From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 E090A5187DE; Wed, 30 Sep 2026 17:52:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790790766; cv=none; b=uurkahWqzdGSRFwT/BEPMaundHpKUHmedzjUTDWSolcAX5dm6hyEEk6B+tn9vp20fTYWlDplD9j/Z2Jv5/miMKsaOnEs3R8aiwftQiSlKCK1/QuYhnPtTMbBTSaEz4ZaGXM1gNd1zFGPOjoqmMqaKS0Vz+zJ6wP2PgS2WhNTrwU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790790766; c=relaxed/simple; bh=uFtFnyMeCpePzbjFrkcBK3YlCRXYTfWIhMrQyMjQlng=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Tnfs3poysKMyyERviKJ5jIVZWhMjO6ApoG8o/FsKY3uwdF8cxEt23SmaSFM0QU3oEpMB35vEpMSmg0DUK9FKwpBvRRedhpqwy3IR3iP11IpV8sIMtvzaq7gwdN5KBsPevkd2mfPKrFq6ueOTIbitOG/ZGFdhNb60PJgeuXs0Rac= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=A92qtJIm; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="A92qtJIm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4869D1F000FF; Wed, 30 Sep 2026 17:52:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790790764; bh=cTX7nZYKchaz3h2bir9uC9lZhuANjBDRqUwB5hdCDYM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=A92qtJImZKVY/XEWlzg+mQDdscuS03ezCL5JzDh1/kOxz3CYksu5V8LjJy58UTZh7 bHvjxCdp8d7Joo4b1tORxVgewUWSb7v9EBbBWGZejqnAu0/Tu7l3H0AYfE8QTytTqf DXTAQmTFjwBgc16toy9r7ifnr0iyrqNix1QA8S6o= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+fbf3648ae7f5bdb05c59@syzkaller.appspotmail.com, Jiayuan Chen , Allison Henderson , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 065/752] rds: annotate data-race around rs_seen_congestion Date: Wed, 30 Sep 2026 17:18:55 +0200 Message-ID: <20260930152359.568996800@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152358.131179731@linuxfoundation.org> References: <20260930152358.131179731@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiayuan Chen [ Upstream commit 67636cab273ed0c0b0f2adab6c9369a471cb7966 ] rs_seen_congestion is read in rds_poll() and written in rds_sendmsg() and rds_poll() without any lock. Use READ_ONCE()/WRITE_ONCE() to annotate these lockless accesses and silence KCSAN. Reported-by: syzbot+fbf3648ae7f5bdb05c59@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6a0f8d94.050a0220.6b33c.0000.GAE@google.com/ Signed-off-by: Jiayuan Chen Reviewed-by: Allison Henderson   Tested-by: Allison Henderson Link: https://patch.msgid.link/20260522011621.304470-1-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/rds/af_rds.c | 4 ++-- net/rds/send.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/net/rds/af_rds.c b/net/rds/af_rds.c index 9165d054e8e35..5fc38d2b411d5 100644 --- a/net/rds/af_rds.c +++ b/net/rds/af_rds.c @@ -217,7 +217,7 @@ static __poll_t rds_poll(struct file *file, struct socket *sock, poll_wait(file, sk_sleep(sk), wait); - if (rs->rs_seen_congestion) + if (READ_ONCE(rs->rs_seen_congestion)) poll_wait(file, &rds_poll_waitq, wait); read_lock_irqsave(&rs->rs_recv_lock, flags); @@ -245,7 +245,7 @@ static __poll_t rds_poll(struct file *file, struct socket *sock, /* clear state any time we wake a seen-congested socket */ if (mask) - rs->rs_seen_congestion = 0; + WRITE_ONCE(rs->rs_seen_congestion, 0); return mask; } diff --git a/net/rds/send.c b/net/rds/send.c index 9a23f8f2bcfa7..22b41745c6eb5 100644 --- a/net/rds/send.c +++ b/net/rds/send.c @@ -1340,7 +1340,7 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len) ret = rds_cong_wait(conn->c_fcong, dport, nonblock, rs); if (ret) { - rs->rs_seen_congestion = 1; + WRITE_ONCE(rs->rs_seen_congestion, 1); goto out; } while (!rds_send_queue_rm(rs, conn, cpath, rm, rs->rs_bound_port, -- 2.53.0