From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f70.google.com (mail-oo1-f70.google.com [209.85.161.70]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3886E36D516 for ; Tue, 17 Feb 2026 16:08:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.70 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771344503; cv=none; b=QlskDpfzUpXUv+uDdD8ePhY5Hq9ZDG9v5frvNxzsfod98b8XTYWnNTo7B+is9FYujo1TPO84uK8DlSDq+joIk9KAB0V89f3YYVAlqEliFiLeMEfstxNy8j/u+hknfFd6J9LI3M8KoAfZogkHJXLfa7qq2uZgnxKdJNZhDiIZsQE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771344503; c=relaxed/simple; bh=JliyW7zepwjvQZbLMGbch8OU0DTaqQTYQv2hTda1lDU=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=gdF7nO4ZAKeSchLu/W8xKGHkvwSqag/XPZQjyYdclc62u5b7dpz6vemBJbc7IQLKXmrW/7fT+n3CUrpe37CupXOvzWj5EReJOsG8d7nUIAwEw94pfGBCNClBiY7v7+eitQVsc02id8Gi/pesbPflNeTWcr3erPgt8BCERXfjA40= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.161.70 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oo1-f70.google.com with SMTP id 006d021491bc7-6781479fe9dso46311332eaf.1 for ; Tue, 17 Feb 2026 08:08:22 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771344501; x=1771949301; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=UaZk6k1MJUvmTXwEbhhr17OQUKYfol3DA5TSzMsaSLM=; b=kAKZiOQceyXBTEBgNaHy5MAeFG9ri+7sNrfnmEVuGu9a0yFKAqESD6maaFWcIfxHwl prn8w25orvjw4R5b33czb8Awy9IzJgpHhiFfvrBTRMhKJA0rmRKdJV1qioEZ6XfVwj2k HYL/MiiJUZVxl22TJauvrxHCTaDDYHzfdgITEvBB1uLJjuXu/SXvMzwHSyyEq7Rm0Ip2 Fa3WNa26N2efWWGiaSt3N4xqWlBKkKo59O9+yr4i283nuB7NGTKeCuZGIqmFGJEXTW6r PBsE4oxBGcb1rmMmg+/pZ9sMXh3AVJX5ot8aMh7DdYoHOUC3luu4sSa+yMbVeG521XfM QJUA== X-Forwarded-Encrypted: i=1; AJvYcCXzxSaiT1yfmbKXA+w83WvsmIZxfkaBBAwTIK13xiDnVjlMd+As3UEgH67u1NZRSx5pC/dC6oY=@vger.kernel.org X-Gm-Message-State: AOJu0Yx6EH5eyaS+z+1tW2wbpbW37Kqu+kqGz0LxcBF9TFIuTqfVuq6+ uiOHwSfikSK0W1hvoxFQbaXm2VSPZybsGsjqwBq0ui7gwQn06/N9Y4I6nhGMwQ7E+68ycmhz4l4 EF6gUtd/pgliY1nHMv7/XMvCqvhWOhLEI2+PM/PXmE28QU3S8eCUZo7YttqE= Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:2283:b0:66e:b5fa:db0a with SMTP id 006d021491bc7-6781fff0e68mr6912382eaf.5.1771344501268; Tue, 17 Feb 2026 08:08:21 -0800 (PST) Date: Tue, 17 Feb 2026 08:08:21 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69949275.050a0220.2eeac1.0145.GAE@google.com> Subject: [syzbot] [net?] KCSAN: data-race in tcp_assign_congestion_control / tcp_v6_syn_recv_sock From: syzbot To: davem@davemloft.net, dsahern@kernel.org, edumazet@google.com, horms@kernel.org, kuba@kernel.org, kuniyu@google.com, linux-kernel@vger.kernel.org, ncardwell@google.com, netdev@vger.kernel.org, pabeni@redhat.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: cee73b1e840c Merge tag 'riscv-for-linus-7.0-mw1' of git://.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1188e15a580000 kernel config: https://syzkaller.appspot.com/x/.config?x=a6d4a8c8877f1220 dashboard link: https://syzkaller.appspot.com/bug?extid=937b5bbb6a815b3e5d0b compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/c607da3ff440/disk-cee73b1e.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/0ca19d705091/vmlinux-cee73b1e.xz kernel image: https://storage.googleapis.com/syzbot-assets/6c9182a73e86/bzImage-cee73b1e.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+937b5bbb6a815b3e5d0b@syzkaller.appspotmail.com ================================================================== BUG: KCSAN: data-race in tcp_assign_congestion_control / tcp_v6_syn_recv_sock read-write to 0xffff888103ccb073 of 1 bytes by interrupt on cpu 0: tcp_assign_congestion_control+0x2d3/0x310 net/ipv4/tcp_cong.c:-1 tcp_ca_openreq_child+0x196/0x1d0 net/ipv4/tcp_minisocks.c:522 tcp_v4_syn_recv_sock+0x4ce/0xa90 net/ipv4/tcp_ipv4.c:1760 tcp_v6_syn_recv_sock+0xb1/0xe70 net/ipv6/tcp_ipv6.c:1340 tcp_check_req+0xddd/0x1150 net/ipv4/tcp_minisocks.c:927 tcp_v4_rcv+0xeda/0x1d90 net/ipv4/tcp_ipv4.c:2238 ip_protocol_deliver_rcu+0x395/0x790 net/ipv4/ip_input.c:207 ip_local_deliver_finish+0x1fc/0x2f0 net/ipv4/ip_input.c:241 NF_HOOK include/linux/netfilter.h:318 [inline] ip_local_deliver+0xe8/0x1e0 net/ipv4/ip_input.c:262 dst_input include/net/dst.h:480 [inline] ip_rcv_finish+0x194/0x1c0 net/ipv4/ip_input.c:453 NF_HOOK include/linux/netfilter.h:318 [inline] ip_rcv+0x62/0x160 net/ipv4/ip_input.c:573 __netif_receive_skb_one_core net/core/dev.c:6149 [inline] __netif_receive_skb net/core/dev.c:6262 [inline] process_backlog+0x341/0x670 net/core/dev.c:6614 __napi_poll+0x5f/0x310 net/core/dev.c:7678 napi_poll net/core/dev.c:7741 [inline] net_rx_action+0x452/0x930 net/core/dev.c:7893 handle_softirqs+0xb9/0x280 kernel/softirq.c:622 do_softirq+0x45/0x60 kernel/softirq.c:523 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:924 [inline] __dev_queue_xmit+0x139a/0x1f20 net/core/dev.c:4856 dev_queue_xmit include/linux/netdevice.h:3384 [inline] neigh_hh_output include/net/neighbour.h:540 [inline] neigh_output include/net/neighbour.h:554 [inline] ip_finish_output2+0x705/0x8c0 net/ipv4/ip_output.c:237 __ip_finish_output net/ipv4/ip_output.c:-1 [inline] ip_finish_output+0x114/0x2a0 net/ipv4/ip_output.c:325 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0xbd/0x1c0 net/ipv4/ip_output.c:438 dst_output include/net/dst.h:470 [inline] ip_local_out net/ipv4/ip_output.c:131 [inline] __ip_queue_xmit+0xbb0/0xbf0 net/ipv4/ip_output.c:534 ip_queue_xmit+0x39/0x50 net/ipv4/ip_output.c:548 __tcp_transmit_skb+0x1af2/0x1f10 net/ipv4/tcp_output.c:1693 tcp_transmit_skb net/ipv4/tcp_output.c:1711 [inline] tcp_write_xmit+0x1597/0x3640 net/ipv4/tcp_output.c:3064 __tcp_push_pending_frames+0x6d/0x1b0 net/ipv4/tcp_output.c:3247 tcp_push_pending_frames include/net/tcp.h:2282 [inline] __tcp_sock_set_cork net/ipv4/tcp.c:3688 [inline] tcp_sock_set_cork+0xe1/0x100 net/ipv4/tcp.c:3695 rds_tcp_xmit_path_complete+0x3b/0x50 net/rds/tcp_send.c:52 rds_send_xmit+0x128c/0x16f0 net/rds/send.c:480 rds_send_worker+0x44/0x1b0 net/rds/threads.c:200 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0x4cd/0x9d0 kernel/workqueue.c:3358 worker_thread+0x581/0x770 kernel/workqueue.c:3439 kthread+0x22a/0x280 kernel/kthread.c:467 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 read to 0xffff888103ccb040 of 128 bytes by interrupt on cpu 1: tcp_v6_syn_recv_sock+0x103/0xe70 net/ipv6/tcp_ipv6.c:1353 tcp_check_req+0xddd/0x1150 net/ipv4/tcp_minisocks.c:927 tcp_v4_rcv+0xeda/0x1d90 net/ipv4/tcp_ipv4.c:2238 ip_protocol_deliver_rcu+0x395/0x790 net/ipv4/ip_input.c:207 ip_local_deliver_finish+0x1fc/0x2f0 net/ipv4/ip_input.c:241 NF_HOOK include/linux/netfilter.h:318 [inline] ip_local_deliver+0xe8/0x1e0 net/ipv4/ip_input.c:262 dst_input include/net/dst.h:480 [inline] ip_rcv_finish+0x194/0x1c0 net/ipv4/ip_input.c:453 NF_HOOK include/linux/netfilter.h:318 [inline] ip_rcv+0x62/0x160 net/ipv4/ip_input.c:573 __netif_receive_skb_one_core net/core/dev.c:6149 [inline] __netif_receive_skb net/core/dev.c:6262 [inline] process_backlog+0x341/0x670 net/core/dev.c:6614 __napi_poll+0x5f/0x310 net/core/dev.c:7678 napi_poll net/core/dev.c:7741 [inline] net_rx_action+0x452/0x930 net/core/dev.c:7893 handle_softirqs+0xb9/0x280 kernel/softirq.c:622 do_softirq+0x45/0x60 kernel/softirq.c:523 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:924 [inline] __dev_queue_xmit+0x139a/0x1f20 net/core/dev.c:4856 dev_queue_xmit include/linux/netdevice.h:3384 [inline] neigh_hh_output include/net/neighbour.h:540 [inline] neigh_output include/net/neighbour.h:554 [inline] ip_finish_output2+0x705/0x8c0 net/ipv4/ip_output.c:237 __ip_finish_output net/ipv4/ip_output.c:-1 [inline] ip_finish_output+0x114/0x2a0 net/ipv4/ip_output.c:325 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0xbd/0x1c0 net/ipv4/ip_output.c:438 dst_output include/net/dst.h:470 [inline] ip_local_out net/ipv4/ip_output.c:131 [inline] __ip_queue_xmit+0xbb0/0xbf0 net/ipv4/ip_output.c:534 ip_queue_xmit+0x39/0x50 net/ipv4/ip_output.c:548 __tcp_transmit_skb+0x1af2/0x1f10 net/ipv4/tcp_output.c:1693 tcp_transmit_skb net/ipv4/tcp_output.c:1711 [inline] tcp_write_xmit+0x1597/0x3640 net/ipv4/tcp_output.c:3064 __tcp_push_pending_frames+0x6d/0x1b0 net/ipv4/tcp_output.c:3247 tcp_send_fin+0x58a/0x6a0 net/ipv4/tcp_output.c:3846 __tcp_close+0x67d/0x1130 net/ipv4/tcp.c:3258 tcp_close+0x28/0xd0 net/ipv4/tcp.c:3349 inet_release+0xcd/0xf0 net/ipv4/af_inet.c:437 inet6_release+0x3e/0x60 net/ipv6/af_inet6.c:487 __sock_release net/socket.c:662 [inline] sock_release+0x4b/0xe0 net/socket.c:690 rds_tcp_accept_one+0x4a1/0x830 net/rds/tcp_listen.c:345 rds_tcp_accept_worker+0x1a/0x60 net/rds/tcp.c:524 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0x4cd/0x9d0 kernel/workqueue.c:3358 worker_thread+0x581/0x770 kernel/workqueue.c:3439 kthread+0x22a/0x280 kernel/kthread.c:467 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 1918 Comm: kworker/u8:5 Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: krdsd rds_tcp_accept_worker ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup