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authorEric Dumazet <edumazet@google.com>2025-08-28 19:58:20 +0000
committerJakub Kicinski <kuba@kernel.org>2025-08-29 19:36:32 -0700
commit99a2ace61b211b0be861b07fbaa062fca4b58879 (patch)
tree12caebe1df6c6c329c3206be82c95a7348110045 /net/core
parentipv6: use RCU in ip6_output() (diff)
downloadlinux-99a2ace61b211b0be861b07fbaa062fca4b58879.tar.gz
linux-99a2ace61b211b0be861b07fbaa062fca4b58879.zip
net: use dst_dev_rcu() in sk_setup_caps()
Use RCU to protect accesses to dst->dev from sk_setup_caps() and sk_dst_gso_max_size(). Also use dst_dev_rcu() in ip6_dst_mtu_maybe_forward(), and ip_dst_mtu_maybe_forward(). ip4_dst_hoplimit() can use dst_dev_net_rcu(). Fixes: 4a6ce2b6f2ec ("net: introduce a new function dst_dev_put()") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250828195823.3958522-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/sock.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/net/core/sock.c b/net/core/sock.c
index e66ad1ec3a2d..9a8290fcc35d 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2587,7 +2587,7 @@ free:
}
EXPORT_SYMBOL_GPL(sk_clone_lock);
-static u32 sk_dst_gso_max_size(struct sock *sk, struct dst_entry *dst)
+static u32 sk_dst_gso_max_size(struct sock *sk, const struct net_device *dev)
{
bool is_ipv6 = false;
u32 max_size;
@@ -2597,8 +2597,8 @@ static u32 sk_dst_gso_max_size(struct sock *sk, struct dst_entry *dst)
!ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr));
#endif
/* pairs with the WRITE_ONCE() in netif_set_gso(_ipv4)_max_size() */
- max_size = is_ipv6 ? READ_ONCE(dst_dev(dst)->gso_max_size) :
- READ_ONCE(dst_dev(dst)->gso_ipv4_max_size);
+ max_size = is_ipv6 ? READ_ONCE(dev->gso_max_size) :
+ READ_ONCE(dev->gso_ipv4_max_size);
if (max_size > GSO_LEGACY_MAX_SIZE && !sk_is_tcp(sk))
max_size = GSO_LEGACY_MAX_SIZE;
@@ -2607,9 +2607,12 @@ static u32 sk_dst_gso_max_size(struct sock *sk, struct dst_entry *dst)
void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
{
+ const struct net_device *dev;
u32 max_segs = 1;
- sk->sk_route_caps = dst_dev(dst)->features;
+ rcu_read_lock();
+ dev = dst_dev_rcu(dst);
+ sk->sk_route_caps = dev->features;
if (sk_is_tcp(sk)) {
struct inet_connection_sock *icsk = inet_csk(sk);
@@ -2625,13 +2628,14 @@ void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
} else {
sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
- sk->sk_gso_max_size = sk_dst_gso_max_size(sk, dst);
+ sk->sk_gso_max_size = sk_dst_gso_max_size(sk, dev);
/* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */
- max_segs = max_t(u32, READ_ONCE(dst_dev(dst)->gso_max_segs), 1);
+ max_segs = max_t(u32, READ_ONCE(dev->gso_max_segs), 1);
}
}
sk->sk_gso_max_segs = max_segs;
sk_dst_set(sk, dst);
+ rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(sk_setup_caps);