From nobody Sat Jul 25 03:04:12 2026 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 770A63CC7CD; Mon, 20 Jul 2026 08:22:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.3 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784535749; cv=none; b=UTRTDXs3DkInU3FgyP5qSB8ld9T29xkDJuseqf94G4gujlJ/mnLsNVOtLkLFVuL+Uq5iyzklvIDz5GL9cZ/Ixw9WUvJHKfxnKq6IsUhWiYBZXQFNvGG7El5Dnk9qltxSziPT0JglRnfvSCJOq8guBWZ1H/f8O1Tz1aTejJ92idc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784535749; c=relaxed/simple; bh=ySEwroPRb5DHlyaq4soxUzkTKQt+T8Sec43Br85Lu5M=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=p/FuMtgZhd/M13x7hKW4qETvDNdr+y8mFJwHpUGfR3XLI4lc1tLFRtGXP8SnIBUGQ9GeX4oU2HqcwX3S6ZoKYW/WE1QxNaW54QYtzyWib9xo1KM0ZtRn6TVd8K9cfX2I2mHNZxfNfquejYJRJcXPRmY2ycNRV/5W5yeCgWZ5XZI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=CrlMW0M0; arc=none smtp.client-ip=220.197.31.3 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="CrlMW0M0" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=Jc wHsY5zypMELrWEKa1Ep6tVBSBTsXsnGhc31N6FYz0=; b=CrlMW0M01HTlIiij65 UHL8aGC2hXrF+dEtvVZFYPXp0ehPe+lR+q6SMMWaqRG3Mml8GpWxfSY5O5h8s+Jc P07C8PpQh4EnzTtUyaVCKUa53E/u4hhALhvs/bnERTCz6t/b05aX48pUadxJ5wJV NZG6lCbb0PtmwIPMv6UFte8Po= Received: from localhost.localdomain (unknown []) by gzga-smtp-mtada-g0-3 (Coremail) with SMTP id _____wCnM1uZ2l1qpi5jKg--.47708S2; Mon, 20 Jul 2026 16:21:46 +0800 (CST) From: luoqing To: marcelo.leitner@gmail.com, lucien.xin@gmail.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: horms@kernel.org, linux-sctp@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net v4] sctp: socket: refactor sctp_skb_recv_datagram to use ERR_PTR Date: Mon, 20 Jul 2026 16:21:45 +0800 Message-Id: <20260720082145.1072547-1-l1138897701@163.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: _____wCnM1uZ2l1qpi5jKg--.47708S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxXw18ZryUCF4Duw4ruFyrtFb_yoWrGrW3pF n8AFZ8JrWDJrW8uwnakFWkX3WrK3yrJ3y5Ca4rtw1Fyrs8Gr95tFyYgr4SkF45Cr4rCa4a qr4qgw1akrnruFDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07UDxhJUUUUU= X-CM-SenderInfo: jorrjmiyzxliqr6rljoofrz/xtbC3hrOE2pd2poyVwAA3L Content-Type: text/plain; charset="utf-8" From: Qing Luo The err output parameter in sctp_skb_recv_datagram() is passed to callers but never validated, making error reporting unreliable. Remove it and use ERR_PTR to encode errors directly in the return value, which is the standard kernel pattern for this case. Signed-off-by: Qing Luo --- include/net/sctp/sctp.h | 2 +- net/sctp/socket.c | 20 ++++++++++---------- net/sctp/ulpevent.c | 5 ++--- 3 files changed, 13 insertions(+), 14 deletions(-) diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index d50c27812504..b86d50d6b146 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -97,7 +97,7 @@ void sctp_sock_rfree(struct sk_buff *skb); =20 extern struct percpu_counter sctp_sockets_allocated; int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *); -struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int *); +struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags); =20 typedef int (*sctp_callback_t)(struct sctp_endpoint *, struct sctp_transpo= rt *, void *); void sctp_transport_walk_start(struct rhashtable_iter *iter); diff --git a/net/sctp/socket.c b/net/sctp/socket.c index c7b9e325ec1c..2deaa498e6cf 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -2123,9 +2123,11 @@ static int sctp_recvmsg(struct sock *sk, struct msgh= dr *msg, size_t len, goto out; } =20 - skb =3D sctp_skb_recv_datagram(sk, flags, &err); - if (!skb) + skb =3D sctp_skb_recv_datagram(sk, flags); + if (IS_ERR(skb)) { + err =3D PTR_ERR(skb); goto out; + } =20 /* Get the total length of the skb including any skb's in the * frag_list. @@ -9082,7 +9084,7 @@ static int sctp_wait_for_packet(struct sock *sk, int = *err, long *timeo_p) * Note: This is pretty much the same routine as in core/datagram.c * with a few changes to make lksctp work. */ -struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags, int *er= r) +struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags) { int error; struct sk_buff *skb; @@ -9117,21 +9119,19 @@ struct sk_buff *sctp_skb_recv_datagram(struct sock = *sk, int flags, int *err) if (error) goto no_packet; =20 - if (sk->sk_shutdown & RCV_SHUTDOWN) + if (sk->sk_shutdown & RCV_SHUTDOWN) { + error =3D 0; break; - + } =20 /* User doesn't want to wait. */ error =3D -EAGAIN; if (!timeo) goto no_packet; - } while (sctp_wait_for_packet(sk, err, &timeo) =3D=3D 0); - - return NULL; + } while (sctp_wait_for_packet(sk, &error, &timeo) =3D=3D 0); =20 no_packet: - *err =3D error; - return NULL; + return ERR_PTR(error); } =20 /* If sndbuf has changed, wake up per association sndbuf waiters. */ diff --git a/net/sctp/ulpevent.c b/net/sctp/ulpevent.c index 8920ca92a011..21ae0adbaeef 100644 --- a/net/sctp/ulpevent.c +++ b/net/sctp/ulpevent.c @@ -1061,10 +1061,9 @@ void sctp_ulpevent_read_nxtinfo(const struct sctp_ul= pevent *event, struct sock *sk) { struct sk_buff *skb; - int err; =20 - skb =3D sctp_skb_recv_datagram(sk, MSG_PEEK | MSG_DONTWAIT, &err); - if (skb !=3D NULL) { + skb =3D sctp_skb_recv_datagram(sk, MSG_PEEK | MSG_DONTWAIT); + if (!IS_ERR_OR_NULL(skb)) { __sctp_ulpevent_read_nxtinfo(sctp_skb2event(skb), msghdr, skb); /* Just release refcount here. */ --=20 2.25.1 >> I think it's used at [1] in sctp_recvmsg(): >> >> skb =3D sctp_skb_recv_datagram(sk, flags, &err); >> if (!skb) >> goto out; > Would it make more sense to ERR_PTR() etc ? > > > David Yes, you are right. The current implementation returns a negative error code directly via err, but it would be cleaner to use ERR_PTR() to unify the error path with other datagram receivers. I will refactor this part in v4: > > >> ... >> >> out: >> release_sock(sk); >> return err; <------ [1]