPRECATED; - ifa->ifa_preferred_lft = timeout; + WRITE_ONCE(ifa->ifa_preferred_lft, timeout); } WRITE_ONCE(ifa->ifa_tstamp, jiffies); if (!ifa->ifa_cstamp) @@ -1698,7 +1698,7 @@ static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa, tstamp = READ_ONCE(ifa->ifa_tstamp); if (!(ifm->ifa_flags & IFA_F_PERMANENT)) { - preferred = ifa->ifa_preferred_lft; + preferred = READ_ONCE(ifa->ifa_preferred_lft); valid = READ_ONCE(ifa->ifa_valid_lft); if (preferred != INFINITY_LIFE_TIME) { long tval = (jiffies - tstamp) / HZ; -- cgit v1.2.3