diff options
| author | Eric Dumazet <edumazet@google.com> | 2026-02-26 08:58:16 +0000 |
|---|---|---|
| committer | Florian Westphal <fw@strlen.de> | 2026-03-04 11:45:44 +0100 |
| commit | b297aaefc648be6bd6f3028f0b6161707c7bf632 (patch) | |
| tree | fb1d0ba8f5eedd99d965f8adaf2edbbbfb60c516 /net | |
| parent | afc2125de7414be3a31f5c09724c0375a57f5eae (diff) | |
netfilter: nfnetlink_log: 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
__build_packet_message() 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_log.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c index b35a90955e2e..730c2541a849 100644 --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -611,19 +611,26 @@ __build_packet_message(struct nfnl_log_net *log, /* UID */ sk = skb->sk; if (sk && sk_fullsock(sk)) { - read_lock_bh(&sk->sk_callback_lock); - if (sk->sk_socket && sk->sk_socket->file) { - struct file *file = sk->sk_socket->file; + const struct socket *sock; + const struct file *file; + + /* 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) { const struct cred *cred = file->f_cred; struct user_namespace *user_ns = inst->peer_user_ns; __be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid)); __be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid)); - read_unlock_bh(&sk->sk_callback_lock); if (nla_put_be32(inst->skb, NFULA_UID, uid) || nla_put_be32(inst->skb, NFULA_GID, gid)) goto nla_put_failure; - } else - read_unlock_bh(&sk->sk_callback_lock); + } } /* local sequence number */ |