diff options
| author | Eric Dumazet <edumazet@google.com> | 2026-02-26 09:40:36 +0000 |
|---|---|---|
| committer | Florian Westphal <fw@strlen.de> | 2026-03-04 11:45:44 +0100 |
| commit | 013e2f91d0a4cac7396ac121ecdbc7bb71ca5cef (patch) | |
| tree | cf803fbb5f93a544dcbf0ae125c39fb4bc5929d5 /net | |
| parent | b297aaefc648be6bd6f3028f0b6161707c7bf632 (diff) | |
| download | linux-013e2f91d0a4cac7396ac121ecdbc7bb71ca5cef.tar.gz linux-013e2f91d0a4cac7396ac121ecdbc7bb71ca5cef.zip | |
netfilter: nfnetlink_queue: no longer acquire sk_callback_lock
After commit 983512f3a87f ("net: Drop the lock in skb_may_tx_timestamp()")
from Sebastian Andrzej Siewior, apply the same logic in
nfqnl_put_sk_uidgid() to avoid touching sk->sk_callback_lock.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nfnetlink_queue.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index 7f5248b5f1ee..27300d3663da 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -545,14 +545,23 @@ nfqnl_put_packet_info(struct sk_buff *nlskb, struct sk_buff *packet, static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk) { + const struct socket *sock; + const struct file *file; const struct cred *cred; if (!sk_fullsock(sk)) return 0; - read_lock_bh(&sk->sk_callback_lock); - if (sk->sk_socket && sk->sk_socket->file) { - cred = sk->sk_socket->file->f_cred; + /* The sk pointer remains valid as long as the skb is. + * The sk_socket and file pointer may become NULL + * if the socket is closed. + * Both structures (including file->cred) are RCU freed + * which means they can be accessed within a RCU read section. + */ + sock = READ_ONCE(sk->sk_socket); + file = sock ? READ_ONCE(sock->file) : NULL; + if (file) { + cred = file->f_cred; if (nla_put_be32(skb, NFQA_UID, htonl(from_kuid_munged(&init_user_ns, cred->fsuid)))) goto nla_put_failure; @@ -560,11 +569,9 @@ static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk) htonl(from_kgid_munged(&init_user_ns, cred->fsgid)))) goto nla_put_failure; } - read_unlock_bh(&sk->sk_callback_lock); return 0; nla_put_failure: - read_unlock_bh(&sk->sk_callback_lock); return -1; } |