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 33B51342C98 for ; Fri, 21 Nov 2025 09:20:32 +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=1763716833; cv=none; b=BreJRcRpK/tYxmIqshasoK4cypB9AqEh5TyJCtpQZBeYcWy+Oa0mmKHGluyH3zdCvU/ZXhypF1o/nt1lVjreC+tx9OaQUz+Q2t/+oUGJ5XbhqXCtCCLjNNTHDVhig4ILKPFlhjdKPEdkrixldKocblDyGwx3s2YiLAkszP3SXC8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763716833; c=relaxed/simple; bh=cL1RS04Vlbg5/isdthq1+y1Pb3yMmqLyOIAoOc+x41Q=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=f5GurzJBnNFLwA54nfu+y7QNOmKLuQcnaSOW9km45LQaxYt66neCTByzJ7wdO4O4CoKH6iufJzp/lBol81YEhjPlXSkLJYpfopFKfPFSXqFWKNm6L2RTk/BdQHmgtPnRnOKr6g/0q0X71QV7Q66Kr1f3oi8fgqyL7hwLX6bGgjQ= 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-43478824a6fso17989875ab.3 for ; Fri, 21 Nov 2025 01:20:31 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1763716831; x=1764321631; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=Y57Wj2emBMA0I4GdDAAg7azio1mhTOb6C4GKyshX+cY=; b=ts9BfDrh5EymfKTl3HKKPl7zB/HDMrXu7ndXzdIDXv3GoemmSCf9IXPLiQbvfm8PWz RquF9q/HHuimSKMSHbnJ0QC7FJZVqdtjho99VoQRVaMQ/xPoyrfhumlr+i29BNNRgb2n ZbugvyfwO5+oIffHeqfj6FfET1lnclgapLh3dpbXvmCGqhM1XZWoHJfBzlKk7xQzrKw+ elJy7WfOrQJqH9ShEitXadedSw7kLDvX7fEKHhksxuq4FYRr6h4pZjoewtBu78R4B/wc GcaAXHfOw/YsM0FWfeMxmxL62cWfFhQoQzbGiMehI7dVsPjkQSTEz9esBhh+UbOqNuJO GKsQ== X-Forwarded-Encrypted: i=1; AJvYcCWojay/SQNOO/Y30gtApAEBiZN3W2ITDoO7cn0gFwScHykRYtZWSXV97LtsW4SbOPuHxC9mvthXZ9ZeeL4=@vger.kernel.org X-Gm-Message-State: AOJu0Yzwb+LOp3emRIBgv78Y7MOAcx/v98A/ivHG+FM0+5mPv5mKV3Ie Kgr3ru2mSbCHsK0OVGRxGMsRAHyQBvZvowdPHqknsvG3mofyYhZFIvzeno+9xTa+/ITDiUueRhO hH9QVUF1NY6F9qg69fQSlFYNlJY5FrWbydqcWipl7du5oHE4HpWrVlfpcoVo= X-Google-Smtp-Source: AGHT+IEac/g/gQ2aIQk1kyITjzB+Ny9W97Qb1XEBlpBiMdpCj5JGgoWXsiWSPhL9UBO6t5j28HdwCKBQ/U0+5yIxQpUE1U/X72h0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:3f06:b0:434:77cf:9df with SMTP id e9e14a558f8ab-435b8e790f1mr18431775ab.32.1763716831338; Fri, 21 Nov 2025 01:20:31 -0800 (PST) Date: Fri, 21 Nov 2025 01:20:31 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69202edf.a70a0220.2ea503.004c.GAE@google.com> Subject: [syzbot] [hams?] WARNING: refcount bug in nr_del_neigh (2) From: syzbot To: davem@davemloft.net, edumazet@google.com, horms@kernel.org, kuba@kernel.org, linux-hams@vger.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: 407a06507c23 mlxsw: spectrum: Fix memory leak in mlxsw_sp_.. git tree: net console output: https://syzkaller.appspot.com/x/log.txt?x=10c11b42580000 kernel config: https://syzkaller.appspot.com/x/.config?x=e46b8a1c645465a9 dashboard link: https://syzkaller.appspot.com/bug?extid=3f991c449d23d41216a2 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/62d11ae9564e/disk-407a0650.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/997cf054bfb9/vmlinux-407a0650.xz kernel image: https://storage.googleapis.com/syzbot-assets/827a9f03aefe/bzImage-407a0650.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+3f991c449d23d41216a2@syzkaller.appspotmail.com ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 13218 at lib/refcount.c:28 refcount_warn_saturate+0x11a/0x1d0 lib/refcount.c:28 Modules linked in: CPU: 1 UID: 0 PID: 13218 Comm: syz.3.2115 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:refcount_warn_saturate+0x11a/0x1d0 lib/refcount.c:28 Code: 40 58 be 8b e8 07 a4 f9 fc 90 0f 0b 90 90 eb d7 e8 1b 88 36 fd c6 05 b9 84 dd 0a 01 90 48 c7 c7 a0 58 be 8b e8 e7 a3 f9 fc 90 <0f> 0b 90 90 eb b7 e8 fb 87 36 fd c6 05 96 84 dd 0a 01 90 48 c7 c7 RSP: 0018:ffffc9001a9a7a58 EFLAGS: 00010246 RAX: df5324e680d95e00 RBX: 0000000000000003 RCX: ffff88802f279e40 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff1bba684 R12: dffffc0000000000 R13: ffffffff8c7f8848 R14: ffff888056783c3c R15: 0000000000000000 FS: 00007f267354c6c0(0000) GS:ffff88812623b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000007e2f0000 CR4: 00000000003526f0 Call Trace: nr_del_neigh+0x16c/0x1d0 net/netrom/nr_route.c:440 nr_rt_ioctl+0xb1b/0xd50 net/netrom/nr_route.c:682 sock_do_ioctl+0xdc/0x300 net/socket.c:1254 sock_ioctl+0x576/0x790 net/socket.c:1375 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f267278f6c9 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:00007f267354c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f26729e5fa0 RCX: 00007f267278f6c9 RDX: 00002000000000c0 RSI: 000000000000890c RDI: 0000000000000013 RBP: 00007f2672811f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f26729e6038 R14: 00007f26729e5fa0 R15: 00007fff2eed0978 --- 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