From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.167.198 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793988550; b=uHxfgVyeV2/RL4ZVArc11qycWdD6qT3qrFJYtlm6eegQM0h/yUIASLisBoISuHigr4lP QtBi010AiDyc1ZsU3ejNXvj9qoSWYyqSDELJBNOw7CNB3xw26KeFYFl4OfnZhAJjNPUB2 /+PC4Rkw4JjgzJebCdr/zKKai1ovs5w1EolLD1XsdYNYIkCb1aJjKbPwwXDQtC7b7XCc/ bgxZYhSFdZ3RXYd+QeSOadDYqz49S2tfdzo6m2DhSMf1FCC553eLqabbR0xjuNrEM/TYj zAzmTYqlX9vWv5tZ0LAx5bvE0jRzBrFEkminwmCkwmZZbOMDKBXP1Z4wbQtDOXw6ZQg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793988550; h=DMARC-Filter:Received:X-Google-DKIM-Signature:X-Forwarded-Encrypted: X-Gm-Message-State:MIME-Version:X-Received:Date: X-Google-Appengine-App-Id:X-Google-Appengine-App-Id-Alias:Message-ID: Subject:From:To:Content-Type; bh=tHsWuUqZawgO/+5zHIysVA31VVEjDt03dHJYlp7sVuw=; b=2fLj22N2nI22t/XMVbt2v6SNYPshtkqFW1quJgo3Ooj971zUTNxy9v9tw90J9kAymt75 CGfiCyGmI/jo3ydrlXzAO6SBjV+QGvJUG3pPFzGATZQsQnariZ7iMQ6xv21f4MYweND3t QivVQ17F0fIW5XkVaxEQtJG3TlU0WyAQOhnJtq5i7ITEmMAnlf1JGAuD89glwsyvjF4ag Im8FmlYV6IiR+3B2/7oeS8L667t4AitjYWYSG1sZubLuHtRR5YP6+FUls1hBnD4NEl5kQ u+FWwlIcRj/lIqNbrqVFlUSj/0ePERCcebiAvvPZklHJ3Hzww2ZeRBJTf3UtWRTFJDg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=fail header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.remote-ip=209.85.167.198 Received: from mail-oi1-f198.google.com (mail-oi1-f198.google.com [209.85.167.198]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AFC62606A32D for ; Fri, 6 Nov 2026 18:09:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org AFC62606A32D 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-f198.google.com with SMTP id 5614622812f47-5384e381fbbso711774b6e.2 for ; Fri, 06 Nov 2026 10:09:09 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1793988548; x=1794593348; 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=tHsWuUqZawgO/+5zHIysVA31VVEjDt03dHJYlp7sVuw=; b=QsdNYdBmFZJLv1sEkuBD/mYBAZVPDFbiw1TI3n1OMxzDRCwAjsnmEmn/ZqmAyjfiT4 vgp+DmwK3SCjf8sRxrRXpmJ94I/iIThL3+5v3lTfM+kbuhClEPSzjU7fOFDTxjIRZx28 FCl+LvUrK3SWjBqXyINDjET1Ijik0PtK6erNWyoYJ40SCqkXdwBipyL6ZwdaOEgSP6Io v66HvarkhjuWS51BfUh9IX0hDJclbLOGM05jrw5KHFSkWHGYhRPiogADawL4memRRofA cPPNK/4vGrbyho5KxMl5VTP6OD/BnZeah204ep/PPRn3HQ+YsLQdNsEeclMFQ8d17u0m VGHA== X-Forwarded-Encrypted: i=1; AKwUvBwkJ8ciybvvFnFG1orgCXlbr1q8SocYIApjst4XKjbFCGXTGexrWIvy2XyRH48rNLv3PjZC9ss=@vger.kernel.org X-Gm-Message-State: APuU4Z/w+dh9ORtS6Afck/1C8Dkbd+9SlMLdxbAIel5Tb16tePMxlDXm FFwE7K3ZPkWZgs+aW1dTTjrL3duY03q3S4/HH3pd9aAdB3pdE1hDXmdABDwVXGK02t2iqC19dm9 eZvjDv+gorjtcS9dym/iL2bPQ2efKhCjpL3R/8KwIjx5jD+y+hYOPxMcXIME= X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-Received: by 2002:a05:6808:c298:b0:55b:f8c9:298e with SMTP id 5614622812f47-567e1047884mr2818860b6e.25.1793988548779; Fri, 06 Nov 2026 10:09:08 -0800 (PST) Date: Fri, 06 Nov 2026 10:09:08 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6aee17c4.8be4ead1.3b45e1.0199.GAE@google.com> Subject: [syzbot] [net?] [nfs?] WARNING in svc_destroy From: syzbot To: Dai.Ngo@oracle.com, anna@kernel.org, cel@kernel.org, davem@davemloft.net, edumazet@kernel.org, horms@kernel.org, jlayton@kernel.org, kuba@kernel.org, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, neil@brown.name, netdev@vger.kernel.org, okorniev@redhat.com, pabeni@redhat.com, syzkaller-bugs@googlegroups.com, tom@talpey.com, trondmy@kernel.org Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 05441d697f7f Merge tag 'cocci-7.4-rc1' of git://git.kernel.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=14721d2d580000 kernel config: https://syzkaller.appspot.com/x/.config?x=1cf189394a856f11 dashboard link: https://syzkaller.appspot.com/bug?extid=8cbdf9aa6c281a4e6bbe compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/e8f55ecc1d55/disk-05441d69.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/db66972c51fd/vmlinux-05441d69.xz kernel image: https://storage.googleapis.com/syzbot-assets/6628bc03aa4a/bzImage-05441d69.xz AI-generated root cause summary: In fs/nfs/callback.c, nfs4_callback_up_net() first initializes an IPv4 TCP listener transport via svc_xprt_create(..., PF_INET, ...), which links the transport onto serv->sv_permsocks. When a subsequent call to svc_xprt_create(..., PF_INET6, ...) fails with an error other than -EAFNOSUPPORT, nfs4_callback_up_net() returns the error immediately without tearing down the existing IPv4 transport. As a result, nfs_callback_up() unwinds on error and calls xprt_svc_destroy_nullify_bc() -> svc_destroy(), which triggers the WARN_ONCE(!list_empty(&serv->sv_permsocks)) warning because the IPv4 transport is still attached to the service, and subsequently frees the service while leaving the active listener with a dangling pointer. full analysis: https://syzkaller.appspot.com/x/ai_root_cause?x=8cbdf9aa6c281a4e6bbe IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+8cbdf9aa6c281a4e6bbe@syzkaller.appspotmail.com NFS: callback service start failed ------------[ cut here ]------------ SVC: permsocks remain for NFSv4 callback WARNING: net/sunrpc/svc.c:532 at svc_destroy+0x299/0x330 net/sunrpc/svc.c:532, CPU#1: syz.2.321/6994 Modules linked in: CPU: 1 UID: 0 PID: 6994 Comm: syz.2.321 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026 RIP: 0010:svc_destroy+0x29d/0x330 net/sunrpc/svc.c:532 Code: 48 b8 00 00 00 00 00 fc ff df 49 8b 5d 00 48 8d 7b 18 48 89 fa 48 c1 ea 03 80 3c 02 00 75 67 48 8d 3d 17 5e 78 07 48 8b 73 18 <67> 48 0f b9 3a e9 d0 fd ff ff 48 8b 7c 24 08 e8 bf 13 86 f7 e9 a5 RSP: 0018:ffffc900042af860 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffffffff9040ba80 RCX: ffffc900063d9000 RDX: 1ffffffff2081753 RSI: ffffffff8c37e800 RDI: ffffffff927aee30 RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff888035744000 R13: ffff888055f04c00 R14: ffff88802de30000 R15: ffffffff9cd5b540 FS: 00007ff81118f6c0(0000) GS:ffff88812257c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c29af61 CR3: 0000000056a04000 CR4: 00000000003526f0 Call Trace: nfs_callback_up+0x511/0xad0 fs/nfs/callback.c:236 nfs4_init_callback fs/nfs/nfs4client.c:327 [inline] nfs4_init_client_minor_version fs/nfs/nfs4client.c:379 [inline] nfs4_init_client+0x236/0x420 fs/nfs/nfs4client.c:429 nfs_get_client+0xf38/0x1230 fs/nfs/client.c:467 nfs4_set_client+0x3f6/0x640 fs/nfs/nfs4client.c:763 nfs4_init_server.isra.0+0x5be/0xf80 fs/nfs/nfs4client.c:1014 nfs4_create_server+0x185/0x2b0 fs/nfs/nfs4client.c:1063 nfs4_try_get_tree+0x93/0x140 fs/nfs/nfs4super.c:228 nfs_get_tree+0xa61/0x1440 fs/nfs/fs_context.c:1621 vfs_get_tree+0x92/0x320 fs/super.c:1881 fc_mount fs/namespace.c:1282 [inline] do_new_mount_fc fs/namespace.c:3910 [inline] do_new_mount fs/namespace.c:3986 [inline] path_mount+0x7d0/0x2850 fs/namespace.c:4337 do_mount fs/namespace.c:4350 [inline] __do_sys_mount fs/namespace.c:4565 [inline] __se_sys_mount fs/namespace.c:4542 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4542 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff81039fb19 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:00007ff81118f028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007ff810625fa0 RCX: 00007ff81039fb19 RDX: 0000200000000480 RSI: 0000200000000440 RDI: 0000200000000400 RBP: 00007ff810437b70 R08: 00002000000004c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff810626038 R14: 00007ff810625fa0 R15: 00007ffd2a563db8 ---------------- Code disassembly (best guess): 0: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 7: fc ff df a: 49 8b 5d 00 mov 0x0(%r13),%rbx e: 48 8d 7b 18 lea 0x18(%rbx),%rdi 12: 48 89 fa mov %rdi,%rdx 15: 48 c1 ea 03 shr $0x3,%rdx 19: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 1d: 75 67 jne 0x86 1f: 48 8d 3d 17 5e 78 07 lea 0x7785e17(%rip),%rdi # 0x7785e3d 26: 48 8b 73 18 mov 0x18(%rbx),%rsi * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: e9 d0 fd ff ff jmp 0xfffffe04 34: 48 8b 7c 24 08 mov 0x8(%rsp),%rdi 39: e8 bf 13 86 f7 call 0xf78613fd 3e: e9 .byte 0xe9 3f: a5 movsl %ds:(%rsi),%es:(%rdi) --- This report is generated by a bot. 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