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 8161F3A4523; Thu, 17 Sep 2026 16:52:28 +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=1789663949; cv=none; b=CAtf3LMQwK4CNfRMUVqaY190sV2fUv0hQosGyqeQThKVubTzYB6oKRellbiS6dHEWc9tR1cAF8IHGMwCSx38yu29z2aIiGwXmVcpRIsOmRGzqqtHfviiPxUPnZCM7Igcbgd16NfipA4jgM1MNA/WQwP84hl8Z45Tx5igGjdBBVc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789663949; c=relaxed/simple; bh=y5J0WHvayeC2KvE2HrwI1qG44aGDRBMHMK9SNrejbYk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=bL71u1+/Oul7eUld9+2bIAxwaOHjLX9ADNOw8okh+gKYdbHbnLjn9O64RyPjDBO8nuhfEcpOVaWc6mwzsTQa8AiS3/8dP2lXlWvrAZtq62s48rckfj8RLnWg5Ze+H+fJt0gs+rJbddDvhuHB5WVcLqu3u4W39tggiHLxI39s8U0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=AZfhSeci; 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="AZfhSeci" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D917E1F000FF; Thu, 17 Sep 2026 16:52:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789663948; bh=NFyboFDeet7HhhlKb2PahRkO8B3j5Va/G1nTW4Y53Cw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=AZfhSeciWZ2764ud/emOByichVqhtskrJTdkb8LUdFRzvYEoxcs+920pPlxUQlvPh BSqgotvyTWloTK26ZP0TF5Iu/tuS/p6ayoyDmB3W8g9mU3lKO4i2dnHDcia59EjtnU ZE1+jYExReW0CdBzG0T/WAJegZ6IGLIlupEkX+V8= 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 6.18 0207/1250] rds: annotate data-race around rs_seen_congestion Date: Thu, 17 Sep 2026 16:00:02 +0100 Message-ID: <20260917151557.734103680@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260917151551.901433442@linuxfoundation.org> References: <20260917151551.901433442@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 6.18-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 cc3a898bf5d51..a9445937d225b 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 071c5dca969a2..d474c9cda65ae 100644 --- a/net/rds/send.c +++ b/net/rds/send.c @@ -1339,7 +1339,7 @@ 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