diff options
| author | Eric Dumazet <edumazet@google.com> | 2026-02-25 16:20:19 +0300 |
|---|---|---|
| committer | Florian Westphal <fw@strlen.de> | 2026-03-04 13:45:44 +0300 |
| commit | 5663ac3e548163183c4354e75f728f7b34ffe040 (patch) | |
| tree | 1a6644f8a91c7e14acea43343c71f54912acdc05 /net | |
| parent | 1c32b24c234ba88a969e6bd9c385e66212a4af15 (diff) | |
| download | linux-5663ac3e548163183c4354e75f728f7b34ffe040.tar.xz | |
netfilter: nf_log_syslog: no longer acquire sk_callback_lock in nf_log_dump_sk_uid_gid()
After commit 983512f3a87f ("net: Drop the lock in skb_may_tx_timestamp()")
from Sebastian Andrzej Siewior, apply the same logic in nf_log_dump_sk_uid_gid()
to avoid touching 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/nf_log_syslog.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/net/netfilter/nf_log_syslog.c b/net/netfilter/nf_log_syslog.c index 41503847d9d7..0507d67cad27 100644 --- a/net/netfilter/nf_log_syslog.c +++ b/net/netfilter/nf_log_syslog.c @@ -165,18 +165,26 @@ static struct nf_logger nf_arp_logger __read_mostly = { static void nf_log_dump_sk_uid_gid(struct net *net, struct nf_log_buf *m, struct sock *sk) { + const struct socket *sock; + const struct file *file; + if (!sk || !sk_fullsock(sk) || !net_eq(net, sock_net(sk))) return; - read_lock_bh(&sk->sk_callback_lock); - if (sk->sk_socket && sk->sk_socket->file) { - const struct cred *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) { + const struct cred *cred = file->f_cred; nf_log_buf_add(m, "UID=%u GID=%u ", from_kuid_munged(&init_user_ns, cred->fsuid), from_kgid_munged(&init_user_ns, cred->fsgid)); } - read_unlock_bh(&sk->sk_callback_lock); } static noinline_for_stack int |