From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f205.google.com (mail-oi1-f205.google.com [209.85.167.205]) (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 12A2B3101C0 for ; Fri, 31 Jul 2026 06:58:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.205 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785481104; cv=none; b=aS+3djSFLRltyGaPzRORGFvlfWMGpoFz3WtrLFoqV7CmsvijiH+H6U7tgHmgryYGklb+aCCKGZDX/67wVbRRo2jYpzAR7ANXaPl/bT8fsZ9/Y3ApuYdNBR38aWAmEqbPuBEtRwdG6ZLc99oQy6CSV91DJTVJGqlEztAKER/hE5g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785481104; c=relaxed/simple; bh=U/aUJssbFDVShhs3jI/L1wEPdHplGQXWwAdRRKJarH0=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=GK5HBNIepZ6qFHXg6qKOBPVPhGWOoxCSNl6PJaZIjoTrANoYDDwMAD4E2NamzuR/RvXsdbOH9Xg8dLdonhnNyIqQL9Vxus5pTWWXFZyfLzm0jM/3EJ8I6FteAHtaqr+pkdUbn588vR+2owJ5sJWo6hsMV2pXIlW0shn9oEgytOg= 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=209.85.167.205 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-oi1-f205.google.com with SMTP id 5614622812f47-49f3a97f1caso435775b6e.0 for ; Thu, 30 Jul 2026 23:58:22 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785481102; x=1786085902; h=content-type:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=lHauDrZbyLbJNwi2kBXhjYQh1jMBcJwNHp/E6dnN5vo=; b=DYLJfn5u9XQIa1k+vT01a3hb/QGKxKI0o+WKkLciSdCTYplf+XZ9FduxxwwSG6mYq+ 8RN/BkKAUtO2dV04cCw9Jmbkf0rqkWKYi3d3RjhiX+cZPcq0pkCQCX6GcsNbJ57ZUo4s ZRpmK7FBpiqpJTeP+UuJtmyDy0oyARcBkhCMLHJWhHfnUZltZ7MQhrgI2saAMxyTu/vB Jxl1osJaoRwx2KG/LXnqmO0kuH7uDrpPS68eDqjMXv6Sh0xipXWmCbxWs0O0Anf7JUIQ Aq0ZqeL6oJiJMAS3bJjvxLZmqSJW84AQ8/wKqUstZ48M0HM1MbXSgGccGPhwhZ62+tCv 6t5w== X-Forwarded-Encrypted: i=1; AHgh+RoLjhqEvtmq7B91x/xidoUSL2t4PDqyXe58YyYD7k1DZBrT/Z/5lzcoWoiev1hXrBf8qxH26IY=@vger.kernel.org X-Gm-Message-State: AOJu0YwGNbAwOMCHJPeVYIrGPt1v15svqOY4ebpqJYQKW//2kHQyDzSO JhoN8slsL9hI/U/WF8hbmEiXq6HiG7IQUtn0w08mfjYYCgH0ISXCechg83UdkZazXrhdMxrdpi5 vbOz0eEpG8zF0pysS5NF8my+e0+dIYp4iSEUZjZy3mgdAOz7uhb9G2o+HNFo= Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:1994:b0:4a4:af7f:83d3 with SMTP id 5614622812f47-4ae5ab9ef78mr727757b6e.20.1785481101937; Thu, 30 Jul 2026 23:58:21 -0700 (PDT) Date: Thu, 30 Jul 2026 23:58:21 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a6c478d.b5e7dbf9.21bf3.0007.GAE@google.com> Subject: [syzbot] [net?] WARNING: suspicious RCU usage in xfrm_nlmsg_multicast From: syzbot To: davem@davemloft.net, edumazet@google.com, herbert@gondor.apana.org.au, horms@kernel.org, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, steffen.klassert@secunet.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 4235cb24ec1e Merge tag 'vfs-7.2-rc5.fixes' of git://git.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=126091b9580000 kernel config: https://syzkaller.appspot.com/x/.config?x=cb17729fb04b1e3a dashboard link: https://syzkaller.appspot.com/bug?extid=c0e99a1aa85a286d7a3b compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16f16499580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14d5e6b9580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/34e9a122d3c0/disk-4235cb24.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/f5c47e8d86e0/vmlinux-4235cb24.xz kernel image: https://storage.googleapis.com/syzbot-assets/b287db60160f/bzImage-4235cb24.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+c0e99a1aa85a286d7a3b@syzkaller.appspotmail.com ============================= WARNING: suspicious RCU usage syzkaller #0 Not tainted ----------------------------- net/xfrm/xfrm_user.c:1630 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by syz.0.17/5947: #0: ffff888029cda048 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{4:4}, at: xfrm_netlink_rcv+0x6a/0x90 net/xfrm/xfrm_user.c:3928 stack backtrace: CPU: 1 UID: 0 PID: 5947 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x13f/0x1d0 kernel/locking/lockdep.c:6876 xfrm_nlmsg_multicast+0x1d8/0x1f0 net/xfrm/xfrm_user.c:1630 xfrm_send_migrate_state+0x870/0xae0 net/xfrm/xfrm_user.c:3340 xfrm_do_migrate_state+0x1749/0x1e90 net/xfrm/xfrm_user.c:3507 xfrm_user_rcv_msg+0x7a8/0xf30 net/xfrm/xfrm_user.c:3907 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 xfrm_netlink_rcv+0x79/0x90 net/xfrm/xfrm_user.c:3929 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7f5/0x990 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775 __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0x565/0x870 net/socket.c:2684 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738 __sys_sendmsg net/socket.c:2770 [inline] __do_sys_sendmsg net/socket.c:2775 [inline] __se_sys_sendmsg net/socket.c:2773 [inline] __x64_sys_sendmsg+0x1b7/0x290 net/socket.c:2773 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb235fede99 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc10a8b768 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fb236275fa0 RCX: 00007fb235fede99 RDX: 0000000000000000 RSI: 0000200000000500 RDI: 0000000000000003 RBP: 00007fb236083eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb236275fac R14: 00007fb236275fa0 R15: 00007fb236275fa0 --- 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 syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. 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