6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mattia Meleleo [ Upstream commit 04af4efde58a4a4ef4feab7360c46af9ec0b83a0 ] tcp_bpf_ioctl() answers SIOCINQ from psock->msg_tot_len, which only counts bytes in ingress_msg. Without a stream/skb verdict program nothing is diverted there: data stays in sk_receive_queue, so FIONREAD returns 0 even though read() returns data. Add tcp_inq() to the reported value when the psock has no verdict program. The two queues are disjoint, so bytes redirected into ingress_msg from other sockets stay correctly accounted through msg_tot_len. Remove unused sk_psock_msg_inq(). Fixes: 929e30f93125 ("bpf, sockmap: Fix FIONREAD for sockmap") Signed-off-by: Mattia Meleleo Reviewed-by: Jiayuan Chen Reviewed-by: Emil Tsalapatis Reviewed-by: John Fastabend Link: https://lore.kernel.org/bpf/20260708-fionread-no-verdict-v3-1-b4ee31b3af53@coralogix.com Signed-off-by: Kumar Kartikeya Dwivedi Signed-off-by: Sasha Levin --- include/linux/skmsg.h | 14 -------------- net/ipv4/tcp_bpf.c | 17 ++++++++++++++++- 2 files changed, 16 insertions(+), 15 deletions(-) diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index 4ee7e4680a6e1..718351acd0230 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -561,20 +561,6 @@ static inline bool sk_psock_strp_enabled(struct sk_psock *psock) return !!psock->saved_data_ready; } -/* for tcp only, sk is locked */ -static inline ssize_t sk_psock_msg_inq(struct sock *sk) -{ - struct sk_psock *psock; - ssize_t inq = 0; - - psock = sk_psock_get(sk); - if (likely(psock)) { - inq = sk_psock_get_msg_len_nolock(psock); - sk_psock_put(sk, psock); - } - return inq; -} - /* for udp only, sk is not locked */ static inline ssize_t sk_msg_first_len(struct sock *sk) { diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index ca51756d8aa47..6027cd33a9fdc 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -334,6 +334,7 @@ static int tcp_bpf_recvmsg_parser(struct sock *sk, static int tcp_bpf_ioctl(struct sock *sk, int cmd, int *karg) { + struct sk_psock *psock; bool slow; if (cmd != SIOCINQ) @@ -344,7 +345,21 @@ static int tcp_bpf_ioctl(struct sock *sk, int cmd, int *karg) return -EINVAL; slow = lock_sock_fast(sk); - *karg = sk_psock_msg_inq(sk); + psock = sk_psock_get(sk); + if (unlikely(!psock)) { + unlock_sock_fast(sk, slow); + return tcp_ioctl(sk, cmd, karg); + } + *karg = sk_psock_get_msg_len_nolock(psock); + /* Without a verdict program, ingress data is never diverted to + * ingress_msg: it stays in sk_receive_queue and is read through + * the fallback to tcp_recvmsg(), so account for it like + * tcp_ioctl() does. + */ + if (!READ_ONCE(psock->progs.stream_verdict) && + !READ_ONCE(psock->progs.skb_verdict)) + *karg += tcp_inq(sk); + sk_psock_put(sk, psock); unlock_sock_fast(sk, slow); return 0; -- 2.53.0