From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f206.google.com (mail-il1-f206.google.com [209.85.166.206]) (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 B7CBD14AD2B for ; Fri, 6 Jun 2025 14:56:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.206 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749221794; cv=none; b=u83fdTSdRkzmQpeA8McZre8i9ptc0wJUmcj3c5zhOB4ENV9Yi7pqlHnaiQIkDfhFyLZeNsivCiyy00zj9kCRnd1QHJzayS522Ni3i0zmWv4Iq4L2dVz8eUWpV69zdI4CVrLDyxT0MEHBtzzJEaAv8/jDzkSZlUXj0Xbh1IqlYhI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749221794; c=relaxed/simple; bh=Un6/u1lqCJMKeoiAiYXzAp6NLdokv78xP3NcfhlOiFM=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=tfjEegry8jZX25c+gYGK1QwT8AbK0LksDTO16jg4BEVMD52wYclXm28AZjrFFbmZqs8ZZ3pNQSJtdV24r4FFqJfI4UftQO65GVu8AJ6eGifLOrIX3Su+KTOpRMD3LMLz2S2AuhkglUMQObDjLbLHlflftwUYL0eEVUqb8kKHBCg= 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=209.85.166.206 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-il1-f206.google.com with SMTP id e9e14a558f8ab-3ddc147611fso44508555ab.3 for ; Fri, 06 Jun 2025 07:56:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1749221792; x=1749826592; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=YF+eXovpI+BPFHViBf5OAfiZKlMj7V/t4795WnL00rU=; b=U4kBI6PCNs94JKfyk4HjNBQoiHWY14XVJYauS5wGgjygwWM6keQUWshpsD40ucEiUQ JvDVTVJ60Y+MDY1MUc9HBzazZLZnU3f/nEA8WC8gmP9pVJUVZWEXZFZ+0eWmhNg4OvfV 1EZfH3sGfYJq1q8lKTBYGziGmnCNivD6ZQvYZwmBL/B67QiYHRXoee1xrm2IJ+BDSc9D /G+akuvkvuVr8Y7C5JkePQRdWVha95n3i3dpCC0mUDWCQnJB5S84eHWBym6x3Mz9NLNC 4ruRpsgJE+UBptnKyyghl2mEXUa7J2g3l7Fi9MUIGawe3ZWnR9gojG9JQlzTFcmhG62a HrdA== X-Forwarded-Encrypted: i=1; AJvYcCXS4sATYfwNrSSCRbWHdb9FkeVrn4qgyG/Y7yXuzxQs7xFsM/lmlyT1CSdiIIqJRmfjO1o+b5k=@vger.kernel.org X-Gm-Message-State: AOJu0Ywb5tS3vICcC/yD34iKVNtI6ZZad2G12dNZSo0Ufz7Punsf0+Pb 2ASDg62PITlmpHmkGZpagAr2iFmNXXj2OqOT3yTRI52lLqZ20nQlhNfEBy83q+uM/GGgWQVH7az MmCvimqo2sXTHB09ekw8aLepdtIahd0dU6iaF2njYjlcEUhF8kPuINlUPFgQ= X-Google-Smtp-Source: AGHT+IFoFrrAmYlUpTD7FdSKQo72bN7Yrvawlqt2K4lsdzd6TpbdcCvkEx3s0/p4fEZWZ1kM1Nfeko7FkjTGgW4lQtakoFYCEXF7 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:4416:10b0:3dd:d348:715a with SMTP id e9e14a558f8ab-3ddd3487186mr12124125ab.8.1749221791701; Fri, 06 Jun 2025 07:56:31 -0700 (PDT) Date: Fri, 06 Jun 2025 07:56:31 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6843019f.a00a0220.29ac89.0044.GAE@google.com> Subject: [syzbot] [net?] WARNING: refcount bug in gro_cleanup From: syzbot To: davem@davemloft.net, edumazet@google.com, horms@kernel.org, kuba@kernel.org, linux-kernel@vger.kernel.org, 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: d0c22de9995b Merge tag 'input-for-v6.15-rc7' of git://git... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1745b5f4580000 kernel config: https://syzkaller.appspot.com/x/.config?x=9fd1c9848687d742 dashboard link: https://syzkaller.appspot.com/bug?extid=9de2587cce48f5642f16 compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/b862906e9f4b/disk-d0c22de9.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/c0d716f15db2/vmlinux-d0c22de9.xz kernel image: https://storage.googleapis.com/syzbot-assets/7ffe8e4af4ec/bzImage-d0c22de9.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+9de2587cce48f5642f16@syzkaller.appspotmail.com ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 8170 at lib/refcount.c:28 refcount_warn_saturate+0x11a/0x1d0 lib/refcount.c:28 Modules linked in: CPU: 1 UID: 0 PID: 8170 Comm: syz.4.605 Not tainted 6.15.0-rc7-syzkaller-00152-gd0c22de9995b #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:refcount_warn_saturate+0x11a/0x1d0 lib/refcount.c:28 Code: 80 aa c1 8b e8 e7 52 cb fc 90 0f 0b 90 90 eb d7 e8 4b f6 06 fd c6 05 67 3c b0 0a 01 90 48 c7 c7 e0 aa c1 8b e8 c7 52 cb fc 90 <0f> 0b 90 90 eb b7 e8 2b f6 06 fd c6 05 44 3c b0 0a 01 90 48 c7 c7 RSP: 0018:ffffc9000419f628 EFLAGS: 00010246 RAX: b3f3c577eef85a00 RBX: 0000000000000003 RCX: 0000000000080000 RDX: ffffc9001071e000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: 0000000000000000 R08: ffffffff8f7f3577 R09: 1ffffffff1efe6ae R10: dffffc0000000000 R11: fffffbfff1efe6af R12: dffffc0000000000 R13: 4888ffffe8ffffc8 R14: ffffe8ffffc8496e R15: ffffe8ffffc8488a FS: 00007f92701cb6c0(0000) GS:ffff8881261c2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0f5af71440 CR3: 00000000262e0000 CR4: 0000000000350ef0 Call Trace: kfree_skb_reason include/linux/skbuff.h:1279 [inline] kfree_skb include/linux/skbuff.h:1288 [inline] gro_cleanup+0x300/0x640 net/core/gro.c:815 __netif_napi_del_locked+0x2e0/0x3c0 net/core/dev.c:7301 __netif_napi_del include/linux/netdevice.h:2876 [inline] gro_cells_destroy+0x16a/0x430 net/core/gro_cells.c:117 ip_tunnel_dev_free+0x19/0x30 net/ipv4/ip_tunnel.c:1102 netdev_run_todo+0xcd7/0xea0 net/core/dev.c:11300 setup_net+0x5db/0x830 net/core/net_namespace.c:392 copy_net_ns+0x32e/0x590 net/core/net_namespace.c:518 create_new_namespaces+0x3d3/0x700 kernel/nsproxy.c:110 copy_namespaces+0x438/0x4b0 kernel/nsproxy.c:179 copy_process+0x1700/0x3b80 kernel/fork.c:2433 kernel_clone+0x21e/0x870 kernel/fork.c:2845 __do_sys_clone kernel/fork.c:2988 [inline] __se_sys_clone kernel/fork.c:2972 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2972 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f926f38e969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f92701cafe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f926f5b6160 RCX: 00007f926f38e969 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000042000000 RBP: 00007f926f410ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f926f5b6160 R15: 00007fff8df30f78 --- 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